Stellar Catalogs

This page lists a number of stellar catalogs which might be useful for reduction of TASS images.

Brian Skiff posted a very nice history of recent stellar catalogs to sci.astro.amateur; it contains a description of many of the new and not-so-new catalogs, their properties, and many URLs. I recommend it highly. Arne Henden has written a brief description of the Hipparcos and Tycho catalogs. If you use the Tycho catalog for photometry, take a look at converting Tycho magnitudes to the standard scale. Brian Skiff has created a very useful set of tables which give unreddened colors of stars in several different photometric systems.

Index of catalogs:


TASS tenxcat catalog

Catalog last modified Sept 5, 1999

This contains measurements in (mostly) V and I and (a little) R for about 367,000 stars nears the celestial equator. It is based on data taken by several TASS Mark III cameras. The gzip'd file is 9.9 Meg in size, and uncompresses to a file about 52 Meg in size.


Spectral type vs. (B-V) and (V-I) color from Hipparcos

The Hipparcos main catalog contains (B-V) and (V-I) color index values for many stars from various reference catalogs (not measured by Hipparcos itself), as well as spectral types from other reference catalogs. I have made graphs showing the relationship between spectral type and (B-V) or (V-I) color index. The spectral type is coded in the following way: O=0, B=10, A=20, etc,. then add the sub-class value. For example, an F5 star would have code 35 (30 + 5).

For good measure, here's (V-I) versus (B-V) color index. Note the left turn and bifurcation in the locus for red stars; I think that some of this is due to the variety of reference catalogs used, but some may be intrinsic and due to luminosity class.

Skymap 4.0

One catalog which might be of use is called SKYMAP, created to aid spacecraft figure out their orientation. It's a compilation of many, many other stellar catalogs. You can read more about it at the Flight Dynamics' Skymap 4.0 WWW site. It contains about 299,000 entries, which, if distributed uniformly around the sky, comes to about 7 per square degree. That would imply that about 7000 appear in a 3-degree wide strip around the celestial equator. Each entry has position (J2000), proper motion, parallax, several magnitudes, and more. The entire catalog is 142.6 MBytes in size, and can be acquired via FTP from ftp://fdd.gsfc.nasa.gov/pub/skymap/skymp40a.cat.


Landolt photometric standards

Arlo Landolt has written several papers describing his work in creating a network of standard stars around the sky. His papers contain increasingly larger compilations of increasingly fainter stars, and have measurements in five passbands (UBVRI). You can find his work in Astronomical Journal, for the most part. Look in Landolt has requested that his catalogs not be distributed in electronic form, but may provide copies himself. Brian Skiff has carefully determined accurate positions for all the stars in the Landolt photometric catalogs. You can find precise positions of the Landolt stars (but without the photometry) on the Lowell Observatory FTP site, together with Brian's explanation of the astrometric procedures.

Added July 12, 2002

Bill Gray of Project Pluto has merged the good positions from Brian Skiff with Landolt's photometry (plus Tycho photometry) for stars from the papers referenced above. His file is plain ASCII text; some stars are missing data in some columns.


Twin Astrographic Catalog

This catalog was constructed by the US Naval Observatory based on photographic plates taken 1977-1986. It covers 705,679 stars between Dec=-18 to +90 degrees, with magnitudes down to about B=11.5. This catalog has the highest positional precision of any existing, publicly available source: the average position is about 90 milliarcseconds per coordinate at epoch of observation. Some of the catalog is available now, and version 1.0 is scheduled for release by the end of August 1996. For more information, look at the WWW site for the Twin Astrographic Catalog.


Brian Skiff's compilation of bright northern standard stars

Brian combined information from several different catalogs to produce a list of bright stars in the northern celestial hemisphere, distributed all over all declinations. He tried to be very careful in selecting only stars with very sound Johnson-Cousins photometry. For more information, read Brian's document on Bright Northern BVRI Standard Stars.

I have reformatted Brian's list so that it contains the position in decimal degrees, and so that the magnitudes (not colors) are given for each entry.

Glenn Gombert has made a "finding chart" for the fields with Brian's stars. different catalogs


Brian Skiff's list of standards in M67 and NGC 1275

Brian has provided a list of standard stars in the "dipper" asterism in M67, and near the galaxy NGC 1275. These are far from the celestial equator, but may be useful for a system which covers the entire sky. For more information, read Brian's document on standards in M67 and NGC 1275.


Brian Skiff's list of very red standards

In vsnet-chat message 5427, posted 30 July 2002, Brian Skiff wrote:

The list below contains reliable red standards that might be suitable for observation of Miras and carbon stars with photoelectric/CCD instruments--- and more generally for seeing how one's system behaves in this regime. These are well observed on the Johnson-Cousins UBVRI system and have reasonably small uncertainties, suggesting they are not greatly variable.

Most of the stars are selected from the various Landolt standards papers, and for the most part are fainter than V mag. 7 and redder than B-V = 1.75, or V-R = 1.0. Although there are additional Landolt red stars, none are well-observed, and the errors on the figures makes them unsuitable as standards. None of the Cousins E-region standards is quite as red as these. Additional _provisional_ southern red standards have been published by Koen et al. (2002MNRAS.334...20K). I show here some well-observed stars with small scatter in the measurements, indicating relative lack of variability.

Arne Henden noted that since the stars are bright toward the red, one might end up using the fainter stars here when observing in VRI colors, but using the brighter stars when doing U-B in order to get enough signal. Because of the slight variability, another suggestion is to observe as many of these stars as possible in hopes of being able to average out the scatter that will inevitably occur in fitting the data.

Many of the of stars are designated or suspected variables, and are at least slightly variable in V (0.03-0.05 mag. range). Except for U-B, however, the _colors_ should be fairly stable. An odd exception is HD 172829 = HK Aql, which is certainly constant. A comparable star in the northern winter sky is HD 27482, which is another strongly reddened ordinary K-giant star. If you can observe stars as bright as these, I recommend you consider them as very red "friends".

Few photometric systems are linear in this color regime. If red stars are on the menu, a suggestion is do two separate solutions: one for stars with B-V < 1.5, and another for stars with B-V > 1.2 (yes, some overlap) that will be used to reduce the red stars only. It is likely that one will need nonlinear terms (usually a cubic) to fit the very-red regime. Arne Henden also noted that since the stars are bright toward the red, one might end up using the fainter stars here when observing in VRI colors, but using the brighter stars when doing U-B in order to get enough signal. Because of the slight variability, another suggestion is to observe as many of these stars as possible in hopes of being able to average out the scatter that will inevitably occur in fitting the data.

 sources
 AAH    Arne Henden photometry files
 C65    Cousins 1965MNSSA..24..120C
 K02    Koen et al. 2002MNRAS.334...20K
 L67    Landolt 1967AJ.....72.1012L
 L83a   Landolt 1983AJ.....88..439L
 L83b   Landolt 1983AJ.....88..853L
 L92    Landolt 1992AJ....104..340L


Brian Skiff's list of colors corresponding to spectral classes

Brian Skiff has put together a table showing the properties of stars of different spectral classes; it might be very useful to gauge the type of a star based on observed colors.

From a message sent by Brian on July 17, 1999:

I've gone through the Cousins E-region and Landolt lists now to get at least rough V-I throughout the range of main-sequence stars and for late- type giants. I suspect that V-I for the earlier type giants (rare in any case) will be quite close to those for dwarfs of the same temperature class, particularly earlier than G0. The list is copied out to:

ftp://ftp.lowell.edu/pub/bas/starcats/uvby.calib

I prepared this originally to have a map for getting rough Mv and color/type from Stromgren b-y colors, which is why the intrinsic Stromgren b-y's are in there. In general the variables to be found by TASS will be mid-range main-sequence stars or late-type giants, so the present list should do fine except right in the galactic plane where things can be reddened considerably. There are lots of spectral surveys along the plane, and these will doubtless help in solving identifications. As you know, I've got a lot of these into machine-readable form along with accurate positions. They are posted at the 'starcats' ftp area, but Fabienne Woelfel at CDS-Strasbourg has been working steadily at getting many of them merged into SIMBAD, so the stars will be recoverable from regular SIMBAD searches.

From a message sent by Brian on June 7, 2002:

The table now shows rough correspondences for J-K, so that 2MASS and DENIS colors can be used as a diagnostic.


