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|- ! style="background-color: #FFFFC0;" colspan="2" | Characteristics |- | Spectral type | ? (primary)/M (b)〔 |- style="vertical-align: top;" | Apparent magnitude (infrared, I band) | 15.61 (system)〔 |- style="vertical-align: top;" | Variable type | Eclipsing binary |- ! style="background-color: #FFFFC0;" colspan="2" | Binary orbit |- style="vertical-align: top;" | Period (P) | 7.269〔(A planet-sized transiting star around OGLE-TR-122. Accurate mass and radius near the hydrogen-burning limit ), F. Pont, C. H. F. Melo, F. Bouchy, S. Udry, D. Queloz, M. Mayor, and N. C. Santos, ''Astronomy and Astrophysics'' 433, #2 (April 11, 2005), pp. L21–L24.〕 days |- style="vertical-align: top;" | Eccentricity (e) | 0.205 |- style="vertical-align: top;" | Inclination (i) | 88–90° OGLE-TR-122 is a binary stellar system containing one of the smallest main-sequence stars whose radius has been measured. It was discovered when the Optical Gravitational Lensing Experiment (OGLE) survey observed the smaller star eclipsing the larger primary. The orbital period is approximately 7.3 days. The system's primary is thought to resemble the Sun.〔 The smaller star, OGLE-TR-122B, is estimated to have a radius around 0.12 solar radii, or around 20% larger than Jupiter's, and a mass of around 0.1 solar masses, or approximately 100 times Jupiter's. This makes its average density approximately 50 times the Sun's〔〔(Newfound Star Smaller than Some Planets ), Robert Roy Britt, space.com, accessed on line May 16, 2007.〕 or over 80 times the density of water. OGLE-TR-122b's mass is close to the lowest possible mass for a hydrogen-fusing star, estimated to be around 0.07 or 0.08 solar masses.〔(Theory of Low-Mass Stars and Substellar Objects ), Gilles Chabrier and Isabelle Baraffe, ''Annual Review of Astronomy and Astrophysics'' 38 (2000), pp. 337–377.〕 The observed transit provides the first direct evidence for a star with a radius comparable to Jupiter's.〔 File:Brightness «Dip» and Velocity Variations of OGLE-TR-122.jpg|Brightness «Dip» and Velocity Variations of OGLE-TR-122. ==See also== * OGLE-TR-123 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「OGLE-TR-122」の詳細全文を読む スポンサード リンク
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