[vsnet-alert 3938] GSC 6875.01922 - a mystery object

[Mati Morel <morel@ozemail.com.au>]

        While working on a new chart for the Mira variable TY Sgr, I have
stumbled on
the star GSC 6875.01922, for which the following data is available :

RA (2000)   DEC (2000)   Mag.   Source    Date of Observation   Plate
============================================================================
19:18:05.15  -23:50:01.9  11.7R  USNO-A2.0 1951 Aug. 11  
                          11.7B  USNO-A2.0 1951 Aug. 11
19:18:05.26  -23:50:01.5  13.85  GSC       1976 May 27           J2336
                         ~17.5   DSS        ?  ?
        On the face of it, we would seem to have a new, large amplitude variable
on our hands. Its DSS image is somewhat fuzzy, and my estimate is based on
USNO-A2.0
mags for some nearby stars. The nearest established sequence is that used by the
VSS, RASNZ for TY Sgr, about 8' to the SW. The visual mags have been in use for
about 40 years, and a comparison with GSC mags reveals close agreement in most 
cases. So, the GSC value of 13.85 would not be too far out, I would expect.
        I have looked for this object in as many different places as possible,
from recent catalogues and namelists of variables, to other types of objects
such
as lists of symbiotic stars, red stars (carbon stars), Wolf-Rayet stars,
IRAS etc.
Nothing. Zilch. The really amazing observation is from the DSS image. As
mentioned
earlier, the object's image seemed faint _and_ fuzzy. By using PaintShopPro
I sharpened
up the image. Generally, this improved the sharpness of the images of stars down
to 17mag. GSC 6875.01922 was hardly changed - still fairly soft. I mention
this as it
may be a clue to its nature. Maybe it's a small nebula. PN?  I have come
across some
faint galaxies in the GSC which have greatly exaggerated mags, but this one
would be
stretching credibility beyond limits.
        This may be an object worth looking at in the coming season, to get some
idea of its current brightness, and color information. I won't speculate on the
possible nature of the beast. What we need are observations. Any takers?  Unless
someone can identify the thing sooner.
Regards,   
/Mati

  /=====================================\
  |  MOREL ASTROGRAPHICS                |
  |  Stellar Data & Information Centre  |
  |  c/o M. Morel                       |
  |  6 Blakewell Road,                  |
  |  Thornton  NSW 2322  AUSTRALIA      |
  |  Tel./fax: (02) 4966 2078                                   |
  |  151d38'33" E, 32d46'47"S           |
  |  e-mail: morel@ozemail.com.au       |
  \=====================================/

VSNET Home Page

Return to Daisaku Nogami

---

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