Arne Henden's small set of "constant" stars

Arne Henden of the US Naval Observatory (aah@nofs.navy.mil) has made up a nice list of "constant" stars that are well-separated from any bright companions. We might pick these as fiducial stars for relative photometry/astrometry if they fall into the field of some TASS image.

For details and the list of about 40 stars, read Arne's list of constant stars.


FASTT variables near the celestial equator

Arne Henden wrote on Sept 15, 1997:

I've posted on storm the file brightvar.tex, which contains the 90 or so brightest variables from the FASTT survey. These stars should all appear in the TASS dataset, so you should look for them as 'test particles' when searching for variables. Someone can convert the file into a format more easily identified from TASS data (i.e., RA>degrees and remove the formatting).

I (Michael Richmond) reformatted the datafile, although I don't know exactly what the final 4 columns contain.


Arne Henden's small set of astrometric standards

Arne Henden of the US Naval Observatory (aah@nofs.navy.mil) has made up a few small lists of astrometric stars from USNO observations. Here is his explanation:

I've uploaded to storm.fnal.gov under /incoming two files of 'bright' astrometric standards (coordinates good to +-50milliarcsec, J2000):

       brightE.cat  07hr RA  Milky Way  contains RU149
       brightI.cat  12hr RA  out of plane  contains SA104
These stars are all 9.5-11.0 in R, and should be about optimal for the TASS cameras. There has been no selection regarding variability or crowding. I can supply postscript 'finding charts' for these fields (or hardcopy for those without postscript capability).

I will add two additional files this week of photometric standards within these same fields.

These two fields should provide some interesting results. The E field passes through the Milky Way, though far from galactic center, and contains some 91,000 stars to R=17. The I field is relatively uncrowded, and contains some 21,000 stars. Using the E field standards should tell you how well the TASS cameras work in crowded regions; the I field standards will give you a better measure of the astrometric and photometric accuracy of the cameras in general. Since I have stars much fainter than the limiting magnitude of the TASS cameras in these fields, if observers supply me with their extracted data files, I can see what the true limiting magnitude and saturation magnitude of the cameras are under varying conditions and filters.

You can find the lists themselves at:


Standard BVRI magnitudes of stars in SMSP Area B

Arne Henden has observed three areas within the SMSP "B" field with one of the US Naval Observatory's telescopes, in the standard Johnson-Cousins BVRI passbands. Here's his description of his results:

These standards are in three 11x11arcmin regions in SMSP-B. They range in brightness from V=8.6 to V=17, and so should be good to use in determining faintness limits on the TASS frames. The astrometry is good to about +-0.1 arcsec; the photometry is typically 0.01mag accuracy, using a 12arcsec aperture. They were determined on the basis of three consecutive photometric nights on the 1.0m telescope. I don't think there are any variables lurking in this set, but to do really good secondary standard work, you would need to take one or two additional photometric nights spaced from the original three to remove long period variables. Also, I do not have very many 'bright' stars in this set; I could have selected my fields a little more carefully to give you a few more brighter stars. Maybe next time!

You can grab two versions of his catalog. In each catalog, a value of "99.00" for a magnitude or color means "no data". Also, an entry of "000" in the GSC column means the star doesn't appear in the GSC.


UBVRI magnitudes of stars within +/-5 degrees of the equator

Arne Henden has created a small catalog of bright (V <= 15) stars near the celestial equator. Here's his description of the catalog, posted 4/21/98:

I've placed on my anonymous ftp site the file

ftp://ftp.nofs.navy.mil/pub/outgoing/aah/photom/ubvri.tass

which is a preliminary list of stars that I have observed in UBVRI colors within +-5 degrees of the equator and brighter than V=15. I am in the process of rereducing hundreds of nights of photometry, and so will extend this list on an infrequent basis. While I do not consider these stars of high enough quality to be 'standards', they are good enough to be used as checks for any TASS photometry. In addition, for northern/southern strips like Glenn's, they can be used as a 'last resort' standard list since there are few Landolt standards outside the +-1 degree region.

A few months later, Arne posted a much larger version of this catalog, containing stars all over the sky. Here's his message from Dec 8, 1998:

I've uploaded to

ftp://ftp.nofs.navy.mil/pub/outgoing/aah/photom/ubvri.cat

the latest incarnation of my personal photometry file. Like the previous file, this one contains stars observed with the 1.0-m telescope in at least B & V (and often BVRI) with errors in V and (B-V) less than 0.05mag. The current catalog covers the last 3.5 years and contains 40590 stars (culled from a master list of 291K stars). I'm slowly working my way backwards through my CDs and expect this list to about double by the time I am through (early next year). For example, there are many fields that I only observed once and are therefore removed from this culled list, even though the photometry would be good enough for most visual use. Likewise, there are some fields where a poor night got mistakenly included (and therefore increased the photometric errors), and others that have V&I photometry but not B, and again were removed from this compilation. As before, you are welcome to personal use of this list, but must contact me before using the photometry in any refereed journal.

I have modified its format slightly -- see the comments at the start of the file. MWR

The current list (last updated Jan 14, 1999) has 2 versions.


UBVRI photometry of stars in IC 4665

Brian Skiff wrote to VSNET on Sep 2, 2002:

The list below shows coordinates and UBVRI photometry for stars in the field of the large open cluster IC 4665. Most of the data are from the work of Menzies & Marang (1996MNRAS.282..313M). They observed the stars on at least three nights each from South Africa directly against Cousins E-region primary standards. The observations of the stars in SA 109 show how well they match the Landolt system.

For one IC 4665 stars and for two more in the near region, I show Landolt data for comparison and to extend the standards collection. L83a indicates data from the main 1983 Landolt paper (1983AJ.....88..439L), L83b the "equipment stability" paper (1983AJ.....88..853L), and L92 indicates the main 1992 standards paper (1992AJ....104..340L).

I have modified its format slightly -- MWR


Compact, bright groups of stars with good photometry

Jean-Claude Pelle responded to a request for groups of bright stars (mag 7 to 10) with good photometry:

Using Arne Henden (HEN) and Brian SKIFF (LON) catalogs, here is the best I found using the following criteria

- DC >= -30
- DC <= +30
- R mag >= 7.0
- R mag <= 10.0
- V, R and I magnitudes all present
- 4 or more stars in the FOV, 3 stars if large difference 
        in (V-R) or (V-I) as for LONEOS NGC-4564.

Some fields are common to HEN and LON, as SW_AND (by combining you obtain 5 stars, 4 of them with almost the same colors indices.

More richest fields may be not suitable for the large arcsec/pixel scale of the MARK-IV.

For Arne HENDEN catalog, the object name was built as follows:

- the name of the *.dat file
- the row number of the star in that file

For Brian SKIFF catalog, the name is the one in his catalog.

In the attached file, magnitudes and color indices are rounded to 0.01.

Raising the bar to magnitude 11.0 will enlarge the available fields.

I have modified its format slightly -- MWR

The list has 114 stars.


US Naval Observatory's astrometric catalog A1.0

This description provided by Brian Skiff, and is slightly edited.

As some of you may know, the U. S. Naval Observatory in Flagstaff has produced a colossal star catalogue called "A1.0". The catalogue contains almost 500,000,000 detections, including stars, galaxies, etc. The data will not in general be available except for scientific use, and cannot be used in commercial applications. The general Web site describing the catalogue can be found at:

http://www.usno.navy.mil/pmm

The site includes links to two third-party search utilities, one from Doug Mink at SAO/CfA and the other to the Lowell Observatory site.

Since Lowell Observatory folks will making use of the catalogue for various purposes, Bruce Koehn of the Lowell staff has made a Web page with a form for searching small areas of the A1.0 catalogue. The URL is:

Actually, this WWW site now searches the improved, USNO A2.0 catalog. --- MWR Oct 6, 1998

http://asteroid.lowell.edu/cgi-bin/koehn/webnet

This is the top page for various asteroid-related products. Included is Ted Bowell's 32,000+ asteroid orbital element database, asteroid search routines, and other goodies. There is also a link to "refnet", which is the star catalogue search form.

The search form includes access to the full A1.0, the "SA1.0" faint astrometric subset (for use with small CCD fields, for instance), and also the complete PPM catalogue (480,000 brighter stars). The search inputs include RA/Dec, search area, magnitude, and so on; the output can be sorted by RA, radius from search center, etc.

