Swift and SMARTS observations of Nova SMC 2012
ATel #4501; G. J. Schwarz (AAS), J. P. Osborne, K. Page (U. Leicester), F. M. Walter (Stony Brook University), S. Starrfield (Arizona State U.)
on 19 Oct 2012; 16:28 UT
Credential Certification: Julian P Osborne (julo@star.le.ac.uk)
Subjects: Optical, Ultra-Violet, X-ray, Nova
Referred to by ATel #: 4853
We report on the Swift XRT and UVOT detection of the Nova SMC 2012
(OGLE-2012-NOVA-002) from a 3.85 ks observation on October 18, 2012. Six
photons were detected within a 10 pixel radius circle around the source
position for a X-ray count rate of (2.1^+0.7_-0.6)e-3 count/s (1σ) in
the 0.3 - 10 keV bandpass. With so few X-ray photons we are not able to
classify the X-ray spectrum at this time. The UVOT w2 band magnitude was
14.36 +/- 0.02 mag which is consistent with the U band photometry from ATel
#4487 obtained 4 days earlier.
On October 16 and 19, 2012, we obtained low resolution blue (5620 - 6930
Angstrom) and red (3650 - 5400 Angstrom) spectra from the SMARTS 1.5m
telescope. The red spectrum has a strong and asymmetric Hα
emission with an equivalent width of -1000 Angstroms and a FWHM of 2400
km/s. The next brightest line is He I (5876) and weaker He I (6678) is
also observed implying that the helium abundance is enhanced in the ejecta.
The [N II] (5755) line is also observed but not [Fe VII] (6087) or [O I]
(6300). There is a very weak feature around 6380 Angstroms that may be
associated with [Fe X] (6375). The strongest lines in the blue spectrum
are [Ne III] (3869) and [O III] (5007). Hβ has the same asymmetry
as seen in Hα.
Our optical spectra confirm that this source is a nova in its early nebular
phase. The lack of a clear soft X-ray detection along with the relatively
long t_2 decline time of ~ 40 days (ATel #4483) implies that the ejecta has
not yet sufficiently cleared to detect the underlying hot white dwarf but
will likely do so within the next few months. Since SMC novae come from a
low metallicity population, further observations at all wavelengths are
encouraged of this rare event.
We thank the Swift PI and operations team for the Swift observation.
