Circumstellar H2O maser emission associated with four late-type stars

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163023· OSTI ID:5413336

Johnston, K J; Spencer, J H; Bowers, P F

The positions and structure of H2O maser associated with four long-period stars were measured using the VLA, and the results are discussed. The four stars observed were: RX Boo; R Aq1; RR Aq1; and NML Cyg. The spatial resolution of the VLA measurements was 0.07 arcsec. The H2O maser emission features appear as unresolved knots distributed over an area of no more than 0.4 arcsec. The velocity and spatial characteristics of the maser regions in R Aq1 and RR Aq1 were found to change considerably over time. The estimated sizes of the H2O maser emission were 8 x 10 to the 14th for RX Boo, R Aq1, and RR Aq1. The supergiant star NML Cyg had the largest maser region (10 to the 16th) which is comparable to that of VY CMa. The positional accuracy for individual maser features ranged between 0.03 and 0.09 arcsec. However, the precise location of the maser emission relative to the stellar photocenter did not fit the velocity and spatial distributions of the emission and therefore may be inappropriate as a standard for comparisons of stellar reference frames. 20 references

• Research Organization: US Navy, E. O. Hulburt Center for Space Research, Washington, DC
• OSTI ID: 5413336
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 290; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
ASTRONOMY
COSMIC RADIO SOURCES
ELECTRONIC EQUIPMENT
EQUIPMENT
INTERFEROMETRY
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
RADIAL VELOCITY
RADIOASTRONOMY
STARS
STELLAR RADIATION
VELOCITY