Keck/DEIMOS spectroscopy of SN 2009ip: A Broad P-Cyg He I line re-emerging?
ATel #4491; Saurabh W. Jha, Curtis McCully, Brandon Patel (Rutgers University)
on 16 Oct 2012; 22:35 UT
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Credential Certification: Saurabh Jha (email@example.com)
Subjects: Optical, Supernovae
Referred to by ATel #: 4532
We obtained Keck II(+ DEIMOS) spectroscopy of the type IIn SN 2009ip
(Smith & Mauerhan, ATel #4412) covering 465-975 nm with the 600 l/mm
grating (R ~ 2000) on 2012 October 15.3 UT. The spectrum shows a blue
continuum with Balmer, Paschen, and He I emission lines. We see clear
intermediate and narrow width components for H-beta, H-alpha, and He I
5876, with the last showing an asymmetric profile.
We also report the possible re-emergence of a broad P-Cyg trough for
He I 5876, with an expansion velocity of 13,100 km/s at the line
minimum. Unlike the broad P-Cyg profiles of SN 2009ip from
August-September (Mauerhan et al. 2012, arXiv:1209.6320; Vinko et al.,
ATel #4435), we do not see as strong absorption in the Balmer lines.
Comparing our spectrum to other recent observations (Gall et al., ATel
#4454; Bohlsen, ATel #4477; Vinko et al., ATel #4480), it seems clear
that SN 2009ip is rapidly evolving. Continuing observations are
A figure showing our optical spectrum is available at: http://www.physics.rutgers.edu/~saurabh/sn2009ip.png