A1 Refereed original research article in a scientific journal

SN 2011A: A LOW-LUMINOSITY INTERACTING TRANSIENT WITH A DOUBLE PLATEAU AND STRONG SODIUM ABSORPTION




Authorsde Jaeger T, Anderson JP, Pignata G, Hamuy M, Kankare E, Stritzinger MD, Benetti S, Bufano F, Elias-Rosa N, Folatelli G, Forster F, Gonzaez-Gaitan S, Gutierrez CP, I1900nserra C, Kotak R, Lira P, Morrell N, Taddia F, Tomasella L, Tomasella L

PublisherIOP PUBLISHING LTD

Publication year2015

JournalAstrophysical Journal

Journal name in sourceASTROPHYSICAL JOURNAL

Journal acronymASTROPHYS J

Article numberARTN 63

Volume807

Issue1

Number of pages16

ISSN0004-637X

DOIhttps://doi.org/10.1088/0004-637X/807/1/63


Abstract
We present optical photometry and spectroscopy of the optical transient SN 2011A. Our data span 140 days after discovery including BVRI u'g'r'i'z' photometry and 11 epochs of optical spectroscopy. Originally classified as a type IIn supernova (SN IIn) due to the presence of narrow Ha emission, this object shows exceptional characteristics. First, the light curve shows a double plateau, a property only observed before in the impostor SN 1997bs. Second, SN 2011A has a very low luminosity (M-V = -15.72), placing it between normal luminous SNe IIn and SN impostors. Third, SN 2011A shows low velocity and high equivalent width absorption close to the sodium doublet, which increases with time and is most likely of circumstellar origin. This evolution is also accompanied by a change in line profile; when the absorption becomes stronger, a P Cygni profile appears. We discuss SN 2011A in the context of interacting SNe IIn and SN impostors, which appears to confirm the uniqueness of this transient. While we favor an impostor origin for SN 2011A, we highlight the difficulty in differentiating between terminal and non-terminal interacting transients.



Last updated on 2024-26-11 at 14:13