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arXiv · 2004.01488

SiO maser astrometry of the red transient V838 Monocerotis

Gisela N. Ortiz-Leon·Karl M. Menten·Tomasz Kaminski·Andreas Brunthaler·Mark J. Reid·Romuald Tylenda
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Abstract

We present multi-epoch observations with the VLBA of SiO maser emission in the v=1, J=1-0 transition at 43 GHz from the remnant of the red nova V838 Mon. We model the positions of maser spots to derive a parallax of 0.166+/-0.060 mas. Combining this parallax with other distance information results in a distance of 5.6+/-0.5 kpc, which agrees with an independent geometric distance of 6.1+/-0.6 kpc from modeling polarimetry images of V838 Mon's light echo. Combining these results, and including a weakly constraining Gaia DR2 parallax, yields a best estimate of distance of 5.9+/-0.4 kpc. The maser spots are located close to the peaks of continuum at ~225 GHz and SiO J=5-4 thermal emission detected with ALMA. The proper motion of V838 Mon confirms its membership in a small open cluster in the Outer spiral arm of the Milky Way.

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Gisela N. Ortiz-Leon, Karl M. Menten, Tomasz Kaminski, Andreas Brunthaler, Mark J. Reid, Romuald Tylenda. 2020-04-03. SiO maser astrometry of the red transient V838 Monocerotis. https://doi.org/10.1051/0004-6361/202037712

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