The output itself includes the A1.0 position (equinox 2000 at epoch of the POSS-I blue plate used for the scans, i.e. about 1950-1955), the red and blue magnitude, the radius from the search center, and the position angle. At the moment the p.a. runs the wrong direction (i.e. sweeps around from north to _west_), but this will get fixed eventually. The magnitudes have been adjusted only very approximately, and possess zero-point errors of up to a couple of magnitudes. The colors inferred from the red/blue magnitudes can likewise be completely non-physical---I've found stars with "blue minus red" colors of -3 to -5, which cannot occur in the real world except in blue jeans and lapis lazuli. I'm finding the blue magnitudes are closer to reality than the red ones.

The form defaults to a search area 10 arcminutes square. Unles you are well outside the Milky Way, this results in very long star lists. I would advise changing this to at most 1'-3' (60 or 180 arcseconds on the form).

Like other catalogues built from scans of photographs, there are gaps around bright stars (often including the bright star itself), bright galaxies, bright globular clusters, etc., where the plates were simply black and the star-finding algorithm couldn't operate. By "bright", I mean stars brighter than mag. 10-12, and galaxies with total V magnitudes brighter than mag. 12 or so---stuff that's completely saturated on the Schmidt plates.


HST Guide Star Catalog: equatorial grid

Following Arne Henden's suggestion, I have selected a very small subset of the HST Guide Star Catalog for TASS use. Starting with the GSC v1.1, I selected stars as follows:

The result is a collection of brightish stars which form a very crude grid around the celestial equator. Within a typical 4x3-degree TASS image, one can count on finding about 100 stars --- adequate for astrometric calibration. Keep in mind that the magnitude values of GSC stars are often rough.

I created a catalog file in very simple ASCII format, one line per star, like this:

        GSC0000100197    1.2327    0.2195    12.15
where each line contains 4 items:

The catalog contains 26,653 stars, with the following distribution in magnitude:

 mag        8.0   8.5   9.0   9.5   10.0  10.5  11.0  11.5  12.0  12.5  13.0
 nstar      200   490   678  1053   1768  2877  4560  7016  5670  1336  1005

You can download either the ASCII file itself, or a zip'ed version.


Variable stars near the celestial equator

Bohdan Paczynski was kind enough to provide a subset of stars from the General Catalog of Variable Stars which might be of interest to TASS workers. He choose stars with

I have slightly modified the list, removing stars with invalid coordinates, and precessing the coordinates to the equinox 2000.0. I have heard that the positions of stars in the GCVS aren't very good, so don't be surprised if stars aren't quite at their predicted coordinates. The list contains 386 stars, and has a simple ASCII format, one line per line. Here's the header, plus a few representative lines:


# Stars from the 4th edition of the General Catalog of Variable Stars
# with peak magnitude brighter than 12 mag, and (1950.0) declination
# in the range -3 < declination < +3 degrees.
#
# A period of "0.00" means that no period is known.
# A type of "*" means that no type is given.
# The "mag" column contains the "maximum magnitude (light)" value from GCVS
# Coordinates precessed to equinox 2000.
#      Michael Richmond, March 4, 1997 
# Fixed precession, now _really_ J2000.
#      Michael Richmond, April 11, 1997
#
# name     type           RA  (2000)  Dec    mag    period   spectrum
#----------------------------------------------------------------------------
RY___PSC   RRAB          2.91929   -1.69688 11.820     0.53 F0-F6
VV___CET   EW/KE        13.93464   -1.36275 10.300     0.52 A5
Z____CET   M            16.69036    0.01545  8.400   184.81 M1E-M6.5E
AN___CET   SRB          18.56335   -1.29226  8.370     0.00 M4

Note added April 11, 1997: Arne Henden pointed out that I had failed to precess the coordinates properly to J2000. I have now done so, and replaced the earlier, incorrect version of this catalog on this WWW site.


Variable stars from FASTT catalog, near the celestial equator

See more recent version 3/5/99 below

Arne Henden writes on November 3, 1997:

I've uploaded to storm the file brightvar.fasst, which gives about 200 variables from the FASTT survey that are probably bright enough to appear in the TASS survey. Ron Stone and I will be giving a poster paper at the January AAS meeting, and I would like to present any TASS photometry that we might have on these variables. Glenn should probably look at his difcal output to see if any of these variables appear there, and Chris should look for them in the dbms when more data is uploaded.

On Feb 4, 1999, Arne Henden writes:

I've put the 1600 variable stars from the first FASTT paper on our anon ftp site as

ftp://ftp.nofs.navy.mil/pub/outgoing/aah/fastt1/henden.tab2.tex

Note that it is in TeX format; to use it, you will have to strip out the various formatting characters.

The upcoming second FASTT paper has about an equal number of variables, primarily in the Milky Way fields E,F,M,N where we subsampled in the first paper to reduce processing overhead (and therefore overlooked 80 percent of the variables). I'll post the new variables on the ftp site when we submit the paper.


Variable stars from FASTT catalog which match IRAS sources

Brian Skiff writes on Feb 15, 1999:

I have matched the recent FASTT equatorial variable-star survey (Henden & Stone 1998, AJ 115,296 = 1998AJ....115..296H) against the IRAS point-source and IRAS "faint-source" catalogues using the Strasbourg VizieR facility. Below are the 160-odd match-ups that were found within 20 arcsec of the highly-accurate FASTT coordinates. This search radius is similar to the major axis of the typical IRAS position error ellipse. All but a few of these correspond to cool AGB variables, where the 12/25 micron IRAS flux ratios are > ~1.5, with generally _no_ detection at 60 or 100 microns. The only two IRAS coincidences with odd IRAS "colors" are two extragalactic objects: one is a quasar (FASTT 159), the other is the center of a nearby galaxy (FASTT 543 = NGC 4653). With z=0.92, the quasar is presumably the most distant object in the FASTT survey!

The list below is a stripped-down version of the on-line FASTT catalogue, retaining only the name and coordinates from the original. Appended to the end of each line are "new" IDs, defined as names either not linked or not present in SIMBAD. While all the ordinary IRAS point-sources are present in SIMBAD, most of the "faint-source" IRAS objects are not. If the IRAS name is already linked with a variable-star name, then the GCVS name alone is given. Note that by linking the names, in many cases the FASTT variables suddenly become well-studied, with lightcurves, spectral types, observations outside the visible, and a substantial bibliography.


Variable stars from Tycho catalog, near the celestial equator

Arne Henden writes on July 23, 1997:

I've posted on our ftp server under /pub/outgoing/aah/tass the file teqvars.dat. This is the list of 735 known or suspected variables in the +-1.5 degree equatorial region from the Tycho catalog. The fields are pretty explanatory, except: the the 'X' in column G means that the star is a GCVS variable; 'X' in column T means it is a suspected variable based on the Tycho photometry; Vma = VTmax, Vmi=VTmin, Vscat=scatter around mean; sVT, sBT are the mean errors; HIP = Hipparcos catalog number; and the first 3 columns are the tycho number (like GSC but with t3=component of star if duplicity seen).

The transformations from Tycho magnitudes to Johnson magnitudes are:

        V = VT - 0.090(BT-VT)
      B-V = 0.850(BT-VT)
in the interval -0.2 < (BT-VT) < 1.8


All known variable stars near the celestial equator

Arne Henden writes on June 1, 1998:

This list contains every known variable (plus a lot of suspected variables) in the +-5 degree zone, with proper J2000 coordinates, and I'd recommend using it when deciding whether a variable is new or already known.


Periodic variable stars from ASAS

Brian Skiff writes on May 20, 2000:

I have completed a scan through the new ASAS list of periodic variables (Pojmanski 2000, astro-ph/0005236). The purpose was to get accurate positions and reliable identifications as available for the stars. The list is appended below, which is adapted from the original with some reformatting for humans. Unlike the ROTSE list, I show precise positions and GSC names explcitly, since the source catalogue gives positions to only 0'.1 precision. For uncrowded stars the ASAS positions are usually accurate to the last decimal place. I also include in the table truncated mean I-band magnitudes, amplitudes, and periods. The IDs and other comments are added to the last column.

