The evolution of luminous red nova AT 2017jfs in NGC 4470
Journal
Date Issued
2019
Author(s)
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Chen, T. -W.
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Cai, Y. -Z.
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Morales-Garoffolo, A.
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Cano, Z.
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•
Barsukova, E. A.
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•
Berton, M.
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Bose, S.
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•
Callis, E.
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Cannizzaro, G.
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Cartier, R.
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Chen, Ping
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Dong, Subo
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Dyrbye, S.
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•
Flörs, A.
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Fraser, M.
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Geier, S.
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Goranskij, V. P.
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Kann, D. A.
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Kuncarayakti, H.
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Reguitti, A.
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Reynolds, T.
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Losada, I. R.
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Sagués Carracedo, A.
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Schweyer, T.
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Smartt, S. J.
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Tatarnikov, A. M.
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Valeev, A. F.
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Vogl, C.
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Wevers, T.
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de Ugarte Postigo, A.
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Izzo, L.
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Inserra, C.
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Kankare, E.
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Maguire, K.
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Smith, K. W.
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Stalder, B.
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•
Thöne, C. C.
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Valerin, G.
•
Young, D. R.
Abstract
We present the results of our photometric and spectroscopic follow-up of the intermediate-luminosity optical transient AT 2017jfs. At peak, the object reaches an absolute magnitude of Mg = -15.46 ± 0.15 mag and a bolometric luminosity of 5.5 × 1041 erg s-1. Its light curve has the double-peak shape typical of luminous red novae (LRNe), with a narrow first peak bright in the blue bands, while the second peak is longer-lasting and more luminous in the red and near-infrared (NIR) bands. During the first peak, the spectrum shows a blue continuum with narrow emission lines of H and Fe II. During the second peak, the spectrum becomes cooler, resembling that of a K-type star, and the emission lines are replaced by a forest of narrow lines in absorption. About 5 months later, while the optical light curves are characterized by a fast linear decline, the NIR ones show a moderate rebrightening, observed until the transient disappears in solar conjunction. At these late epochs, the spectrum becomes reminiscent of that of M-type stars, with prominent molecular absorption bands. The late-time properties suggest the formation of some dust in the expanding common envelope or an IR echo from foreground pre-existing dust. We propose that the object is a common-envelope transient, possibly the outcome of a merging event in a massive binary, similar to NGC 4490-2011OT1.
Table A.1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/625/L8
Volume
625
Start page
L8
Issn Identifier
0004-6361
Ads BibCode
2019A&A...625L...8P
Rights
open.access
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