THIS IS THE TASSBETA README AND DESCRIPTION FILE AND SHOULD BE STORED

tassbeta.dat consists of over 380,000 TASS V and Ic measures.

The data is courtesy of Tom Droege, taken on his own self made cameras, and
the reference to the online database is

http://sallman.tass-survey.org/servlet/markiv/

which is the reference to be used when measures are used.

Positions are good to the arcsec or better.

The V and Ic measures are averages of observations of at least ten and often
far more V and Ic observations and the individual V and Ic observations are
made simultaneously.  Individual observations can be downloaded and plots of
them examined at the above reference url.

This particular list has been filtered in the hope of providing good quality
V measures of standard stars.  V-Ic is also included to help with colour
determination.

This is a beta catalogue, and as such a problem with preceding zeros in the
sexagesimal position has not been resolved, although column integrity has
been maintained.  This can lead to declinations 
like -00 being written as - 0 for example.

The Welch Stetson index is a means of assessing variation and variability in
a data set of two colour photometry.  Negative values show problematic
photometry.  Large values show variability if observations are large, and
either star variability or data variation if less large values.  This data
set has been truncated at WS index values of 10 or less.  WS indices of 50 or
more are likely variables, when there are no data problems.  The lower the WS
index value the more likely there is no variation in the data.  Assessment of WS
index in relation to TASS data is still ongoing, and on occasion values of 9
may be better than values of 0.1.  Clues and evidence on this is part of the
beta test objectives.  Assessment of WS index use in this could lead to
either more strict limits, eg WS index <5 or lower, giving better quality data, or
if alternatively most data with WS index < 10 was in fact of use and of usually
good quality, the level may be increased to eg 20, thus allowing far more
stars in the catalogue.


COLUMNS

1 RA hours

2 RA minutes

3 RA seconds

4 Dec degrees

5 Dec minutes

6 Dec seconds

7 RA in decimal degrees (for use with TASS database interface, to check plots)

8 Dec in decimal degrees (for use with TASS database interface, to check plots)

9 Johnson V magnitude, given to 3 decimals so the user can decide on rounding
The mean V magnitude from all measures of V

10 Error in V.  Errors are root mean square means of each observational error
and are _not_ standard deviations of all observations

11 Cousins Ic magnitude, given to 3 decimals so the user can decide on rounding
The mean Ic magnitude from all measures of Ic

12 Error in Ic.  Errors are root mean square means of each observational error
and are _not_ standard deviations of all means

13 V-Ic.  Colour (use Pickles' table for conversions)

14 Error on V-Ic.  Calculated by square_root(meanV^2 + meanIc^2)

15 The number of observations that went in to the mean V and Ic values

16 How many nights the observations of V and Ic were taken over

17 The Welch-Stetson Index (an indicator of variation and variability)



Data is courtesy of Tom Droege's observations, as processed by Michael
Richmond's pipeline (www.tass-survey.org and links thereunder).

J Greaves