AAVSO Special Notice #255 - Cataclysmic Variable in Draco

AAVSO Special Notice #255

Cataclysmic Variable in Draco = PNV J18422792+4837425
September 14, 2011

IAU CBAT Central Bureau Electronic Telegram 2818 (Daniel W. E.
Green, ed.) announces the discovery by Hideo Nishimura, Miyawaki,
Kakegawa, Shizuoka-ken, Japan, of a cataclysmic variable in Draco
on 2011 Sept. 5.529 UT at magnitude 11.8 (reported by S. Nakano,
Sumoto, Japan). The variable was designated PNV J18422792+4837425
when posted on the Central Bureau's TOCP webpage.

A spectrum obtained by Ulisse Munari, Istituto Nazionale di
Astrofisica, Padova Astronomical Observatory, on 2011 September
6.841 UT with the Asiago Astrophysical Observatory 1.22-m telescope
is typical of a cataclysmic variable near maximum.

Munari also reports that nothing was visible at the location of
the object on the Palomar Sky Survey. This suggests the possibility
that it may be a WZ Sge-type variable, based on its large amplitude.
CCD time series are requested to determine the nature of this
object and to search for superhumps. Visual observations are also
welcome.

Over 800 observations of PNV J18422792+4837425 have been submitted
to the AAVSO International Database to date, by Richard Sabo,
Bozeman, MT, and Joseph Ulowetz, Northbrook, IL; the most recent
one is from 2011 September 13.2285 UT at magnitude 12.621 CV by
Ulowetz.

Coordinates: RA 18 42 27.92 Dec. +48 37 42.5 (2000.0)

Charts for PNV J18422792+4837425 (000-BKD-643) may be plotted
using VSP (http://www.aavso.org/vsp). To accomodate the location of
the comparison star sequence relative to the variable, it is
recommended that observers choose a D-scale chart and a limiting
magnitude of 16.0.

Until an official name is assigned by the GCVS team, please report
observations of this object to the AAVSO International Database
as PNV J18422792+4837425.

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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