I matched the source list using the Strasbourg VizieR utility against the GCVS 4.1/NSV/NSVS combination, and against Tycho-2, GSC-ACT, and USNO-A2.0 to get positions and IDs. In SIMBAD I searched a 3-armcin radius from the position of every star for additional matches. Many ambiguous cases were examined on DSS images to look for crowding, or even the mere presence of a star, particularly in the galactic center fields, where USNO-A2.0 has a large number of spurious entries (A1.0 was not always helpful).

Among the conclusions of the catalogue match-up:

  1. As with the ROTSE variables, the proportion of known variables is underestimated by a factor of two. About 28 percent of the ASAS periodic variables are designated variables (109 designated of 381, versus 47 claimed in the paper). This underestimate largely results from...

  2. ...the fact that nearly all the variables reported in the LMC are not new, but were found a century ago at Harvard, and are well catalogued.

  3. A significant portion of the low-latitude objects result from spurious detections of pairs or groups of stars in crowded fields. In several cases I have made no positional identification, and there could well be some errors on my part among those for which I do. In many cases it was not possible to sort out the various problems without access to the source data (images). Every candidate should be checked on larger-scale images for such problems before publication.

  4. Some additional high-weight Landolt standards besides those mentioned in the text are included among the variables. The amplitudes are quite small, and it is likely these are not actually variable. (They would be readily discernable to anyone doing photoelectric photometry.)

  5. Essentially all the stars appear in the GSC, and a majority in Tycho-2. Thus the "new" ASAS names simply add clutter to the literature, and I recommend they not be propagated unless absolutely necessary.

\Brian


Periodic variable stars from STARE

Brian Skiff writes on May 20, 2000:

Although not published yet, here is a list of identifications for new and known periodic variables found by the STARE project run from HAO ( http://www.hao.ucar.edu/public/research/stare/stare.html ). This is the small camera used to find the transits of a planet-like object around HD 209458. The positions, when compared to Tycho-2, are quite good, usually within a couple or three arcsecs. This made the external IDs unambiguous. I ran a match against the GCVS 4.1/NSV/NSVS combination, and have searched a 3' radius at each position in SIMBAD. Because the STARE project is distinguishing variability at such a low amplitude, relatively few of the stars appear in the variable-star catalogues.

The first 80 or so stars are the brighter ones, and all but a few of these has an external ID---an HD number! The fainter stars have far fewer IDs apart from GSC numbers, which I do not give here; a large fraction should appear in Tycho-2 as well. A substantial number nevertheless should have reliable spectral types available from the Case LF 7 field, but these are not in SIMBAD (or VizieR) at present, but coords and IDs can be found at: ftp://ftp.lowell.edu/pub/bas/starcats/lf7.fil

The procedure for obtaining the BVR colors is not explained at the Web site, but it is obvious that these have problems, since a large fraction of them are non-physical, or have uselessly large errors. The first star in the list, for example, needs to have V-R near 0.25 if the B-V value listed is correct. Similarly for red stars, if star 605 (about the 20th entry) really has B-V = 1.405, then V-R cannot be 1.847 no matter what reddening is involved; the V-R here appears to be at least three-quarters of a magnitude in error (expressed to millimag precision of course!). Simply scanning down the B-V column suggests there aren't nearly enough stars in the range 0.5 < B-V < 0.8: the sample seems to have avoided finding any G/K dwarf variables. It looks as though the photometry simply isn't on any standard scale, and the colors especially should be ignored.

\Brian


Periodic variable stars from ROTSE with cross-IDs

Brian Skiff writes on May 9, 2000:

I have gone through the ROTSE1 variables list (2000AJ....119.1901A) to make identifications with external catalogues. The source file provides no identifications of any kind. The list below preserves the ROTSE1 name, their assigned type, and the truncated magnitude, period (days), and (full) amplitude. The collection of IDs follows at the end of each line.

After making a test run on the first 50 stars, it was clear that the number of IDs would be large, about 44 percent, as it turns out. Also, it was clear that the positions are not as good as claimed. Specifically, Figure 2 from the paper is misleading, since it is based on bright, mostly isolated stars. (The figure shows no units.) The fainter variables at low latitude are often in error by 5"-15" due to crowding by similarly-bright stars. A few cases are given in the notes below. Certainly it is misleading to quote the positions to 0s.01/0".1 precision without having made a match with Tycho-1 or 2 or the GSC v1.2/GSC-ACT. Finally, the paper states that they searched the GCVS with only a 28".8 radius (two ROTSE pixels), which will miss a lot of known variables, since the typical GCVS position errors are rather larger.

Given these problems, I first ran the list (in batches of 100 usually) against the GCVS 4.1/NSV/NSVS combination using the Strasbourg VizieR utility searching with a 4 arcminute radius, which will take in all GCVS stars except the very worst cases. I found that about 415 stars are known variables, or 23 percent---the authors missed more than half the known variables from using a too-small search radius. Many uncertain cases were checked using primary source charts. It was very helpful to have the ROTSE periods for the variables, since these matched the GCVS values almost always (there are a fair number of periods at integer fractions, e.g. 1/2, 3/2, 2/1, which some enterprising person could look into).

Next the list went back into VizieR looking now at the IRAS "faint-source" catalogue with a search radius of 60 arcsec, and all reliable cases listed. I found that the position error-ellipses here are clearly underestimated compared to the regular IRAS point-source catalogue, or perhaps they are only 1-sigma instead of the 95-percent confidence intervals as in the point-source listing. The verifiable matches that fell outside the error-ellipses are always directly along the major axes; in all cases where the stars were off the minor axis, the IRAS sources turned out to be galaxies.

Finally, all the ROTSE positions were searched in SIMBAD itself using a 3-arcmin search radius. This allowed me to pick up the main IRAS point-source names (which I have given by preference if there was also a faint-source match), verify the GCVS matches, and make links with numerous other lists. Besides the GCVS links, an additional 20 percent of the stars appear with some physical data in SIMBAD. When multiple IDs are given, these are 'fusions' that need to be made in SIMBAD. (Beating such a list against SIMBAD allows one to fix both the source list and SIMBAD itself.)

I did not make matches with Tycho-1 or -2, with the GSC, or with the BD. This should have been done by the authors, and those positions should have replaced the rather soft ROTSE ones. A Tycho-1/GSC match-up (Tycho-2 not available when the paper was submitted) would have allowed them to correct the ambiguous cases, and avoid cluttering up the literature with "new" ROTSE names, since nearly all the stars appear in the GSC. I did include GSC names (viz. Tycho-1 links) when SIMBAD showed other objects associated with these. I also included HD/BD names when some physical data were present.

Lacking the match-up with SIMBAD, the authors have misclassified a lot of stars. The well-known polar AM Her has been recovered as a delta Scuti; one star with a period of 2.2 days is classed as an RR Lyrae (I suppose the RRs merge into the dwarf cepheids), another such has a period of just 0.1 days (an SX Phe?). There are also some astrophysically interesting cases, such as the O subdwarf PG 1348+369, given as a generic pulsator with a 3.3-day period. I wonder what's going on there? IRAS 18394+2622 is evidently an 0.98-day RR Lyrae. The blue type A2 star BD+16 2944 (latitude +39---not a supergiant!) is listed as a long-period variable. The numerous matches with ROSAT (1RXS) sources will also be interesting to follow-up---most seem to be RS CVn types.

A final note for databasers: the ROTSE magnitudes were adjusted roughly to V using the _uncorrected_ Tycho-1 photometry. This will be good enough for stars of ordinary color, but results in magnitudes rather too bright for the red stars, since the system is operated unfiltered, thus including a lot of far-red flux from these stars (resulting basically in a big curvature in the color transformation). This is easy to check using the (corrected) Tycho-2 photometry for some of the brighter entries.


All stars from Tycho catalog, near the celestial equator

Arne Henden writes on August 7, 1997:

I've put a compressed version of the Tycho catalog on our ftp server under /pub/outgoing/aah/tass. The catalog is eqtycho.cat; a crude reading program is rdtycho.f. This version is only for the equatorial zone (+-5 degrees), is ordered according to increasing right ascension, and consists of 40 bytes/star. I have not cleaned up the catalog by removing the non-astrometric stars and the possible variables. The catalog contains 66174 stars, and is 2.6MB long. This is an average of 18 stars/square degree, but is biased by the galactic plane fields.


All stars from Tycho catalog, within Dec zones

Glenn Gombert and I have created several catalogs which contain stars from the Tycho catalog, but only within certain ranges of Declination. These catalogs may be used with the Mark IV version of "Star" to analyze Mark IV images of the sky.

