The HD 202206 Exoplanetary System: Companion Masses and (in)Stability
Abstract
Correia et al. (2005) first reported a Doppler spectroscopy discovery of the exoplanetary companions to HD 202206, obtaining values Mb sin i=17.4MJup and Mc sin i=2.44MJup. The title of their paper ”A pair of planets around HD 202206 or a circumbinary planet?” indicated a need for astrometry capable of measuring inclination. Hence, we included this system in a Hubble Space Telescope Fine Guidance Sensor (FGS) astrometry proposal to measure the architectures of several promising candidate systems, all relatively nearby with companion M sin i values and periods suggesting measurable astrometric amplitudes.Simultaneous modeling of thirty-one FGS observation sets obtained over three years and the Correia et al. radial velocities yields a parallax and preliminary mass estimates for HD 202206 b and HD 202206 c.Using either the original Correia et al. (2005) or the Couetdic et al. (2010) M sin i values, HD 202206 fails the stability criteria derived by Petrovich (2015). Thus far our astrometric masses have done nothing to ameliorate that situation. A combination of additional RV measurements and Gaia astrometry should further illuminate our understanding of the dynamics of this interesting system.ReferencesCorreia et al. (2005) A&A, 440, 751Couetdic et al. (2010) A&A, 519, A10Petrovich (2015) ApJ, 808, 120
- Publication:
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American Astronomical Society Meeting Abstracts #229
- Pub Date:
- January 2017
- Bibcode:
- 2017AAS...22924515B