On the triple peaks of SNHunt248 in NGC 5806
Number of Authors: 22
2015 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 581, L4Article in journal (Refereed) Published
We present our findings on a supernova (SN) impostor, SNHunt248, based on optical and near-IR data spanning similar to 15 yr before discovery, to similar to 1 yr post-discovery. The light curve displays three distinct peaks, the brightest of which is at MR similar to -15.0 mag. The post-discovery evolution is consistent with the ejecta from the outburst interacting with two distinct regions of circumstellar material. The 0.5-2.2 mu m spectral energy distribution at -740 d is well-matched by a single 6700 K blackbody with log(L/L-circle dot) similar to 6.1. This temperature and luminosity support previous suggestions of a yellow hypergiant progenitor; however, we find it to be brighter than the brightest and most massive Galactic late-F to early-G spectral type hypergiants. Overall the historical light curve displays variability of up to similar to +/- 1 mag. At current epochs (similar to 1 yr post-outburst), the absolute magnitude (MR similar to -9 mag) is just below the faintest observed historical absolute magnitude similar to 10 yr before discovery.
Place, publisher, year, edition, pages
2015. Vol. 581, L4
stars: massive, stars: mass-loss, supernovae: general, supernovae: individual: SNHunt248
IdentifiersURN: urn:nbn:se:su:diva-122767DOI: 10.1051/0004-6361/201526631ISI: 000361803900150OAI: oai:DiVA.org:su-122767DiVA: diva2:868782