Each file has a five-column format:

     StarID       RA     Dec      Vt    Bt
where RA and Dec are in decimal degrees. The StarID field may contain a Tycho-style designation.


Loneos low-precision BVRI sequences (all-sky)

You may also look at the distribution of LONEOS standards in a Mercator projection.

Brian Skiff posted this note to VSNET on Oct 29, 1998

My efforts to produce a comprehensive photometric catalogue of faint stars for calibration of wide-field survey images have proceeded apace. The current version posted at:

ftp://ftp.lowell.edu/pub/bas/starcats/loneos.phot

now contains over 14500 stars, and the file is a bit over a megabyte. (N.B. the "version" of the file is given by the date in the second line.) About half the stars lie between V mag. 10 and 13.5, and nearly all the remainder between 13.5 and 18.5. The distribution is unbiased with respect to location, although I have generally avoided fields in the Magellanic Clouds and in the densest parts of the Milky Way, where star selection needs to be rather more careful because of crowding.

The brighter stars are included to provide calibration on _any_ image for those doing sky patrol work with small instruments (typically telephoto lenses with either emulsion or CCD detectors) such as surveys by Takamizawa, Kaiser, and others. The fainter stars are included for use by on-going wide-field surveys with somewhat larger instruments, such as those in search of asteroids, and for calibration of digitized sky survey plates, such as the USNO series of immense star catalogues. These stars in effect more than double the number of sequences available from the Guide Star Photometric Catalogue (GSPC), and reach to similar or fainter magnitude limits. No, we do not have all-sky coverage to mag. 20, but this is what we can do _now_.

Inevitably, most of the stars have only BV photometry, but I have included essentially all the faint VRI photometry appearing in the literature. For little-reddened stars, the relationships between B-V and V-R (or even V-I) are very tight---better than much of the photometry included here. Thus those needing V-R colors (or R magnitudes) can reliably derive them from the BV data given in the file. One conversion, derived from 260 Landolt standards with B-V < 1.3 is:

        V-R = 0.508(B-V) + 0.040   (mean residual 0.017 mag.)

but see also Reid & Gilmore 1982 (MNRAS 201,73) for another transformation (plus one for B-V ---> V-I) based on the Cousins E-region standard-star data. For most survey applications, these are entirely satisfactory.

Recent additions include the following: selected stars in the fields of a few hundred open and globular clusters, chosen as far as possible to be uncrowded (no bright companions closer than ~15") and well away from cluster centers; more of the Demers et al. southern sequences (A&AS 99,437 & 461), which provide groups of several stars down to V ~16 in several hundred fields; additional sequences around active galaxies/quasars/blazars. In many cases these various sequences were among those adopted from the literature in the GSPC, and I have thus been able to revise and extend the GSPC sequences with fainter stars and/or better data and VRI colors. About 275 (among some 1100) relatively bright stars observed by Andruk et al. in 50 northern fields have been added. In all cases I have vetted the published data to look for inconsistent colors and so on. Many papers were rejected entirely as a result of this cursory analysis. The aim is to be able to rely on the data at the 0.05 to 0.10 mag. level. Data from even nominally reliable sources can have systematic errors of similar size, so only a small percentage of the stars here can be considered to be even "secondary standards"; the bulk are merely stars that have been observed by someone whose published results seem to be generally reliable (the GSPC stars are good examples).

By far the largest source of "new" BVRI data are files recently rereduced and made available by Arne Henden (USRI/USNO-Flagstaff). These contain results from several dozen fields along the Equator and around variable stars typically reaching to mag. 18 with both good precision and accuracy. From his several megabytes of data I have selected about a dozen stars in each field. Before being added to the file, his data have been rounded to two decimals and the V-I color calculated from V-R and R-I in the original. This work is an extremely valuable resource for the astronomical community, useful for all kinds of work beyond their original application. The source files can be found starting at:

ftp://ftp.nofs.navy.mil/pub/outgoing/aah

I'll mention again that Michael Richmond (mwrsps@rit.edu) has provided some useful products based on the list. All-sky plots of the distribution of the stars in both equal-area and rectangular projections can be found at:

http://stupendous.rit.edu/tass/catalogs/catalogs.html#loneos

http://stupendous.rit.edu/tass/catalogs/loneos_radec.gif

In addition, Michael has produced a version of the list suitable for many types of automated analysis. This file includes reformatted names, RA/Dec converted to decimal degrees, and gives the BVRI magnitudes explcitly rather than as V magnitudes and colors. This modified file is available at:

http://stupendous.rit.edu/tass/catalogs/loneos.cat

I've done a fairly complete literature survey for Cousins VRI photometry, and I think I have added just about all of it that's any good and that includes faint stars outside of star clusters. I am adding BV data as I come across them, but the collection is not nearly so complete as for VRI. If you know of faint sequences that are missing from the file, particularly those that include VRI colors (even V-R only is helpful), I'll be glad to add them in---just send me the citation. Getting coordinates for stars identified only on charts is not a problem.

from version posted 21 Jan 1999

The file, which now includes over 19,000 stars, contains equinox 2000 coordinates and BVRI photometry (as available) for stars mostly fainter than V mag. 10.0. The median value is V=14.0, so roughly speaking half the stars lie between 10.0 and 14.0, while the other half are between 14.0 and about 18.5 (some stars to mag. 22). It can be obtained from:

The "version number" of this file is given by the date at the top of the list. There is also now a growing file of bibliographic citations from which the data were extracted:

The major addition to the catalogue is that GSC numbers have now been added for practically all stars that have them. This should make the list more readily useful for many people. The GSC match-up was done by Bill Gray (the Project Pluto "Guide" software guy), and I am grateful to have had this done so quickly and expertly.

One significant by-product of the GSC matching is that stars from the Guide Star Photometric Catalogue (GSPC) now have reliable positions. The positions given in the source publication---which was completed before the GSC itself---have errors of typically 2" to 20", but in several fields they are off by 10' or 20', simply wrong. Luckily, the GSPC charts allow the correct positions to be recovered.

Among added stars are a number of sequences along the southern Milky Way by Seggewiss, Lynga, Bok, even a "secret" deep UBVRI sequence by Landolt near eta Carinae. I have also made a start at adding more reliable sequences in the Clouds, but there is still a lot of work to do there. In all cases, I have included stars as bright as V=10.0, since it is clear that many observers will find stars just below the limit of _reliable_ Tycho photometry to be useful for photographic and wide-field CCD sky patrols.

Michael Richmond (Rochester Inst. Technology), of the TASS amateur sky survey group, has kindly produced plots of the distribution of the stars from my list, and posted them at the TASS Web site:

...for all-sky equal-area and rectangular RA/Dec projections. The first URL contains some additional details about data. The figures show that no matter where you're pointed in the sky there is always a set of calibration stars within a few degrees. Large regions near the galactic poles and "downtown Virgo cluster" are particularly well covered. Using these stars, one can make local corrections to the GSC and USNO-A catalogues to place those magnitudes closer to the standard system.

from version posted 29 Oct 1999

I have recently been adding some new photometric data retrieved from the literature to my large list of BVRI photometry of "faint" stars. Most of the additions have been to moderately-bright stars (10 < V < 14) in the southern hemisphere, but some new data was found in all parts of the sky at both high and low galactic latitudes, and in the Magellanic Clouds. The file is intended for use in calibrating sky survey plates and current digital data, providing ready-made sequences for supernovae, variables, etc.

A major change from the last time I made a general announcement about the list (summer 1999) is that two large sets of very faint stars along the Equator and near -30 Dec have been backed out of the list. I made the mistake of actually looking at the data closely (!) and found too many stars with wildly inconsistent colors (errors of 0.5 mag. and more). Despite the loss of some 1500 stars from this source, the total number of stars has grown to about 28,000 with a median V close to 14.0.

All high-weight primary standard stars in the list are now marked with an asterisk next to the V magnitude.

from version posted 19 Jan 2000

My large collection of photometry for faint stars has now topped 30,000 stars with recent additions culled from the literature. The list is intended for use in calibrating wide-field photographic and digital surveys, and contains BVRI data for stars fainter than V mag. 10, mostly between mag. 12 and 18. Substantial useful additions have been made of late, including a couple hundred stars in the fields of bright galaxies. If you have not grabbed a copy in a few months, it may be time for a updated version if you make regular use of it. A date given at the top of each file shows when it was last modified.

