A Mass for the Extrasolar Planet Gliese 876[CLC]b[/CLC] Determined from [ITAL]Hubble Space Telescope[/ITAL] Fine Guidance Sensor 3 Astrometry and High-Precision Radial Velocities
| Autor: | G. W. Marcy, T. Forveille, X. Delfosse, William H. Jefferys, William Spiesman, M. Mayor, E. P. Nelan, C. Perrier, Barbara McArthur, Bertrand Goldman, R. P. Butler, G. F. Benedict |
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| Rok vydání: | 2002 |
| Předmět: |
Physics
Proper motion Doppler spectroscopy Astronomy and Astrophysics Astrophysics Astrometry Position angle Exoplanet Space and Planetary Science Planet Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Eccentricity (mathematics) Planetary mass Astrophysics::Galaxy Astrophysics |
| Zdroj: | The Astrophysical Journal. 581:L115-L118 |
| ISSN: | 1538-4357 0004-637X |
| Popis: | We report the first astrometrically determined mass of an extrasolar planet, a companion previously detected by Doppler spectroscopy. Radial velocities first provided an ephemeris with which to schedule a significant fraction of the {\it HST} observations near companion peri- and apastron. The astrometry residuals at these orbital phases exhibit a systematic deviation consistent with a perturbation due to a planetary mass companion. Combining {\it HST} astrometry with radial velocities, we solve for the proper motion, parallax, perturbation size, inclination, and position angle of the line of nodes, while constraining period, velocity amplitude, longitude of periastron, and eccentricity to values determined from radial velocities. We find a perturbation semi-major axis and inclination, $\alpha$ = 0.25 $\pm$ 0.06 mas, $i$ = 84\arcdeg $\pm$6\arcdeg, and Gl 876 absolute parallax, $\pi_{abs}= 214.6 \pm$ 0.2 mas. Assuming that the mass of the primary star is $M_* = 0.32M_{\sun}$, we find the mass of the planet, Gl 876b, $M_b = 1.89\pm0.34M_{Jup}$. |
| Databáze: | OpenAIRE |
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