Common envelope ejection for a luminous red nova in M101

Journal Article · Tue Jan 10 00:00:00 EST 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/834/2/107· OSTI ID:22869534

Blagorodnova, N.; Kasliwal, M. M.; Cao, Y.; Jencson, J.; Kulkarni, S. R.; Masci, F. J. ^[1]; Kotak, R.; Polshaw, J.; Kankare, E. ^[2]; Cody, A. M. ^[3]; Doran, G. B. ^[4]; Elias-Rosa, N. ^[5]; Fraser, M.; Gonzalez-Fernandez, C.; Mattila, S. ^[6]; Fremling, C. ^[7]; Harmanen, J. ^[8]; Kudritzki, R. -P.; Magnier, E. ^[9]; Manulis, I. ^[10] ; others, and

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1. Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States)
2. Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast BT7 1NN (United Kingdom)
3. Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
4. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)
5. INAF-Osservatorio Astronomico di Padova, Vicolo dell Osservatorio 5, I-35122 Padova (Italy)
6. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
7. Department of Astronomy, The Oskar Klein Center, Stockholm University, AlbaNova, SE-10691 Stockholm (Sweden)
8. Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, FI-21500 Piikkiö (Finland)
9. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
10. Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel)

We present the results of optical, near-infrared, and mid-infrared observations of M101 OT2015-1 (PSN J14021678+5426205), a luminous red transient in the Pinwheel galaxy (M101), spanning a total of 16 years. The light curve showed two distinct peaks with absolute magnitudes M{sub r}⩽−12.4 and M{sub r}≃−12, on 2014 November 11 and 2015 February 17, respectively. The spectral energy distributions during the second maximum show a cool outburst temperature of ≈3700 K and low expansion velocities (≈−300 km s{sup −1}) for the H i, Ca ii, Ba ii, and K i lines. From archival data spanning 15–8 years before the outburst, we find a single source consistent with the optically discovered transient, which we attribute to being the progenitor; it has properties consistent with being an F-type yellow supergiant with L ∼ 8.7 × 10{sup 4} L{sub ⊙}, T{sub eff}≈7000 K, and an estimated mass of M1=18±1 M{sub ⊙}. This star has likely just finished the H-burning phase in the core, started expanding, and is now crossing the Hertzsprung gap. Based on the combination of observed properties, we argue that the progenitor is a binary system, with the more evolved system overfilling the Roche lobe. Comparison with binary evolution models suggests that the outburst was an extremely rare phenomenon, likely associated with the ejection of the common envelope of a massive star. The initial mass of the primary fills the gap between the merger candidates V838 Mon (5−10 M{sub ⊙}) and NGC 4490-OT (30 M{sub ⊙}).

• OSTI ID: 22869534
• Journal Information: Astrophysical Journal, Vol. 834, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COMPARATIVE EVALUATIONS
ENERGY SPECTRA
EXPANSION
GALAXIES
MASS
NOVAE
RED GIANT STARS
ROCHE EQUIPOTENTIALS
STAR EVOLUTION
STELLAR WINDS
TRANSIENTS
VELOCITY