[vsnet-alert 21424] Re: PNV J20205397+2508145: new transient (12.3 mag) in Vulpecula

[Brian Skiff]

On Tue, 2017-09-12 at 18:25 +0000, Patrick Schmeer
pasc1312-aavso at yahoo.de via vsnet-alert wrote:
> PNV J20205397+2508145  (CV:)
> 
> RA 20h20m53.97s, DEC +25°08'14.5" (J2000.0)
> 2017 Sept. 12.5422 UT, 12.3 mag; 12.67 UT, 12.7 mag
> (both CCD, unfiltered).
> Discoverer: Tadashi Kojima, Gunma-ken, Japan

> Five Gaia DR1 sources in the 18-21 mag range
> are within 6 arcsec of the transient's position.
> Precise astrometry, spectroscopy and time-resolved
> photometry are urgently required.


     Possibly a long shot, but I notice one of the faint stars
close to the nominal position is very blue.  It is visible
only on the blue plates from POSS-I and POSS-II.

GSC2.3 N32C046859:  20 20 54.39 +25 08 17.0  GSC-2.3, 1990.568
                    20 20 54.36 +25 08 16.0  Pan-STARRS
                    20 20 54.36 +25 08 15.9  GAIA1

The Pan-STARRS Sloan 'psf' magnitudes for this star are:

g = 20.41
r = 20.42
i = 20.52
z = 20.57

...implying a blue object, especially considering the
fairly low galactic latitude.


\Brian