Description of high-quality color subset of TASS tenxcat catalog

Michael Richmond
Oct 14, 1999

For more information on the TASS Mark III project, see the TASS home page at http://stupendous.rit.edu/tass/tass.shtml

For more information on the tenxcat catalog, see TASS Technical Note 56 at http://stupendous.rit.edu/tass/technotes/tn0056.html

The "high-quality color subset" of tenxcat differs from the regular tenxcat in the following ways:

• each star must have been observed at least 5 times in V-band, and
• must have been observed at least 5 times in I-band, and
• must have sigma(V) <= 0.20 mag, and
• must have sigma(I) <= 0.20 mag

The "high-quality color subset" of tenxcat should contain

• 117,503 lines
• 15,337,927 characters

     0001-00381 00:00:00.2 +01:05:20  9.13  0.05  15  0.30  0.05   4  0.56  0.06  28 0 0 0                                        

235959.7-000355 23:59:59.8 -00:03:55 10.36  0.03  17  0.66  0.06   5  1.36  0.04  38 0 0 0                                        

The gzip'd version of the file should have 2,738,050 characters.

Description of each field in the "high-quality color" subset of tenxcat

Fld#	Field name	Type	Description
1	name	string A15	This is usually the ID of the star in the GSC version 1.1: 0323-00222 but, if there is no matching GSC star, a name in the spirit of the proper IAU designation which looks like this: HHMMSS.s+DDMMSS In order to make this last name into a real IAU designation, one must add the prefix "TASS J"; for example, TASS J023553.2-020325
2	ra	string A10	The Right Ascension in sexigesimal notation: HH:MM:SS.s
3	dec	string A9	The Declination in sexigesimal notation: +DD:MM:SS
4	vmag	float F5.2	The V-band magnitude. This value is an unweighted average of the measurements in all detections of the star.
5	vsig	float F5.2	The standard deviation from the mean V-band magnitude.
6	nv	int I3	The number of detections in V-band.
7	V-R color	float F5.2	The (V-R) color. A blank value means no data in either V or R, or both.
8	V-R sigma	float F5.2	The standard deviation of the (V-R) color, based on the uncertainties in the V and R magnitudes. A blank value means no data. When only a single R-band measurement exists, it is assumed to contribute exactly 0.10 mag to the uncertainty in the (V-R) color.
9	nr	int I3	The number of detections in R-band.
10	V-I color	float F5.2	The (V-I) color of the star.
11	V-I sigma	float F5.2	The standard deviation from the mean (V-I) color, based on the uncertainties in the V and I measurements.
12	ni	int I3	The number of detections in I-band.
13	flags	3 ints 3 * I1	This field contains three values, each a single digit, either "1" or "0"; they denote the "raw_flag", "flag2" and "flag3" values. See a detailed explanation below.
14	ac2000_id	int I7	The ID of the matching star in the Astrographic Catalogue 2000, which is being constructed by the US Naval Observatory. Actually, this ID was taken from the ACT catalog, a prequel to the AC2000. If there is no matching ACT star, the field is NULL.
15	hd_id	int I6	The ID of the matching star in the Henry Draper Catalogue. Actually, this ID was taken from the ACT catalog. If there is no matching HD star, the field is NULL.
16	spectype	string A4	The spectral type of the star, from the Henry Draper Catalogue. If there is no matching HD star, this field is NULL.
17	iras_id	string A12	The name of a matching source in the IRAS Point Source Catalogue. If there is no matching IRAS source, this field is NULL.

Here is a detailed description of the flags encoded in field 13. The field contains three single-digit values, in which each digit is either '0' or '1'.

• The first digit shows raw_flag:
  • '0' means that the magnitudes were corrected for color terms;
  • '1' means that they were not corrected, usually because a (V-I) color could not be determined.
• The second digit shows flag2:
  • '1' means that it was a member of a spurious pair (see below), but has been merged together with its spurious companion.
  • '0' means that the star was not part of a spurious pair which was merged.
• The third digit shows flag3:
  • '1' means that it was a member of a spurious pair, and was unable to be merged together with its spurious companion. In this case, another entry will exist in tenxcat for the spurious companion.
  • '0' means that the star is not part of spurious pair which could not be merged.

Some examples:

• 0 0 0 The star's magnitudes have been corrected for color terms. It was not a member of a spurious pair.
• 1 0 0 The star's magnitude have not been corrected for color terms. It was not a member of a spurious pair.
• 0 1 0 The star's magnitudes have been corrected for color terms. The star was a member of a spurious pair, but the two entries have been merged. All data on the two members appears combined in this entry.
• 1 0 1 The star's magnitudes have not been corrected for color terms. The star was a member of a spurious pair, and it was impossible to merge them. An entry for the other member of this spurious pair will appear elsewhere in tenxcat. It, too, will have a value of '1' in the final character of this flag field.