Spectroscopic classification of PSN J12211796+113025
ATel #4816; L. Tomasella, P. Ochner, S. Benetti, A. Pastorello, E. Cappellaro, L. Bedin, M. Turatto, S. Spiro, L. Tartaglia (Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica, INAF), A. Harutyunyan (Telescopio Nazionale Galileo, TNG), A. Dimai (Cortina d'Ampezzo, Italy, on behalf of Italian Supernovae Search Project - ISSP), M. T. Botticella (Osservatorio Astronomico di Capodimonte, INAF), G. Pignata, F. Bufano (Universidad Andres Bello), S. Valenti (University of California at Santa Barbara and Las Cumbres Observatory Global Telescope), N. Elias-Rosa (Institut de Ciencies de L'Espai - CSIC-IEEC, Barcelona)
on 15 Feb 2013; 21:04 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Stefano Benetti (stefano.benetti@oapd.inaf.it)
We report that optical spectra of PSN J12211796+113025 obtained on Feb. 14.93 UT
with the Asiago 1.82-m Copernico Telescope (+ AFOSC; range 340-820 nm; resolution 1.3 nm) and on Feb. 15.11 UT with the TNG (+Dolores; 320-800 nm,
resolution 1.4 nm) shows a blue continuum (Tbb ~ 15300 K) with superimposed narrow, unresolved (FWHM < 600 km/s) emission lines of H, [O II],
[O III], [N II] and [S II]. However, we cannot disentangle the intrinsic transient contribution to line emissions because of the heavy
contamination from nearby H II regions. From the observed wavelength of the Halpha and Hbeta peaks we derive a redshift z~0.0012 which coincides
with that given for the host NGC4294 (Brian et al., 2008, AJ 136,713 via NED). The spectra, together with the faint peak absolute magnitude of
the transient, about -14 assuming a distance modulus m-M=31.13, (from the Extragalactic Distance Database, Tully etal. 2009 AJ 138, 323),
suggest that PSN J12211796+1130252 is a supernova impostor, likely a major eruption of a luminous blue variable. Long term
photometric monitoring has been activated. The Asiago classification spectra are posted at this website: URL http://graspa.oapd.inaf.it.
