TY - JOUR
T1 - V838 monocerotis
T2 - the central star and its environment a decade after outburst
AU - Chesneau, O.
AU - Millour, F.
AU - De Marco, O.
AU - Bright, S. N.
AU - Spang, A.
AU - Banerjee, D. P K
AU - Ashok, N. M.
AU - Kamiński, T.
AU - Wisniewski, J. P.
AU - Meilland, A.
AU - Lagadec, E.
N1 - Copyright ESO 2014. First published in Astronomy and astrophysics 569, L3, 2014, published by EDP Sciences. The original publication is available at http://doi.org/10.1051/0004-6361/201424458
PY - 2014/9
Y1 - 2014/9
N2 - Aims. V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. Methods. We obtained near-and mid-IR interferometric observations of V838 Mon with the AMBER and MIDI recombiners located at the Very Large Telescope Interferometer (VLTI) array. The MIDI two-beam observations were obtained with the 8?m unit telescopes between October 2011 and February 2012. The AMBER three-beam observations were obtained with the compact array (B = 35 m) in April 2013 and the long array (B = 140m) in May 2014, using the 1.8 m auxiliary telescopes.Results. A significant new result is the detection of a compact structure around, as seen from MIDI data. The extension of the structure increases from a FWHM of 25 mas at 8 μ m to 70 mas at 13 μ m. At the adopted distance of D = 6.1 ± 0.6 kpc, the dust is distributed from about 150 to 400 AU around. The MIDI visibilities reveal a flattened structure whose aspect ratio increases with wavelength. The major axis is roughly oriented around a position angle of-10°, which aligns with previous polarimetric studies reported in the literature. This flattening can be interpreted as a relic of the 2002 eruption or as caused by the influence of the currently embedded B3V companion. The AMBER data provide a new diameter for the pseudo-photosphere, which shows that its diameter has decreased by about 40% in 10 yr, reaching a radius R∗ = 750 ± 200 R (3.5 ± 1.0 AU). Conclusions. After the 2002 eruption, which was interpreted as the merging of two stars, it seems that the resulting source is relaxing to a normal state. The nearby environment exhibits an equatorial overdensity of dust up to several hundred AU.
AB - Aims. V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. Methods. We obtained near-and mid-IR interferometric observations of V838 Mon with the AMBER and MIDI recombiners located at the Very Large Telescope Interferometer (VLTI) array. The MIDI two-beam observations were obtained with the 8?m unit telescopes between October 2011 and February 2012. The AMBER three-beam observations were obtained with the compact array (B = 35 m) in April 2013 and the long array (B = 140m) in May 2014, using the 1.8 m auxiliary telescopes.Results. A significant new result is the detection of a compact structure around, as seen from MIDI data. The extension of the structure increases from a FWHM of 25 mas at 8 μ m to 70 mas at 13 μ m. At the adopted distance of D = 6.1 ± 0.6 kpc, the dust is distributed from about 150 to 400 AU around. The MIDI visibilities reveal a flattened structure whose aspect ratio increases with wavelength. The major axis is roughly oriented around a position angle of-10°, which aligns with previous polarimetric studies reported in the literature. This flattening can be interpreted as a relic of the 2002 eruption or as caused by the influence of the currently embedded B3V companion. The AMBER data provide a new diameter for the pseudo-photosphere, which shows that its diameter has decreased by about 40% in 10 yr, reaching a radius R∗ = 750 ± 200 R (3.5 ± 1.0 AU). Conclusions. After the 2002 eruption, which was interpreted as the merging of two stars, it seems that the resulting source is relaxing to a normal state. The nearby environment exhibits an equatorial overdensity of dust up to several hundred AU.
UR - http://www.scopus.com/inward/record.url?scp=84908093604&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201424458
DO - 10.1051/0004-6361/201424458
M3 - Article
AN - SCOPUS:84908093604
SN - 0004-6361
VL - 569
SP - 1
EP - 5
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - L3
ER -