The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission

Details The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission

Aug 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005jrasc..99q.130l&link_type=abstract

Journal of the Royal Astronomical Society of Canada, Vol. 99, No. 4, p.130

Astronomy and Astrophysics

Astronomy

Scientific paper

We have observed the quasar 3C454.3 at 3.6 cm with a VLBI array of 12 or more stations about four times per year since 1997 in support of the NASA-Stanford Gravity Probe B mission (GP-B). GP-B is designed to measure the geodetic and frame-dragging effects predicted by general relativity via the measurement of the precessions of four gyroscopes in a drag-free orbit about the Earth. A "guide star," HR 8703 (IM Pegasi), serves as the positional reference for the GP-B spacecraft relative to which the precessions are measured. The quasar 3C454.3, in turn, serves as a distant extragalactic source relative to which the motions of HR 8703 can be measured in an inertial frame. Our mission requirement is to determine the proper motion of HR 8703 relative to an inertial frame with standard error < 0.15 mas yr-1. Structural changes in 3C454.3 over the course of our several years of observations could have a significant impact on the astrometric accuracy that we can attain. In this talk I will discuss the degree of stability of the structure of 3C454.3 over 31 epochs of observations, focus on some observed structural changes, and examine the effects of these changes on our astrometric results for HR 8703.

Affiliated with

Also associated with

No associations

Rating

The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Quasar 3C454.3: An Extragalactic Reference Source for the Gravity Probe B Mission will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-856488