The bibliographic reference file has also been amended accordingly:

ftp://ftp.lowell.edu/pub/bas/starcats/loneos.ref (104Kb)

from version posted 14 Feb 2000

I've made some fairly substantial additions to my large BVRI photometric reference file. Chief among these are extracts of sequences around twenty symbiotic variables by Henden & Munari from a paper that is "in press". Arne Henden, nice guy that he his, made his complete photometry files available to me for this. In addition, John Greaves pointed me to the Mermilliod photometry bibliography file on the Web, and this yielded another twenty new sequences in the older literature that I had previously overlooked. Some additional material from recent journals has been added as well.

The star-count is about 31,000; median V is near 13.8, with most stars between mag. 11 and 18. Some brighter standards are included, and for quite a number of fields there are stars as faint mag. 22. The collection is intended for use in calibrating scans of photographic surveys, current wide- field digital surveys, providing "instant" calibration for variables, GRBs, asteroids, supernovae, etc.

Latest version of catalog: 15 Mar 2003. Contains 33,860 stars.


Low-precision UBVRI measurements in AGN fields

In the Oct, 2001, issue of Astronomical Journal is an article titled OPTICAL AND NEAR-INFRARED CALIBRATION OF AGN FIELD STARS: AN ALL-SKY NETWORK OF FAINT STARS CALIBRATED ON THE LANDOLT SYSTEM1 , by JosÉ NicolÁs GonzÁlez-PÉrez, Mark R. Kidger and Fabiola MartÍn-Luis. The abstract:

We present a total of 12,436 photometric measures of 371 field stars of 26 quasars in the visible (UBVRI) and 22,276 photometric measures of 122 field stars of 13 quasars in the near-infrared (JHK), giving a total of 34,712 measures. Of these, 115 stars in 12 fields are calibrated in both ranges. One further field, Mrk 421, was calibrated, but on close examination all sources were found to be probably nonstellar; thus these results are not included here. The stars observed cover the range from V = 11 to V = 20 and from K = 9 to K = 17 and are well distributed around the sky north of declination -30°. This represents the initial sample of an extensive catalog of calibrated fields that will cover the northern sky down to declination -30° and that will cover a wide range of Galactic latitudes. These fields will be useful both for photometry of AGNs in the range from B to K and also as faint calibration standards for large telescopes. The median absolute total error on the photometry, including all known error sources, ranges from 0.008 mag in J to 0.034 mag in B. These errors will be greatly reduced with the addition of further data in the future, although the final precision is fundamentally limited by the photometric errors in the existing lists of calibration stars used to calibrate these data.

Brian Skiff has edited this table somewhat:

To make the list more useful I have omitted:

o  all stars where there nominal uncertainty in the V-band photometry
   exceeds 0.030 mag.,
o  individual remaining colors with large errors in any entry,
o  stars lacking V-band data,
o  what little U-band data is presented,
o  stars where only a single color remained after trimming observations
   with large errors,
o  most (but not all) stars observed only once on a single night, 
o  and many galaxies, pairs < 15" apart, and generally crowded stars.

This process trimmed about a third of the stars from the total
published.  

I've made a copy of the visual (BVRI) measurements in Brian's trimmed list (242 stars), changing the format slightly so that RA and Dec are in decimal degrees. You can download a copy:


Carbon stars from the Stephenson catalog

Jeff Medkeff posted to sci.astro on Oct 9, 1997:

The Stephenson catalog, which is the source of all my data, provides positions for epoch 1900 :-( for over 7000 carbon stars. I have precessed every single one to epoch 2000, thanks to a small, brute force utility I wrote in C++ (with some assistance from Mel Bartels). This whole experience was quite an adventure for me.

I have several versions available: the whole catalog in precessed form; all carbon stars in the catalog brighter than 12th magnitude (or brighter than 14th magnitude in p, if v is unknown), and all carbon stars brighter than 8th magnitude. All are still available in tab-delimited text as well as Office 97 formats. I will entertain requests for other file formats.

Anyway, the tiny amount of astronomy stuff I have on my website, including the lists of carbon stars, can be accessed at:

http://shutter.vet.ohio-state.edu/astronomy.htm

You can also download the a copy of the catalog from the TASS site:


Galactic Cepheids near the Galactic equator

Peter McCullough and Arne Henden have both mentioned the utility of monitoring Cepheids -- stars which pulse in size and luminosity with periods of a few days to a few months. The best place to go for comprehensive catalogs of Cepheid stars is the David Dunlop Observatory Database of Classical Cepheids. Here are some smaller subsets for TASS use:


Ackermann Infrared Stars

Brian Skiff has made a catalog of extremely red stars, first identified by G. Ackermann several decades ago. These stars are for the most part far from the celestial equator, so they won't appear in TASS Mark III images. They may be of interest for the Mark IV.

You may want to read a detailed description of the Ackermann catalogs by Brian Skiff.


Glenn Gombert's "master" TASS catalog

Glenn Gombert has matched TASS stars from his camera's datasets to the Hubble Guide Star Catalog. Here's his message from Mar 14, 1998:

I have just uploaded to Storm /incoming a new "Master Photometry File" that conatins ~80,000 complete with *all* of their cross-references with the Hubble Guide-Star Catalog stars. (Using a modified version of Arne's Master program to create the file). There was more work than I expexted in doing this but I think that it will prove to be very useful in the weeks ahead. The file is called "gscphot.zip".

It now gives that start of a good cross-reference TASS data with a known astronomical catalog so that cross-reference identifications can be made between data sets.(To support a variety of different projects).

In the next month or so I hope to complete the same task using the USNO A-1 catalog as well. This should serve as a good "test" of the database "seeding" using Arne's "A1" dataset that he created as the Postgress Database is populated with the same raw (starlist) data.


Takashi Ichikawa's list of M and carbon stars

Brian Skiff provides this dataset and the following explanation (posted to vsnet on 17 Apr 1998):

Appended below is a sample of a revision of the list of M and carbon stars observed by Ichikawa (1981PASJ...33..107I). Ichikawa published precise positions in _galactic_ coordinates(!), along with photographic V,I photometry and spectral types for some 750 stars in a small field in Cassiopeia.

I had more help than usual assembling this data. Jean-Claude Mermilliod (Lausanne) volunteered a few months ago to have the source data keyed-in---this alone saved me many hours of tedious work. I am extremely grateful for getting this done, all the more so since the file was delivered all but error-free! Next Larry Wasserman of the Lowell staff converted the list from galactic to equatorial coordinates, and ran a match-up of these against the USNO-A1.0 star catalogue. This produced a list with the USNO positions and the red magnitudes for stars within 15 arcsec of each Ichikawa position. These I compared individually against the source positions and photometry, and selected the entry corresponding to the correct star. Many cases were checked by looking at the b-r colors in A1.0, where the red stars are very conspicuous. Except for the last ~100 entries the stars were within about 3-5 arcsec of the A1.0 position. (The final series has a systematic offset of about -10" in RA, which very nearly = gal. long.)

The revamped list was then compared star-by-star against SIMBAD to search particularly for IRAS IDs, but also others as available. Interestingly, a few proper-motion stars appear in the list, all of which I could verify using the charts published in the Lowell Proper-Motion Survey series. In most cases the position adopted for these stars is from the GSC at epoch ~1984 (specified in the notes). A few stars were either too faint in the blue or very crowded, and so do not appear in either the GSC or A1.0. For these I estimated positions (+/- 2" or better) using the Digitized Sky Survey via the Goddard SkyView utility. The carbon and S stars were each sought in the Stephenson catalogues of these (1984PW&SO...3....1S and 1989PW&SO...3...53S). I did some comparison against the GCVS4, but the links with variable-star names may not be utterly complete.

A bunch of links within SIMBAD were found, and a list has been supplied to Gerard Jasniewicz so that they can be merged in the database.

