[vsnet-chat 126] Re: U Gem - bad comparsion

[Taichi Kato <tkato>]

Rudolf Novak wrote (vsnet-chat 123):

> could someone help me with good comparsion stars to U Gem? I've just look
> at the star using GSC magnitudes and there were certainly some mistakes
> with my map. Star marked as 9.0 was BRIGHTER then the star 8.8
> I know that GSC has some errors but is this possible? And is there some
> chart for visual observers on VSNET or some other HP? (AAVSO,...,?)

   I think most U Gem observers use the following three stars at maximum.
Your magnitudes are different from those on GSC 1.0.  Have they been revised,
or your chart viewer uses SAO mags for bright stars?

   R.A.     Decl.            GSC mag   SAO mag/sp  HIC V/B-V
----------------------------------------------------------------
075508.60 +214016.4 (2000.0)  8.6        8.5 A     8.62 +0.33
075623.47 +215011.1 (2000.0)  9.1        9.0 G
075631.34 +215231.1 (2000.0)  8.4        8.8 A                 = NSV 03816

   At least the first star may be used safely for comparison.

   The VSNET ftp chart archive indeed has a sequence for U Gem but this
small area only covers fainter than mag 11 - thus may be used when the
star becomes faint.

Regards,
Taichi Kato

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