[vsnet-chart 345] AY Dra chart

["Ondrej Pejcha" <opejcha@volny.cz>]

Dear All,

I have prepared a standard MEDUZA chart of AY Dra including
also CK Dra, btw. It is based on old MEDUZA chart (TYC,
TYC-2, GSC), Sumner sequence, Henden field photometry and
one star measured from CCD V band images by L. Smelcer.
   I extended the Sumner's sequence down to 17.7 mag; I hope
AY Dra won't fade below this value. The accuracy of Henden's
photometry lowers to ~0.05 mag when stars are fainter mag
16. However, this shouldn't affect visual estimates, CCD
observers are then advised to use brighter stars as the
reference ones.
   The only star from images by L. Smelcer should have error
lower than 0.05 mag (if not extremely colored). Values of
GSC mags in this area are accurate to 0.1 mag (with respect
to standard V mags).

Various versions of the chart are available through
http://var.astro.cz/pejcha/aydra/

Best regards and good observing

Ondrej Pejcha

P.S.: I forgot, due to compatibility with older versions,
the MEDUZA chart does not include a bright star about 2'
northeast from AY Dra (ie GSC 3872 802), which was measured
to have
V = 11.552 +- 0.016 mag
B-V = 0.681 +- 0.008 mag

This star is extremely suitable for CCD photometry as it is
very close to variable.

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp