PNV J20205397+2508145: new transient (12.3 mag) in Vulpecula

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Tue, 09/12/2017 - 18:27

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

2017 09 12.542 UT
Discovered by T. Kojima, Gunma-ken, Japan, who found this on three frames taken by Canon EOS 6D + 135-mm f3.2 lens and confirmed this (mag.= 12.7) taken on 2017 Sept. 12.67 UT using 200-mm f/3.2 lens. Nothing is visible at this location on a frame taken on 2017 Sept. 2.719 UT. An image at
http://www.oaa.gr.jp/~oaacs/image/PNinVul2017.jpg

Follow up-reports:
http://www.cbat.eps.harvard.edu/unconf/followups/J20205397+2508145.html

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.

Clear skies,
Patrick

Affiliation
American Association of Variable Star Observers (AAVSO)
I'm collecting BVRI data on

I'm collecting BVRI data on this target now.  Are there good comp stars available for this field?  Will try to upload into VPhot in the morning.

The position is clearly off ;  I have this object at 20:20:54.36 and +25:08:15.9 in images binned 2x2 (1.26"/px) -- will get some unbinned to see if the position can be refined a bit more.

Clear skies,

 

Brad Vietje, VBPA

Newbury, VT

www.nkaf.org

Affiliation
American Association of Variable Star Observers (AAVSO)
Upcountry

Hello Brad

Not observing this object, but am upcountry and observed last 2 nights.  I would like to see your observatory.  Are you there any days this week or next?  Can you refresh my memory on the address?

Gary

Affiliation
American Association of Variable Star Observers (AAVSO)
Position derived from a

Position derived from a single, unbinned V-band image plate solved with UCAC4 agrees exactly with my earlier position:  20:20:54.36 and +25:08:15.9.

No comp stars indicated in a 43' chart to mag 16 in VSP;  waiting for the VPhot queue to die down before I can get a peek at a single uploaded image.  Wondering what comps people are using to estimate the magnitude of this target?  I can report instrument mag'sfrom maxIm DL 6, but these could be a little off the mark.

Clear skies,

Brad Vietje, VBPA

Newbury, VT

www.nkaf.org

Dwarf nova?

Hello,

I took a low-resolution spectrum (R=865) last night and I think this object is rather a dwarf nova than a classical nova: it remembers me more to SS Cyg near the maximum than a classical nova due to the absence of strong emission bands and P-Cyg profiles...

Greetings

Fran