We present Hubble Space Telescope (HST) imaging of the site of SN 2015bh in the nearby spiral galaxy NGC 2770 taken between 2017 and 2019, nearly four years after the peak of the explosion. In 2017–2018, the transient fades steadily in optical filters before declining more slowly to
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Unveiling the Nature of SN 2011fh: A Young and Massive Star Gives Rise to a Luminous SN 2009ip−like Event
Abstract In recent years, many Type IIn supernovae have been found to share striking similarities with the peculiar SN 2009ip, whose true nature is still under debate. Here, we present 10 yr of observations of SN 2011fh, an interacting transient with spectroscopic and photometric similarities to SN 2009ip. SN 2011fh had an M r ∼ −16 mag brightening event, followed by a brighter M r ∼ −18 mag luminous outburst in 2011 August. The spectra of SN 2011fh are dominated by narrow to intermediate Balmer emission lines throughout its evolution, with P Cygni profiles indicating fast-moving material at ∼6400 km s −1 . HST/WFC3 observations from 2016 October revealed a bright source with M F814W ≈ −13.3 mag, indicating that we are seeing the ongoing interaction of the ejecta with the circumstellar material or that the star might be going through an eruptive phase five years after the luminous outburst of 2011. Using HST photometry of the stellar cluster around SN 2011fh, we estimated an age of ∼4.5 Myr for the progenitor, which implies a stellar mass of ∼60 M ⊙ , using single-star evolution models, or a mass range of 35–80 M ⊙ , considering a binary system. We more »
- Award ID(s):
- 1814440
- Publication Date:
- NSF-PAR ID:
- 10348491
- Journal Name:
- The Astrophysical Journal
- Volume:
- 928
- Issue:
- 2
- Page Range or eLocation-ID:
- 138
- ISSN:
- 0004-637X
- Sponsoring Org:
- National Science Foundation
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