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Special Notice 255: Cataclysmic Variable in Draco = PNV J18422792+4837425

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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. 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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