DOI | Trouver le DOI : https://doi.org/10.1088/0067-0049/201/1/5 |
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Auteur | Rechercher : Ratner, M.I.; Rechercher : Bartel, N.; Rechercher : Bietenholz, M.F.; Rechercher : Lebach, D.E.; Rechercher : Lestrade, J.-F.; Rechercher : Ransom, R.R.1; Rechercher : Shapiro, I.I. |
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Affiliation | - Conseil national de recherches du Canada. Institut Herzberg d'astrophysique du CNRC
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Format | Texte, Article |
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Résumé | 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.. |
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Date de publication | 2012 |
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Dans | |
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Langue | anglais |
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Publications évaluées par des pairs | Oui |
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Numéro NPARC | 21269335 |
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Exporter la notice | Exporter en format RIS |
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Signaler une correction | Signaler une correction (s'ouvre dans un nouvel onglet) |
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Identificateur de l’enregistrement | f630f790-b520-4be6-9b54-00ec15d303d8 |
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Enregistrement créé | 2013-12-12 |
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Enregistrement modifié | 2020-04-21 |
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