Issue |
A&A
Volume 625, May 2019
|
|
---|---|---|
Article Number | L8 | |
Number of page(s) | 7 | |
Section | Letters to the Editor | |
DOI | https://doi.org/10.1051/0004-6361/201935511 | |
Published online | 17 May 2019 |
Letter to the Editor
The evolution of luminous red nova AT 2017jfs in NGC 4470⋆
1
INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
e-mail: andrea.pastorello@inaf.it
2
Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstraße 1, 85748 Garching bei München, Germany
3
Dipartimento di Fisica e Astronomia, Università di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
4
Department of Applied Physics, University of Cádiz, Campus of Puerto Real, 11510 Cádiz, Spain
5
Instituto de Astrofísica de Andalucía (IAA-CSIC), Glorieta de la Astronomía s/n, 18008 Granada, Spain
6
INAF – Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, 34143 Trieste, Italy
7
Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Karachai-Cherkesia 369167, Russia
8
Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Quantum, Vesilinnantie 5, 20014 Turku, Finland
9
Aalto University Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
10
Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Road 5, Hai Dian District, Beijing 100871, PR China
11
INAF – Osservatorio Astrofisico di Catania, Via Santa Sofia 78, 95123 Catania, Italy
12
School of Physics, O’Brien Centre for Science North, University College Dublin, Belfield Dublin 4, Ireland
13
SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
14
Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
15
Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile
16
Nordic Optical Telescope, Apartado 474, 38700 Santa Cruz de La Palma, Santa Cruz de Tenerife, Spain
17
Institute of Space Sciences (ICE, CSIC), Campus UAB, Camí de Can Magrans s/n, 08193 Cerdanyola del Vallès (Barcelona), Spain
18
Institut d’Estudis Espacials de Catalunya (IEEC), c/Gran Capità 2-4, Edif. Nexus 201, 08034 Barcelona, Spain
19
European Southern Observatory, Karl-Schwarzschild-Straße 2, 85748 Garching bei München, Germany
20
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching bei München, Germany
21
Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching bei München, Germany
22
Gran Telescopio Canarias (GRANTECAN), Cuesta de San José s/n, 38712 Breña Baja, La Palma, Spain
23
Instituto de Astrofísica de Canarias, Vía Láctea s/n, 38200 La Laguna, Tenerife, Spain
24
Sternberg Astronomical Institute, Lomonosov Moscow University, Universitetsky Ave. 13, 119992 Moscow, Russia
25
Tuorla Observatory, Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
26
Istituto di Astrofisica e Planetologia Spaziali (INAF), Via del Fosso del Cavaliere 100, 00133 Roma, Italy
27
Departamento de Ciencias Físicas, Universidad Andrés Bello, Santiago, Chile
28
Nordita, KTH Royal Institute of Technology and Stockholm University, 10691 Stockholm, Sweden
29
Department of Astronomy, AlbaNova University Center, Stockholm University, 10691 Stockholm, Sweden
30
The Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, 10691 Stockholm, Sweden
31
Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN, UK
32
Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
33
Institute of Astronomy, University of Cambridge, Madingley Road Cambridge CB3 0HA, UK
34
Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
35
School of Physics & Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA, UK
36
School of Physics, Trinity College Dublin, Dublin 2, Ireland
37
LSST, 950 North Cherry Avenue, Tucson AZ 85719, USA
38
The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm, Sweden
Received:
21
March
2019
Accepted:
23
April
2019
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.
Key words: binaries: close / stars: massive / supernovae: individual: AT 2017jfs / supernovae: individual: NGC 440−2011OT1 / stars: winds, outflows
Table A.1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/625/L8
© ESO 2019
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