BN Peg (was Re: Magnitude range of images)

["Dirk Terrell" <terrell@boulder.swri.edu>]

On Mon, 22 Oct 2001 13:18:13 -0400, Stupendous Man wrote:

>  An executive summary might be that for exposures of 50 second
>in Batavia, photometry reaches the +/- 5% point around V = 12.5, 
>and saturation occurs around V = 8.0, I = 7.5.

Ok, thanks for those pointers Michael. After reading through those
three tech notes, I have a much better feel for what the setup can do.
The most promising eclipsing binary candidate for getting something out
of these recent images is BN Peg, a 0.71 day EB with V=10.3 to 11.2
(spectral type is around F5, Popper says F5 - F8) that is probably a
near-contact binary at 21h28m02s +5 00'. (2000). Looks like Tom got it
on two nights: 9/27 and 10/6. Depending on when he started on the 27th,
he might have gotten a secondary eclipse. But if it really is
near-contact, then there will be variation all through the cycle. Not
much published on this one, so it's worth looking at it. If the
ephemeris I have is any good, there will be a primary eclipse tomorrow
evening. The table below shows the UT times of primary minimum over the
next 10 days if we can hit this field and get that eclipse. 

Dates for the occurrence of phase: 0.0000

 2452205.2989 22 Oct 2001 19.17 UT (19H 10M 24S)
 2452206.0122 23 Oct 2001 12.29 UT (12H 17M 33S)
*2452206.7255 24 Oct 2001  5.41 UT ( 5H 24M 41S)
 2452207.4388 24 Oct 2001 22.53 UT (22H 31M 50S)
 2452208.1521 25 Oct 2001 15.65 UT (15H 38M 59S)
 2452208.8654 26 Oct 2001  8.77 UT ( 8H 46M  8S)
*2452209.5787 27 Oct 2001  1.89 UT ( 1H 53M 17S)
 2452210.2920 27 Oct 2001 19.01 UT (19H  0M 26S)
 2452211.0053 28 Oct 2001 12.13 UT (12H  7M 35S)
*2452211.7186 29 Oct 2001  5.25 UT ( 5H 14M 44S)
 2452212.4319 29 Oct 2001 22.36 UT (22H 21M 53S)
 2452213.1452 30 Oct 2001 15.48 UT (15H 29M  2S)
 2452213.8585 31 Oct 2001  8.60 UT ( 8H 36M 11S)
*2452214.5718 01 Nov 2001  1.72 UT ( 1H 43M 20S)

Dirk