Astrometry of OH/IR Stars Using 1612MHz Hydroxyl Masers. I. Annual Parallaxes of WX Psc and OH138.0+7.2 MEConference on Why Galaxies Care About AGB Stars III: A Closer Look in Space and Time, JUL 28-AUG
Journal article, 2017
We report on the measurement of the trigonometric parallaxes of 1612 MHz hydroxyl masers around two asymptotic giant branch stars, WX. Psc and OH. 138.0+7.2, using the NRAO Very Long Baseline Array with in-beam phase referencing calibration. We obtain a 3s upper limit of. <= 5.3 mas on the parallax of WX. Psc, corresponding to a lower limit distance estimate of. 190 pc. The obtained parallax of OH. 138.0+7.2 is 0.52 +/- 0.09 mas (+/- 18%), corresponding to a distance of 1.9(-0.3)(+0.4)kpc, making this the first hydroxyl maser parallax below one milliarcsecond. We also introduce a new method of error analysis for detecting systematic errors in the astrometry. Finally, we compare our trigonometric distances to published phase-lag distances toward these stars and find a good agreement between the two methods.
stars: AGB and post-AGB
agb stars
distance
vera
stars: individual (WX Psc
circumstellar oh masers
masers
astrometry
proper motions
h2o masers
OH 138.0+7.2)
software
pulsars
vlbi astrometry
correlator
techniques:
Astronomy & Astrophysics
Author
G. Orosz
Kagoshima University
H. Imai
Kagoshima University
R. Dodson
University of Western Australia
M. J. Rioja
CSIRO Astronomy and Space Science
University of Western Australia
Observatorio Astronomico Nacional
S. Frey
Konkoly Observatory Hungarian Academy of Sciences
R. A. Burns
Joint Institute for VLBI ERIC
Kagoshima University
S. Etoka
Universitat Hamburg
A. Nakagawa
Kagoshima University
H. Nakanishi
Kagoshima University
JAXA Institute of Space and Astronautical Science
SKA Organization
Y. Asaki
Atacama Large Millimeter-submillimeter Array
National Institutes of Natural Sciences
S. R. Goldman
Keele University
Daniel Tafoya Martinez
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
Chalmers, Earth and Space Sciences, Onsala Space Observatory
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 153 3 119-Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
Infrastructure
Onsala Space Observatory
DOI
10.3847/1538-3881/153/3/119