True mass

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The term true mass is synonymous with the term mass, but is used in astronomy to differentiate the measured mass of a planet from the lower limit of mass usually obtained from radial velocity techniques.[1] Methods used to determine the true mass of a planet include measuring the distance and period of one of its satellites,[2] advanced astrometry techniques that use the motions of other planets in the same star system,[1] combining radial velocity techniques with transit observations (which indicate very low orbital inclinations),[3] and combining radial velocity techniques with stellar parallax measurements (which also determine orbital inclinations).[4]

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  1. ^ a b "McDonald Observatory astronomers discover Neptune-sized planet with Hobby-Eberly Telescope". University of Texas at Austin. 31 August 2004. Retrieved 2007-09-04. [dead link]
  2. ^ Brown, Michael E.; Schaller, Emily L. (15 June 2007). "The Mass of Dwarf Planet Eris". Science. 316 (5831): 1585. Bibcode:2007Sci...316.1585B. PMID 17569855. doi:10.1126/science.1139415. 
  3. ^ "How do we know the density of some extrasolar planets?". Curious About Astronomy?. Retrieved 2007-09-08. [dead link]
  4. ^ Han, Inwoo; Black, David C.; Gatewood, George (2001). "Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions". The Astrophysical Journal Letters. 548 (1): L57–L60. Bibcode:2001ApJ...548L..57H. doi:10.1086/318927.