Re: photometric vs. non-photometric

[andrew.bennett@ns.sympatico.ca (Andrew Bennett)]

On Thu, 9 Sep 1999 09:33:13 -0400, Stupendous Man
<richmond@A188-L009.RIT.EDU> wrote:

> ...
>  I know that the TASS database contains many "spurious pairs",
>sets of stars which are really instances of the same celestial object,
>but which appear as separate entities in the database.  I believe
>that some of the objects Andrew mentioned, which appear only a few
>times in the midst of a field with stars detected many times,
>may be members of such spurious pairs.

TN056: 26,000 close pairs vs 346,000 V-band measurements.
Less than 10% even before you purged them. I don't think
this can produce the drastic scatter observed.

Consider a chunk of sky covered on average 25 times.
Assume the coverage completely random.
Then 99.9% of the time, one would expect the actual
coverage for a particular star to lie between 10 and
40. Most of the time between 20 and 30. The actual
distribution is quite different. Remember, this is
brightish stars - probability of detection about unity.

Of course, this could simply be the result of the
coverage being non-random. But as nobody seems to
know where their cameras were pointing, this is
not easy to test ...

Andrew Bennett, Avondale Vineyard, Nova Scotia, Canada.