Special Notice #150: Request for observations of N LMC 09

AAVSO Special Notice #150

Request for observations of N LMC 09
April 3, 2009

Dr. Julian Osborne (Leicester) and collaborators have requested optical time-series photometry of the southern recurrent nova candidate N LMC 09 (W. Liller, IAUC 9019, D.W.E. Green, editor).  Time-series observations made with the Swift UVOT (M. Bode et al., ATel #2001) strongly suggest periodic behavior, but with an uncertain period.  The strongest signal detected is P = 1.19 +/- 0.01 days, but this may be an alias of the true period modulated by Swift's orbital period; it is possible but unlikely that the period is as low as 0.063 or 0.071 days. Bode et al. note that if the orbital period is 1.19 days, this system may belong to the U Sco or T Pyx subclasses of novae.  

The most recent observations in the AAVSO database (JD 2454918.98, 2009 March 28.48; T. Bohlsen, NSW, Australia) show N LMC 09 to be at V=15.90, (B-V)=-0.19.  This is relatively faint for intensive time-series, so please balance the shortest exposure times with the best signal to noise possible.  Bode et al report full-range amplitudes of 0.6 mag, so errors of 0.1 mag are sufficient to detect the variability with very high significance.  In the event it becomes clear that the true orbital period is 1.19 days, please increase exposure times to improve signal to noise.  Unfiltered observations are acceptable for this campaign; V-band observations are preferred if using a filter does not substantially impact signal to noise or integration times.

N LMC 09 is located at the following J2000 coordinates (H. Bond et al, IAUC 9019):

RA: 05 40 44.20 , Dec: -66 40 11.6

Charts for N LMC 09 may be created using VSP: http://www.aavso.org/observing/charts/vsp/index.html?pickname=N%20LMC%2009

Please promptly submit all data to the AAVSO using the name "N LMC 09" (AUID 000-BJJ-604).

This AAVSO Special Notice was prepared by M. Templeton.


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