SN 2015ba: a Type IIP supernova with a long plateau

Journal
Date Issued
2018
Author(s)
Dastidar, Raya
•
Misra, Kuntal
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Hosseinzadeh, G.
•
•
Pumo, M. L.
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Valenti, S.
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McCully, C.
•
•
Arcavi, I.
•
•
Singh, Mridweeka
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Gangopadhyay, Anjasha
•
Howell, D. A.
•
Morales-Garoffolo, Antonia
•
•
Kumar, Brijesh
•
•
•
•
Ochner, P.
•
Sahu, D. K.
•
Anupama, G. C.
•
Pandey, S. B.
DOI
Abstract
We present optical photometry and spectroscopy from about a week after explosion to ∼272 d of an atypical Type IIP supernova, SN 2015ba, which exploded in the edge-on galaxy IC 1029. SN 2015ba is a luminous event with an absolute V-band magnitude of -17.1 ± 0.2 mag at 50 d since explosion and has a long plateau lasting for ∼123 d. The distance to the SN is estimated to be 34.8 ± 0.7 Mpc using the expanding photosphere and standard candle methods. High-velocity H Balmer components constant with time are observed in the late-plateau phase spectra of SN 2015ba, which suggests a possible role of circumstellar interaction at these phases. Both hydrodynamical and analytical modelling suggest a massive progenitor of SN 2015ba with a pre-explosion mass of 24-26 M☉. However, the nebular spectra of SN 2015ba exhibit insignificant levels of oxygen, which is otherwise expected from a massive progenitor. This might be suggestive of the non-monotonical link between O-core masses and the zero-age main sequence mass of pre-supernova stars and/or uncertainties in the mixing scenario in the ejecta of supernovae.
Volume
479
Issue
2
Start page
2421
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2018MNRAS.479.2421D
Rights
open.access
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