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arXiv · 1907.01013

SN 2017gmr: An energetic Type II-P supernova with asymmetries

Jennifer E. Andrews·D. J. Sand·S. Valenti·Nathan Smith·Raya Dastidar·D. K. Sahu·Kuntal Misra·Avinash Singh·D. Hiramatsu·P. J. Brown·G. Hosseinzadeh·S. Wyatt·J. Vinko·G. C. Anupama·I. Arcavi·Chris Ashall·S. Benetti·Marco Berton·K. A. Bostroem·M. Bulla·J. Burke·S. Chen·L. Chomiuk·A. Cikota·E. Congiu·B. Cseh·Scott Davis·N. Elias-Rosa·T. Faran·Morgan Fraser·L. Galbany·C. Gall·A. Gal-Yam·Anjasha Gangopadhyay·M. Gromadzki·J. Haislip·D. A. Howell·E. Y. Hsiao·C. Inserra·E. Kankare·H. Kuncarayakti·V. Kouprianov·Brajesh Kumar·Xue Li·Han Lin·K. Maguire·P. Mazzali·C. McCully·P. Milne·Jun Mo·N. Morrell·M. Nicholl·P. Ochner·F. Olivares·A. Pastorello·F. Patat·M. Phillips·G. Pignata·S. Prentice·A. Reguitti·D. E. Reichart·Ó. Rodríguez·Liming Rui·Pankaj Sanwal·K. Sárneczky·M. Shahbandeh·Mridweeka Singh·S. Smartt·J. Strader·M. D. Stritzinger·R. Szakáts·L. Tartaglia·Huijuan Wang·Lingzhi Wang·Xiaofeng Wang·J. C. Wheeler·Danfeng Xang·O. Yaron·D. R. Young·Junbo Zhang
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Abstract

We present high-cadence ultraviolet (UV), optical, and near-infrared (NIR) data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical lightcurve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early lightcurve indicates a ~500R$_{\odot}$ progenitor radius, consistent with a rather compact red supergiant, and late-time luminosities indicate up to 0.130 $\pm$ 0.026 M$_{\odot}$ of $^{56}$Ni are present, if the lightcurve is solely powered by radioactive decay, although the $^{56}$Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multi-peaked emission lines of H$\alpha$ and [O I] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first two days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta.

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Jennifer E. Andrews, D. J. Sand, S. Valenti, Nathan Smith, Raya Dastidar, D. K. Sahu, Kuntal Misra, Avinash Singh, D. Hiramatsu, P. J. Brown, G. Hosseinzadeh, S. Wyatt, J. Vinko, G. C. Anupama, I. Arcavi, Chris Ashall, S. Benetti, Marco Berton, K. A. Bostroem, M. Bulla, J. Burke, S. Chen, L. Chomiuk, A. Cikota, E. Congiu, B. Cseh, Scott Davis, N. Elias-Rosa, T. Faran, Morgan Fraser, L. Galbany, C. Gall, A. Gal-Yam, Anjasha Gangopadhyay, M. Gromadzki, J. Haislip, D. A. Howell, E. Y. Hsiao, C. Inserra, E. Kankare, H. Kuncarayakti, V. Kouprianov, Brajesh Kumar, Xue Li, Han Lin, K. Maguire, P. Mazzali, C. McCully, P. Milne, Jun Mo, N. Morrell, M. Nicholl, P. Ochner, F. Olivares, A. Pastorello, F. Patat, M. Phillips, G. Pignata, S. Prentice, A. Reguitti, D. E. Reichart, Ó. Rodríguez, Liming Rui, Pankaj Sanwal, K. Sárneczky, M. Shahbandeh, Mridweeka Singh, S. Smartt, J. Strader, M. D. Stritzinger, R. Szakáts, L. Tartaglia, Huijuan Wang, Lingzhi Wang, Xiaofeng Wang, J. C. Wheeler, Danfeng Xang, O. Yaron, D. R. Young, Junbo Zhang. 2019-07-01. SN 2017gmr: An energetic Type II-P supernova with asymmetries. https://doi.org/10.3847/1538-4357/ab43e3

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