Re: [TASS] photometric vs. non-photometric

[Chris Albertson <calbertson@LOGICON.COM>]

Andrew Bennett wrote:
>

> ... Otherwise one knows nothing about
> what somebody decided to throw away. A lot of the gaps in
> tenxcat are like this: was a star below some limiting
> magnitude (oops - I mean above; you optical types measure
> backwards) or was it not measured. It makes a big difference
> to the statistics.

It is always hard to answer the question "why is something NOT
here?".  For the tenxcat list it helps to know that it is intended
to be a subset of the "real" TASS catalog.  It contains only the
stars that by Michael's criteria have "good data".  There is another
table in the database the "tass catalog" that contains _all_ stars
seen by TASS.  So if the star is not in tenxcat but IS in the
tass_catalog it is due to a decision by the author of tenxcat.

If the star is in an area of the sky that was covered by the survey
and it is not in the tass_catalog then it must have been below
TASS' detection limit for any of a number of reasons.  To dim,
to bright, to close to another star, bad luck with clouds, and
so on.

There is lots of raw data to look at.  I think it you asked you could
get a reasonable sized sample.  I would imagine that by now the total
raw FITS image data is in the tens of gigabytes.
>
> Andrew Bennett, Avondale Vineyard, Nova Scotia, Canada.

--
  Chris Albertson

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