For examples of TASS Mark IV data, check out the Mark IV Sample Data page.
Mike Salmon has put a copy of a whole CD-Rom's worth of Mark IV images taken by Tom Droege onto his FTP site (which is in the UK, so access might be slow for people across the Atlantic):
http://www.cru.uea.ac.uk/tassThe images are in FITS format, not GIF or JPEG -- so you'll have to use an astronomical image processing program to view them. One possibility is FITSVIEW
Mike Gutzwiller has created a WWW page with information on variable stars he's found in the TASS dataset. See http://home.fuse.net/deepsky/TASS_Variables.htm for Mike G.'s list.
This page contains miscellaneous examples of image, plots, and numbers derived from the TASS Mark III cameras. It may change without warning.
In the plot below, TASS V-band measurements of X Ceti are compared to visual measurements from the VSOLJ (Variable Star Observing League of Japan). Note the close correspondence; the only difference is at minimum light.
Glenn Gombert has found a number of new variable stars in the Mark III dataset. Below is a plot of the light curve of one. Glenn says (Nov 16, 1998):
Attached is the "I" band light-curve of a new semi-regular variable at the above mentioned coordinates. This is a star that Michael had one period of on his AAS poster paper and I think now it has been determined as a new semi-regular that two periods of the star have been recorded. Thanks to Brian Skiff as well for taking time to look at and review the data. I think that we have just started to explore what may be found in all of the TASS data that has been collected and re-reduced so far...
Glenn Gombert discovered that the star BD -02 5436, which was not known to vary, actually has a period of about 105 days. His plot appears below, and he has submitted a report to the IBVS.
The known variable TW Aqr is just a short distance away from BD -02 5436 -- see its light curve in the next section.
The light curve of BD -02 5436 is clearly periodic in V-band, but the I-band measurements show much less regular behavior.
Since TW Aqr is just a short distance from BD -02 5436, some people suggested that Glenn may have confused the two stars. But, as you can see below, its light curve in V isn't very similar, and it is about 2 magnitudes brighter, too.
Glenn noticed the variability of this star, and sent me E-mail about it on May 19, 1999. I looked up its position
RA = 306.9664 Dec = -1.8233 (J2000)
in
Simbad,
and found two matches:
IRAS 20252-0159 and StM 519.
Here's the data from Simbad on the object:
ICRS 2000.0 coordinates 20 27 52.0 -01 49 24 D ~ FK4 1950.0/1950.0 coordinates 20 25 16.4 -01 59 22 Galactic coordinates 42.75 -22.20 V magn 13.5 Spectral type M7:and the data from IRAS:
IRAS : ra, dec (1950) f12 f25 f60 f100
-----------------------------------------------------------------------
20 25 16.4 -01 59 22 3.96 1.61 .40L 1.00L
The "StM 519" is a reference to the catalog of late M stars found in an objective-prism survey by C. B. Stephenson, ApJ 301, 927 (1986). Note the last sentence of Stephenson's abstract:
Although difficult to quantify, it appears unlikely that large numbers of these late M stars are undiscovered variables of appreciable amplitude.
Well, he was wrong about this one, I guess.
Glenn noticed the variability of this star, and sent me E-mail about it on May 23, 1999. I looked up its position
RA = 316.0236 Dec = -2.0453 (J2000)
in
Simbad,
and found the following synonyms:
TW Aqr, GCRV 13235, IRAS 21015-0214.
Here's some of the data from Simbad on the object:
ICRS 2000.0 coordinates 21 04 05.5 -02 02 44 D ~ FK4 1950.0/1950.0 coordinates 21 01 30.0 -02 14 41 Galactic coordinates 47.51 -30.19 V magn 11.8 Spectral type M6The General Catalog of Variable Stars states the following:
vartyp Vmax p Vmin period (d) epoch (JD) Reference ---------------------------------------------------------------------- SR 11.80 V 12.80 1971GCVS3.C......0K
The IRAS satellite measured the following IR fluxes:
IRAS : ra, dec (1950) f12 f25 f60 f100 ----------------------------------------------------------------------- 21 01 30.0 -02 14 41 1.00 .55 .40L 1.00L
Here are the TASS measurements -- they agree with the V-band limits in the GCVS, and also show the lack of a strict period.
Glenn noticed the variability of this star, and sent me E-mail about it on May 25, 1999. I looked up its position
RA = 322.3324 Dec = -2.2349 (J2000)
in Simbad, but found no match. This is apparently a star with no prior
known variable behavior. I don't understand the light curve shown below
myself.
Glenn noticed the variability of this star, and sent me E-mail about it on June 5, 1999. I looked up its position
RA = 310.5940 Dec = -2.9117 (J2000)
in Simbad, and found two matches:
name RA (J2000) Dec ------------------------------------------------------------------- PPM 708599 | *| 20 42 22.54 -02 54 42.4 | IRAS 20397-0305 | IR| 20 42 22.4 -02 54 44 |The IRAS measurements in the infrared are (flux, in milliJanskys, in the four IRAS passbands):
12 mu 25 mu 60 mu 100 mu
-------------------------------------------
2.47 1.07 .40L 1.00L|
Mike Gutzwiller noticed the possible variability of this star, and sent E-mail to the TASS mailing list on June 14, 1999. He sees a couple of possible eclipses in data from his triplet. The star is at
RA = 11.5629 Dec = -0.0391 (J2000)
Simbad shows one match: PPM 701090, at
RA = 0h 46m 15.139s Dec = -00d 02m 19.34s
The only information listed is a V magnitude of 10.0, and the proper motion.
