[vsnet-chat 1067] (fwd) PG 2337+300: the Unknown PG CV (Ringwald)

[Taichi Kato <tkato>]

Date: Tue, 21 Jul 1998 20:22:30 -0400 (EDT)
From: Fred Ringwald <ringwald@astro.psu.edu>
Subject: PG 2337+300: the Unknown PG CV


Dear vsnet observers,

Would anyone who is interested please monitor PG 2337+300?  It was
recently found by Koen & Orosz (1998 IBVS 4539: see
http://ogyalla.konkoly.hu/IBVS/4501.html) to be a PG CV, or cataclysmic
variable from the Palomar-Green survey (Green, Schmidt, \& Liebert 1986,
ApJS, 61, 305), at about 14th magnitude. 

PG 2337+300 is now well placed for observation.  What is needed most is
what amateur observers do best: to be observed once per night for a few
weeks or longer, to search for dwarf nova outbursts or other variability. 
PG 2337+300 is known to flicker on timescales of tens of seconds, which is
how Koen & Orosz found it to be a CV, and not a hot subdwarf, as
previously thought.  Its orbital period is unknown, so a time-resolved
search for eclipses, an orbital hump, or superhumps would also be of
interest. 

Here are original coordinates from the PG catalog, which should be
accurate to within 5-10": 
                         RA(1950)    Dec(1950)      B
PG 2337+300             23 37 33.2   +30 01 10    14.40

Similar errors should apply to coordinates I have precessed to J2000: 

                         RA(2000)    Dec(2000)      B
PG 2337+300             23 40 03.3   +30 17 48    14.40    

Green, Schmidt, & Liebert (1986) give a finding chart.  Downes & Shara
(1993, PASP) and Downes, Webbink, & Shara (1997, PASP) do not give finding
charts, because PG 2337+300 was only so recently recognized as a CV. 

Dr. Chris Koen (1998, private communication) has obtained high-speed
photometry of between 200 and 300 objects classified by the PG catalog as
subdwarfs.  PG 2337+300 was only one that flickers.  The PG catalog listed
161 stars classified as "sd", as was PG 2337+300, and 977 subdwarfs of all
types.  At this rate, there shouldn't be more than 3 or 4 "missing" PG
CVs, although finding them will require a great deal of telescope time
(just ask Chris). 

Making nightly observations of PG 2337+300 over time to check for
outbursts would be a whole lot easier.  If you are interested, please feel
free to download the finding chart I made in gif format with SkyView
(http://skyview.gsfc.nasa.gov/skyview.html).  This chart is available on
my Web page, at the address below.  It is 8.5 arcminutes on a side, with
North at the top, East to the left, and PG 2337+300 marked, in the center. 
Clear skies, good observing, and best regards,

=======================================================================
Fred Ringwald                    ... to further the progress of science,
Dept. of Astronomy & Astrophysics    to guide to an understanding
The Pennsylvania State University         of the majesty of the heavens,
525 Davey Laboratory                 to emphasize that
University Park, PA 16802-6305      under the great celestial firmament,
U. S. A.                     there is order, interdependence, and unity.
Phone: +1-814-863-1756                    -- Adler Planetarium, Chicago
  Fax: +1-814-863-3399
E-mail: ringwald@astro.psu.edu  http://vsnet.astro.psu.edu/users/ringwald/

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