The pre-Nova light curve of CSS081007:030559+054715
ATel #1940; A. J. Drake (Caltech), E. C. Beshore (LPL), S. G. Djorgovski, A. A. Mahabal, M. J. Graham, R. Williams (Caltech); M. Catelan (PUC); S. M. Larson, R. Hill, A. Gibbs, A. Boattini (LPL/UA); E. Christensen (Gemini Observatory);
on 24 Feb 2009; 05:50 UT
Credential Certification: Andrew J. Drake (ajd@cacr.caltech.edu)
Subjects: Optical, Nova, Transient, Variables
The Nova CSS081007:030559+054715
was discovered by the Catalina Real-time Transient Survey (CRTS) on Oct 07 2008 UT and
followed
photometrically with the Palomar-60 between Oct 9 and Dec 12 2008. It was first classified as a possible
recurrent nova by Pejcha et al. (2008; ATEL#1825) and later as Oxygen/Neon nova by Prieto et al. (2008; ATel#1835). Beardmore et al. (2008; ATEL#1873) subsequently discovered significant X-ray emission and a 1.77 day period by monitoring it with SWIFT and Nelson et al. (2009; ATEL#1910) observed it with Chandra and found the object to exhibit a supersoft continuum superimposed with prominent emission lines. Goranskij and Metlova (2009; ATEL#1938) observed it optically in B,V and Rc between Dec. 3 2008 and Feb. 19 2009 and discovered two possible periods (1.694 and 0.6106 days).
We have analyzed 117 pre-outburst CSS observations of the object taken on 34 nights between Oct 1 2005 and Mar 10 2008 UT. We find the the object exhibited variability well in excess of one magnitude during this time. However, we find no evidence for the post-outburst 1.77 day X-ray period signal observed by Beardmore et al. (2008; ATEL#1873) or the 0.6106 and 1.694 day optical periods observed by Goranskij and Metlova (2009; ATEL#1938).
We find the best period for pre-outburst oscillations is 11.386 +/- 0.010 days. However, the data do not strongly constrain the periodic nature of the pre-outburst oscillations. On going CSS observations suggest that the Nova must not have begun the rapid decline noted by Goranskij and Metlova (2009; ATEL#1938) until after Jan 29th UT (rather the Jan. 22nd). Spectroscopic follow-up obtained with the SMARTs 1.5m telescope on Nov. 5th and is consistent with that of Prieto et al. (2008; ATel#1835).
Additional information can be found here: http://voeventnet.caltech.edu/feeds/ATEL/CRTS/NovaCSS081007.html
