Skip to content
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Menu
Home
About Us
Resources
Profiles Metrics
Authors Directory
Institutions Directory
Top Authors
Top Institutions
Top Sponsors
AI Digest
Contact Us
Publication Details
AFRICAN RESEARCH NEXUS
SHINING A SPOTLIGHT ON AFRICAN RESEARCH
earth and planetary sciences
VLBI for Gravity Probe B. V. Proper motion and parallax of the guide star, im Pegasi
Astrophysical Journal, Supplement Series, Volume 201, No. 1, Article 5, Year 2012
Notification
URL copied to clipboard!
Description
We present the principal astrometric results of the very long baseline interferometry (VLBI) program undertaken in support of the Gravity Probe B (GP-B) relativity mission. VLBI observations of the GP-B guide star, the RS CVn binary IM Pegasi (HR 8703), yielded positions at 35 epochs between 1997 and 2005. We discuss the statistical assumptions behind these results and our methods for estimating the systematic errors. We find the proper motion of IM Peg in an extragalactic reference frame closely related to the International Celestial Reference Frame 2 (ICRF2) to be -20.83 ± 0.03 ± 0.09masyr -1 in right ascension and -27.27 ± 0.03 ± 0.09masyr -1 in declination. For each component, the first uncertainty is the statistical standard error and the second is the total standard error (SE) including plausible systematic errors. We also obtain a parallax of 10.37 ± 0.07mas (distance: 96.4 ± 0.7pc), for which there is no evidence of any significant contribution of systematic error. Our parameter estimates for the 25day period orbital motion of the stellar radio emission have SEs corresponding to 0.10mas on the sky in each coordinate. The total SE of our estimate of IM Peg's proper motion is 30% smaller than the accuracy goal set by the GP-B project before launch: 0.14masyr -1 for each coordinate of IM Peg's proper motion. Our results ensure that the uncertainty in IM Peg's proper motion makes only a very small contribution to the uncertainty of the GP-B relativity tests. © 2012. The American Astronomical Society. All rights reserved..
Authors & Co-Authors
Ratner, Michael I.
United States, Cambridge
Harvard-smithsonian Center for Astrophysics
Bartel, Norbert
Canada, Toronto
York University
Bietenholz, Michael F.
Canada, Toronto
York University
South Africa, Krugersdorp
Hartebeesthoek Radio Astronomy Observatory
Lebach, D. E.
United States, Cambridge
Harvard-smithsonian Center for Astrophysics
Lestrade, Jean François
France, Paris
Cnrs Centre National de la Recherche Scientifique
Ransom, R. R.
Canada, Toronto
York University
Canada, Kelowna
Okanagan College
Canada, Ottawa
National Research Council Canada
Shapiro, Irwin I.
United States, Cambridge
Harvard-smithsonian Center for Astrophysics
Statistics
Citations: 10
Authors: 7
Affiliations: 6
Identifiers
Doi:
10.1088/0067-0049/201/1/5
ISSN:
00670049
Research Areas
Environmental