Pan-chromatic observations of the recurrent nova LMC 2009a (LMC 1971b)

Journal Article · Sat Feb 20 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/818/2/145· OSTI ID:22887011

Bode, M. F.; Darnley, M. J. ^[1]; Beardmore, A. P.; Osborne, J. P.; Page, K. L. ^[2]; Walter, F. M. ^[3]; Krautter, J. ^[4]; Melandri, A. ^[5]; Ness, J. -U. ^[6]; O’Brien, T. J. ^[7]; Orio, M. ^[8]; Schwarz, G. J. ^[9]; Shara, M. M. ^[10]; Starrfield, S. ^[11]

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1. Astrophysics Research Institute, Liverpool John Moores University, IC2, Brownlow Hill, Liverpool, L3 5RF (United Kingdom)
2. Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH (United Kingdom)
3. Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States)
4. Landessternwarte-Zentrum für Astronomie der Universität, Königstuhl, D-69117 Heidelberg (Germany)
5. INAF-Osservatorio Astronomico Brera, via E. Bianchi 46, I-23807, Merate, LC (Italy)
6. XMM-Newton Science Operations Center, European Space Astronomy Center, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain)
7. Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)
8. Department of Astronomy, University of Wisconsin, 475 N. Charter Str., Madison, WI 53704 (United States)
9. American Astronomical Society, 2000 Florida Ave., NW, Suite 300, DC 20009-1231 (United States)
10. American Museum of Natural History, 79th Street and Central Park West, New York, NY 10024 (United States)
11. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

Nova LMC 2009a is confirmed as a recurrent nova (RN) from positional coincidence with nova LMC 1971b. The observational data set is one of the most comprehensive for any Galactic or extragalactic RN: optical and near-IR photometry from outburst until over 6 years later; optical spectra for the first 6 months, and Swift satellite ultraviolet (UV) and X-ray observations from 9 days to almost 1 year post-outburst. We find M{sub V} = −8.4 ± 0.8{sub r} ± 0.7{sub s} and expansion velocities between 1000 and 4000 km s{sup −1}. Coronal line emission before day 9 indicates shocks in the ejecta. Strengthening of He iiλ4686 preceded the emergence of the super-soft source (SSS) in X-rays at ∼63–70 days, which was initially very variable. Periodic modulations, P = 1.2 days, most probably orbital in nature, were evident in the UV and optical from day 43. Subsequently, the SSS shows an oscillation with the same period but with a delay of 0.28P. The progenitor system has been identified; the secondary is most likely a sub-giant feeding a luminous accretion disk. Properties of the SSS infer a white dwarf (WD) mass 1.1 M{sub ⊙} ≲ M{sub WD} ≲ 1.3 M{sub ⊙}. If the accretion occurs at a constant rate, M-dot {sub acc}≃3.6{sub −2.5}{sup +4.7}×10{sup −7} M{sub ⊙} yr{sup −1} is needed, consistent with nova models for an inter-eruption interval of 38 years, low outburst amplitude, progenitor position in the color–magnitude diagram, and spectral energy distribution at quiescence. We note striking similarities between LMC 2009a and the Galactic nova KT Eri, suggesting that KT Eri is a candidate RN.

• OSTI ID: 22887011
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 818; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ACCRETION DISKS
EMISSION
ENERGY SPECTRA
ERUPTION
GALAXIES
MASS
NOVA MODEL
NOVAE
OSCILLATIONS
PERIODICITY
PHOTOMETRY
SATELLITES
ULTRAVIOLET RADIATION
VELOCITY
WHITE DWARF STARS