The completed list contains equinox 2000 coordinates, the V,I photometry and types from the source, and IRAS and other IDs as appropriate. For several bright stars that were saturated on Ichikawa's plates, I have sought V magnitudes from the literature, and give these or Ichikawa's own V mags. in the notes. I should also mention that the I-band magnitudes are on the Kron system. The file (47Kb) can be obtained from the Lowell ftp site as usual:

ftp://ftp.lowell.edu/pub/bas/starcats/ichikawa.cas

Nomenclature: the SIMBAD bibliographic entry for the Ichikawa paper suggests the stars be given names of the form "Kiso M-NNN", etc. However, I must point out that the work was done entirely at the Ouda station of the Kyoto University Department of Astronomy, and has nothing to do with Kiso! The acronym should be changed either to "Ouda xxx" or perhaps "[I81] xxx", in keeping with recent definitions of such name-lists. In my file, the 722 M stars of the main list (Table 2) are simply numbered; the carbon stars from Table 3 are called "Cnn", and the two S-type stars from Table 4 are "Sn". Here's the present SIMBAD entry:

1981PASJ...33..107I
  ICHIKAWA T.
  Publ. Astron. Soc. Jap., 33, 107-133 (1981)
  The space distribution of M giants in the direction of Cas.
  Table 4: 2 S-type stars, not in SIMBAD
  Table 2:  N=722. Table 3:  N=34


Spectra of stars in the Case LF9 region

Brian Skiff provides this dataset and the following explanation (posted to vsnet on 30 May 1998):

I have completed work on obtaining positions and identifications for the Case LF 9 field in Monoceros by McCuskey (1956ApJS....2..271M). This includes 2299 stars in a 16 square degree area centered at: 6 53 20 -1 21.0 (2000), and includes some stars in the region of the open cluster NGC 2301. The revised list, as before, includes GSC positions and identifications, HD/BD/SBD names, along with the photo-blue magnitudes (rounded to 0.1 mag. precision) and spectral types from the source paper.

Again the re-reduced AC zone catalogues were helpful in dealing with close pairs that are merged in the GSC but omittetd from Tycho/ACT. (Thanks to Francois Ochsenbein and gang for adding these to the VizieR Web site.) In addition, I have compared the list against the BD identifications of R. Bonnet (1979BICDS..16....7B), the overlapping region of LF 11 by Wooden (1970AJ.....75..324W), and with the Landolt stars of SA 98.

A number of IDs and corrections for SIMBAD have been supplied to (and mostly already fixed by) Gerard Jasniewicz. The complete file (150Kb) is posted at the Lowell ftp site:

ftp://ftp.lowell.edu/pub/bas/starcats/lf9.fil


New variables discovered by K. Takamizawa

Taichi Kato posted this message to VSNET on Aug 25, 1998:

We have compiled a list of new variable stars discovered by K. Takamizawa, and posted to vsnet-obs. ftp://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/others/TmzV/newvar.cat

The listed will be updated with the incoming data. We would be extremely happy if we can future include new (and previously discovered) variable stars and candidates from anyone interested.


New variables discovered by the MISAO project

The MISAO Project tracks information on astronomical objects of all kinds. They have discovered a number of variable stars. You can find their list at their WWW site:


  http://www.info.waseda.ac.jp/muraoka/members/seiichi/misao/data/misv.cgi?en


New variables discovered by Haseda

The MISAO Project tracks information on astronomical objects of all kinds. They have a list of stars discovered by Katsumi Haseda at their site. You can read it at


http://www.info.waseda.ac.jp/muraoka/members/seiichi/misao/public/HadV.lst


Wachman Variables from the Cygnus starcloud

Brian Skiff posted this message Feb 9, 1999:

Here is a list of accurate coordinates and identifications for about 65 variables in the southern Cygnus starcloud observed by Wachmann. Most of these stars are listed in SIMBAD with only semi-accurate coordinates. I used the GSC and A2.0 catalogues along with Wachmann's excellent charts to make the identifications.

The first part of the table gives the new variables found by Wachmann, followed by known ones he studied. In the first column is the designation given by Wachmann, and the second column gives the GCVS name. Equinox 2000 positions follow, along with GSC names as available. Column 's' shows the source of the coordinates: G = GSC v1.1, A = USNO-A2.0. The Remarks column shows other names if they are "new", i.e. not linked in the same SIMBAD entry.

There are several more surveys by Wachmann in the late volumes of the Hamburg Abhandlungen, which I will try to work on soon.

source:  1961AAHam...6....1W
         Wachmann A.A.
         Astron. Abh. Hamburg. Sternw., 6, 1-96 (1961)
         Die veranderlichen im sudteil der Cygnuswolke.

I reformatted the table into decimal degrees for RA and Dec, and replaced spaces in star names with underscores.
MWR 3/5/1999


Wachman Variables from SA 98

Brian Skiff posted this message Feb 16, 1999:

Wachmann's first paper on his variable star survey in the region of Selected Area 98 is a trivial one to fix, since he provides positions at arcsecond precision. I used the list-searching capability of the Strasbourg VizieR utility to compare Wachmann's coordinates with the GSC and USNO-A2.0. The positional differences with these sources ranged from about 2" to 10", so the positions below represent a modest improvement over the original ones. I checked all the cases where the VizieR match-up yielded an offset of more than ~2" via charts, DSS images, magnitudes. Additional "new" IDs were made using SIMBAD.

I reformatted the table into decimal degrees for RA and Dec, and replaced spaces in star names with underscores.
MWR 3/5/1999


Chavira Infrared variables

Brian Skiff posted this message Feb 28, 1999:

After a fair bit of work I have obtained accurate positions for all but two of the "infrared stars" listed by Chavira in a 1967 paper based on far-red direct and objective-prism plates. The main difficulty in the identifications was the poor published positions, some in error by 10' or more. The finder charts were thus indispensable for positive identification on the sky.

Chavira gives Johnson I-band magnitudes and spectral types for most of the stars. Along with coordinates, I have added here IRAS identifications as well as USNO-A2.0 magnitudes and colors (if available) to provide some idea of their brightness in the visible. Note that the red magnitudes for these stars are typically between mag. 13 and 15---not extraordinarily faint. A few of the stars are known variables, but all certainly are to some degree.

The first seven "Haro-Chavira" stars were published by Johnson et al. in a 1965 ApJ paper (HC 5 is missing from the list), which includes BVRIJHKLMN (!) photometry. The positions listed for these stars are consistently nearly a full degree in error! This seems to be due to application of 100 years of precession in the wrong direction. I'm guessing that the BD (equinox 1855) was used to estimate the positions, then precessed to 1950 for publication; the error resulted in positions that seem to be about right for 1750 instead. It was only by chance that I noticed a star pattern from one of the finder charts on the POSS-I prints, which allowed me to find the others using the same offset.

I reformatted the table into decimal degrees for RA and Dec, and replaced spaces in star names with underscores.
MWR 3/6/1999


Hoffmeister suspected variable stars

Brian Skiff posted this message Mar 3, 1999:

The list below gives accurate coordinates for some 290 designated and suspected variables in several fields described by Hoffmeister in a 1963 paper. Many of the NSV stars in the "iota CMa" field below have been dealt with previously by Lopez in IBVS 3873, which gives coordinates for some southern NSV stars. A few stars defeated my attempts to identify them. Given that some of the stars I did find have positions as much as 10' in error, it is likely that these "lost" ones have gross errors of some kind.

The format of the table is much the same as previously, although I've given a bit more space in the first two columns to accomodate names. The stars are given in groups as per the unnumbered tables in the source paper. An asterisk by the GCVS name indicates a note at the bottom of the table. Column 's' is the source of the position: A = USNO-A2.0, S = SkyView DSS frame, T = ACT. I made the match-up with the GSC using VizieR, and found the various IDs in the Remarks using SIMBAD. The IDs are listed only if they are "new", defined as being either not present or not linked in the same entry in SIMBAD.

I reformatted the table into decimal degrees for RA and Dec, and replaced spaces in star names with underscores.
MWR 3/6/1999


Gareth Williams' catalog of accurate positions for variable stars

Brian Skiff posted this message Mar 4, 1999:

My thanks to Kato-san for adding Gareth ("Graff") Williams' comprehensive coordinates file to the VSNET archives. This represents a tremendous amount of work on Graff's part over the last several years, and I hope this will greatly ease the burden of the Sternberg group improving the positions for GCVS stars. Having worked with Graff both on asteroid astrometry and on variable-star identifications (see IBVS 4448-4451), I know that he is pretty picky about getting things right. Thus although he is an error-prone human like the rest of us, the list is probably about as good as man and machine can contrive to produce.

