VLBA SiO maser observations of the OH/IR star OH 44.8-2.3: Magnetic field and morphology

N. Amiri, W. H.T. Vlemmings, A. J. Kemball, H. J. Van Langevelde

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We report on Very Long Baseline Array SiO maser observations of the OH/IR star OH 44.8 - 2.3. The observations show that the maser features form a ring located at a distance of 5.4 AU around the central star. The masers show high fractional linear polarization up to 100%. The polarization vectors are consistent with a dipole field morphology. Additionally, we report a tentative detection of circular polarization of 7% for the brightest maser feature. This indicates a magnetic field of 1.5 ± 0.3 G. The SiO masers and the 1612 MHz OH masers suggest a mildly preferred outflow direction in the circumstellar environment of this star. The observed polarization is consistent with magnetic field structures along the preferred outflow direction. This could indicate the possible role of the magnetic fields in shaping the circumstellar environment of this object.

Original languageEnglish (US)
Title of host publicationCosmic Masers - from OH to H0
EditorsRoy S. Booth, Elizabeth M. L. Humphreys, Wouter H.T. Vlemmings
Number of pages5
StatePublished - Jul 2012
Externally publishedYes

Publication series

NameProceedings of the International Astronomical Union
ISSN (Print)1743-9213
ISSN (Electronic)1743-9221


  • Magnetic Fields
  • Maser
  • Polarization
  • Stars

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Astronomy and Astrophysics
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health
  • Space and Planetary Science


Dive into the research topics of 'VLBA SiO maser observations of the OH/IR star OH 44.8-2.3: Magnetic field and morphology'. Together they form a unique fingerprint.

Cite this