Darnley, MJ;
Hounsell, R;
Godon, P;
Perley, DA;
Henze, M;
Kuin, NPM;
Williams, BF;
... Shara, MM; + view all
(2017)
Inflows, Outflows, and a Giant Donor in the Remarkable Recurrent Nova M31N 2008-12a?—Hubble Space Telescope Photometry of the 2015 Eruption.
Astrophysical Journal
, 849
(2)
, Article 96. 10.3847/1538-4357/aa9062.
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Abstract
The recurrent nova M31N 2008-12a experiences annual eruptions, contains a near-Chandrasekhar-mass white dwarf, and has the largest mass accretion rate in any nova system. In this paper, we present Hubble Space Telescope (HST) WFC3/UVIS photometry of the late decline of the 2015 eruption. We couple these new data with archival HST observations of the quiescent system and Keck spectroscopy of the 2014 eruption. The late-time photometry reveals a rapid decline to a minimum luminosity state, before a possible recovery/rebrightening in the run up to the next eruption. Comparison with accretion disk models supports the survival of the accretion disk during the eruptions, and uncovers a quiescent disk mass accretion rate of the order of 10 -6 M ⊙ yr -1 , which may rise beyond 10 -5 M ⊙ yr -1 during the super-soft source phase - both of which could be problematic for a number of well-established nova eruption models. Such large accretion rates, close to the Eddington limit, might be expected to be accompanied by additional mass loss from the disk through a wind and even through collimated outflows. The archival HST observations, combined with the disk modeling, provide the first constraints on the mass donor: L donor = 103 -11 +12 L ⊙ , R donor = 14.14 -0.47 +0.46 R ⊙ , and T eff,donor = 4890 ± 110 K, which may be consistent with an irradiated M31 red-clump star. Such a donor would require a system orbital period ≳ days. Our updated analysis predicts that the M31N 2008-12a WD could reach the Chandrasekhar mass in < 20 kyr.
| Type: | Article |
|---|---|
| Title: | Inflows, Outflows, and a Giant Donor in the Remarkable Recurrent Nova M31N 2008-12a?—Hubble Space Telescope Photometry of the 2015 Eruption |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/aa9062 |
| Publisher version: | https://doi.org/10.3847/1538-4357/aa9062 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | accretion, accretion disks; novae, cataclysmic variables; galaxies: individual (M31); stars: individual (M31N 2008-12a); ultraviolet: stars |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10025019 |
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