Some additional words are in order about the file. Those who have downloaded the file have noticed the format is very wide, which was necessary to accomodate everything on a single line per star. As best I can tell it is 170 columns wide. Graff is used to working with a 220-column format for asteroid orbits, so this one is comparatively narrow!

One of the big conveniences of the file is that citations are given for the source charts. (Not in the version stored here! MWR) As part of our correspondence about the file, Graff sent me a list of papers for which he has done a complete job, and those for which only some of the stars were worked over. I append this below directly from his messages. (Having to deal with hundreds of thousands of asteroid observations every month forces Graff to be well-organized!) These are papers that for the most part don't need to be dealt with---and tells us what still needs work. Given that he's buried in astrometry from the major asteroid surveys, additional lists of variables from him will probably be slow in coming, so this may be regarded as complete. Graff did tell me that if he gets more positions, he will pass them along to us.

I reformatted the table into decimal degrees for RA and Dec, removed all references (yikes!) replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs. The file now has a width of 80 characters.
MWR 3/6/1999


Westerlund M giants

Brian Skiff posted this message Mar 10, 1999:

As part of work identifying variables in Aquila, I have gone over an early list of mine that provides coordinates and IDs for 478 M giants found on far-red plates by Westerlund in the Case LF1 region. The coordinates were originally obtained by measuring photocopies of the source charts on our PDS machine together with PPM stars as were available (about a dozen per field). This yielded positions good to some arcseconds, from which I tried to make IRAS IDs. It was not convenient at the time (and still isn't!) to examine the POSS-I and POSS-II plates to verify the identification of each as a red star; the USNO-A catalogues had not been built at that time (1994). Thus some uncertainty remained about the results. Westerlund's charts are none too clear, so this has not helped.

I have now checked the list against sky-survey images in doubtful cases, and have replaced the positions with those on the ICRS as far as possible. This leads to minor changes (less than 3") in most cases simply from the different catalogues used. In a number of cases the stars have been positively identified for the first time and substantial changes (in the 15"-30" range) have been made. I have matched the list anew against the GCVS, IRAS, and ACT using VizieR. There are still some ambiguous cases, given the Notes.

Column 's' gives the source of the positions as follows: A = USNO-A2.0, G = GSC v1.2 (not v1.1), S = SkyView (+/- 2"), T = ACT. The column 'mi' shows the infrared (roughly I band) magnitude estimates made by Westerlund. All the stars will be variable to some degree of course. For instance, while verifying the location of LF 1 B 132, by comparing the POSS-I and POSS-II images it was easy to discern that it has a full amplitude of at least 2 magnitudes in the red.

All the stars were added to SIMBAD using the original "soft" positions by Francois Ochsenbein during my summer 1995 visit to the CDS-Strasbourg. The data in this revision should be much more reliable. A sample of the list is shown below; the complete version (35Kb) is at:

ftp://ftp.lowell.edu/pub/bas/starcats/lf1ir.fil

Among other things, the list will help nail down variables appearing in at least two lists by Hoffmeister (AN 288 and 289) in these incredibly crowded star fields.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 3/21/1999


Hoffmeister S8014-8097 catalog

Brian Skiff posted this message Mar 19, 1999:

Here is the first part of identifications for variables appearing in an extensive list by Hoffmeister (1964 AN 288,49). The format is identical previous lists of mine. Most of the stars were fairly easy to identify, although two (S 8047 and 8050) seem to be not near their nominal locations.

Most of the remainder of the stars in this paper (520 variables total) lie in crowded Milky Way fields, and will take some work to identify correctly.

source:  1964AN....288...49H
         HOFFMEISTER C.
         Astron. Nachr., 288, 49-68 (1964)
         Mitteilungen uber neuentdeckte veranderliche Sterne.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 3/21/1999


Hoffmeister S8247-8534 catalog

Brian Skiff posted this message Mar 21, 1999:

Here are accurate coordinates and identifications for the remainder of the variables from 1964AN....288...49H that are _not_ in the three densely crowded Milky Way fields (gamma Aql, gamma Sge, and rho Cyg regions). The format is the same as previously.

source:  1964AN....288...49H
         HOFFMEISTER C.
         Astron. Nachr., 288, 49-68 (1964)
         Mitteilungen uber neuentdeckte veranderliche Sterne.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 3/21/1999


Hoffmeister S8375-8429 catalog

Brian Skiff posted this message Mar 22, 1999:

Another batch from the Hoffmeister AN 288,49 paper. My powers of pattern recognition seem to have worked well in this field (the rho Cyg region).

source:  1964AN....288...49H
         HOFFMEISTER C.
         Astron. Nachr., 288, 49-68 (1964)
         Mitteilungen uber neuentdeckte veranderliche Sterne.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 5/24/1999


All stars from the Hoffmeister 1964 AN paper

Brian Skiff posted this message May 30, 1999:

I have completed work on identifications for the Hoffmeister survey published in 1964 AN 288,49, totalling some 520 variables. The two crowded fields surrounding gamma Aql and gamma Sge were tough work, yet all but three of the stars were recovered. Rather than send these two fields out, I have simply copied the complete list to the Lowell ftp area:

ftp://ftp.lowell.edu/pub/bas/starcats/hoff3.lis

source:  1964AN....288...49H
         HOFFMEISTER C.
         Astron. Nachr., 288, 49-68 (1964)
         Mitteilungen uber neuentdeckte veranderliche Sterne.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 5/30/1999


Stars from Hoffmeister 1966 AN 289 paper

Brian Skiff posted this message June 13, 1999:

Here are additional accurate positions and identifications for the first several fields of the next batch of Hoffmeister variables. The format is identical to previous lists in this series. A few of these stars already have precise positions published by Shokin & Samus (IBVS 4429) and by Williams & Skiff (IBVS 4451).

source:  1966AN....289....1H
         HOFFMEISTER C.
         Astron. Nachr., 289, 1-21 (1966)
         Mitteilungen uber neuentdeckte veranderliche Sterne.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 6/13/1999


Carbon Stars from Soyano and Maehara

Brian Skiff posted this message November 9, 1999:

In the latest issue of the Publications of the National Astronnomical Observatory of Japan, Soyano and Maehara present their seventh (and final) list of carbon stars in the northern Milky Way. Below I have extracted the sixty-four stars not already in the 1989 Stephenson carbon-star catalogue (a few CGCS objects were overlooked by the authors) and show improved equinox 2000 positions and other IDs. Using the Strasbourg VizieR utility, I compared the list against the GSC-ACT, USNO-A2.0, the IRAS point-source catalogue, and the GCVS 4.1/NSV/NSVS.

Most of the stars appear in either the GSC or USNO-A, but some are evidently too faint in the blue, and so are not in either catalogue, and I retain Soyano & Maehara's original (SAO-based) positions precessed to equinox 2000. A few positions for variables found by Dahlmark were extracted from Graff Williams' and my lists of precise positions for the LD variables. The source of the position is given in column 's', coded as indicated below.

The V magnitudes are copied from the source list. I will note that the USNO-A red magnitudes for the stars are typically between 11 and 13: these are fairly easy targets for those with modest equipment (and sky patrol projects) to look for variability.

By analogy with previous lists, the names for these objects should be given in the form "Kiso C7-xxx".

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 11/9/1999


Graham standards in the southern Harvard E regions

Brian Skiff posted this message to VSNET, Sep 2, 2002:

The lists below show accurate coordinates and identifications for the Graham standard stars in the southern Harvard E regions. Complete data are also copied from the original paper. In follow-up work, Joner & Taylor show that Graham's data systematically match the original Cousins E-region system with moderately large per-star scatter. They also provide additional VRI observations of about three dozen of the brighter stars. These data are shown in the second table.

In both tables V-I has been derived from the simple sum of V-R and R-I, and errors calculated from their errors taken in quadrature. All errors shown are mean errors of the mean. An asterisk by the star name indicates a note at the bottom of the first table. These mostly NSV names for suspected variables. The Joner & Taylor data show that many of these probably are not variable.

The fainter groups of Graham stars usually fall in fairly small fields (~10' across) so they can be observed with common CCD set-ups. As with other such lists, it is best to choose stars with "many" observations and small internal errors, and in this case those with confirming observations by Joner & Taylor should be favored.

I reformatted the table into decimal degrees for RA and Dec, replaced spaces in star names with underscores, and put entries of "0" to denote no cross-ID in the other catalogs.
MWR 9/2/2002


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