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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - M31N 2008-12a - the remarkable recurrent nova in M31
T2 - Pan-Chromatic observations of the 2015 eruption
AU - Darnley, M. J.
AU - Henze, M.
AU - Bode, M. F.
AU - Hachisu, I.
AU - Hernanz, M.
AU - Hornoch, K.
AU - Hounsell, R.
AU - Kato, M.
AU - Ness, J. -U.
AU - Osborne, J. P.
AU - Page, K. L.
AU - Ribeiro, V. A. R. M.
AU - Rodriguez-Gil, P.
AU - Shafter, A. W.
AU - Shara, M. M.
AU - Steele, I. A.
AU - Williams, S. C.
AU - Arai, A.
AU - Arcavi, I.
AU - Barsukova, E. A.
AU - Boumis, P.
AU - Chen, T.
AU - Fabrika, S.
AU - Figueira, J.
AU - Gehrels, N.
AU - Godon, P.
AU - Goranskij, V. P.
AU - Harman, D. J.
AU - Hartmann, D. H.
AU - Hosseinzadeh, G.
AU - Horst, J. Chuck
AU - Itagaki, K.
AU - Jose, J.
AU - Kabashima, F.
AU - Kaur, A.
AU - Kawai, N.
AU - Kennea, J. A.
AU - Kiyota, S.
AU - Kucakova, H.
AU - Lau, K. M.
AU - Maehara, H.
AU - Naito, H.
AU - Nakajima, K.
AU - Nishiyama, K.
AU - O'Brien, T. J.
AU - Quimby, R.
AU - Sala, G.
AU - Sano, Y.
AU - Sion, E. M.
AU - Valeev, A. F.
AU - Watanabe, F.
AU - Watanabe, M.
AU - Williams, B. F.
AU - Xu, Z.
PY - 2016/12/20
Y1 - 2016/12/20
N2 - The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption ten times, including yearly eruptions from 2008-2014. With a measured recurrence period of $P_\mathrm{rec}=351\pm13$ days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground and space-based follow-up programs. In this paper we present the 2015 detection; visible to near-infrared photometry and visible spectroscopy; and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2m (Hawaii) discovered the 2015 eruption, estimated to have commenced at Aug. $28.28\pm0.12$ UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities $\sim13000$ km s$^{-1}$, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early super-soft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is $P_\mathrm{rec}=174\pm10$ d, and we expect the next eruption of M31N 2008-12a to occur around mid-Sep. 2016.
AB - The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption ten times, including yearly eruptions from 2008-2014. With a measured recurrence period of $P_\mathrm{rec}=351\pm13$ days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground and space-based follow-up programs. In this paper we present the 2015 detection; visible to near-infrared photometry and visible spectroscopy; and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2m (Hawaii) discovered the 2015 eruption, estimated to have commenced at Aug. $28.28\pm0.12$ UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities $\sim13000$ km s$^{-1}$, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early super-soft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is $P_\mathrm{rec}=174\pm10$ d, and we expect the next eruption of M31N 2008-12a to occur around mid-Sep. 2016.
KW - astro-ph.SR
KW - astro-ph.HE
KW - galaxies: individual (M31)
KW - novae, cataclysmic variables
KW - stars: individual (M31N 2008-12a)
KW - ultraviolet: stars
KW - X-rays: binaries
U2 - 10.3847/1538-4357/833/2/149
DO - 10.3847/1538-4357/833/2/149
M3 - Journal article
VL - 833
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 149
ER -