OGLE-TR-122

OGLE-TR-122
	; TheEarth-Moonorbit,Saturn,OGLE-TR-122b,Jupiter,andother objects,to scale.
Observation data; EpochJ2000.0EquinoxJ2000.0(ICRS)
Constellation	Carina
Right ascension	11h06m51.99s
Declination	−60° 51′ 45.7″
Characteristics
Spectral type	?(primary)/M (b)
Apparent magnitude(I)	15.61 (system)
Variable type	Eclipsing binary
Orbit
Period(P)	7.26867d
Eccentricity(e)	0.205 ± 0.008
Inclination(i)	88–90°
Periastronepoch(T)	JD2452342.41 ± 0.02
Argument of periastron(ω); (secondary)	99.2 ± 0.8°
Semi-amplitude(K1); (primary)	9.642 ± 0.088 km/s
Details
OGLE-TR-122A
Mass	0.98 ± 0.14M☉
Radius	1.05+0.20; −0.09R☉
Surface gravity(logg)	3.9 ± 0.5cgs
Temperature	5700 ± 300K
Metallicity[Fe/H]	0.15 ± 0.36dex
Rotational velocity(vsini)	5.7 ± 0.6 km/s
OGLE-TR-122B
Mass	0.092 ± 0.009M☉
Radius	0.120+0.024; −0.013R☉
Other designations
	V817Car
Database references
SIMBAD	data

OGLE-TR-122is abinary stellar systemcontaining one of the smallestmain-sequence starswhoseradiushas been measured. It was discovered when theOptical 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 theSun.^[2]

OGLE-TR-122B

The smaller star,OGLE-TR-122B,is estimated to have aradiusaround 0.12solar radii,or around 20% larger thanJupiter's, and amassof around 0.1solar masses,or approximately 100 times Jupiter's. This makes its averagedensityapproximately 50 times the Sun's^[2]^[3]or over 80 times the density ofwater.OGLE-TR-122b's mass is close to the lowest possible mass for ahydrogen-fusing star, estimated to be around 0.07 or 0.08 solar masses.^[4]The observed transit provides the first direct evidence for a star with a radius comparable to Jupiter's.^[2]

Brightness «Dip» and Velocity Variations of OGLE-TR-122.

References

^^a ^b ^cThe Optical Gravitational Lensing Experiment. Additional Planetary and Low-Luminosity Object Transits from the OGLE 2001 and 2002 Observational Campaigns,A. Udalski, G. Pietrzynski, M. Szymanski, M. Kubiak, K. Zebrun, I. Soszynski, O. Szewczyk, and L. Wyrzykowski,Acta Astronomica53(June 2003), pp. 133–149.
^^a ^b ^c ^d ^e ^fPont, F.; Melo, C. H. F.; Bouchy, F.; Udry, S.; Queloz, D.; Mayor, M.; Santos, N. C. (2005). "A planet-sized transiting star around OGLE-TR-122".Astronomy and Astrophysics.433(2): L21.arXiv:astro-ph/0501611.Bibcode:2005A&A...433L..21P.doi:10.1051/0004-6361:200500025.S2CID 14799999.
^Newfound Star Smaller than Some Planets,Robert Roy Britt, space, accessed on line May 16, 2007.
^Chabrier, Gilles; Baraffe, Isabelle (2000). "Theory of Low-Mass Stars and Substellar Objects".Annual Review of Astronomy and Astrophysics.38:337–377.arXiv:astro-ph/0006383.Bibcode:2000ARA&A..38..337C.doi:10.1146/annurev.astro.38.1.337.S2CID 59325115.

[aa-1] The Optical Gravitational Lensing Experiment. Additional Planetary and Low-Luminosity Object Transits from the OGLE 2001 and 2002 Observational Campaigns,A. Udalski, G. Pietrzynski, M. Szymanski, M. Kubiak, K. Zebrun, I. Soszynski, O. Szewczyk, and L. Wyrzykowski,Acta Astronomica53(June 2003), pp. 133–149.

[xit-2] Pont, F.; Melo, C. H. F.; Bouchy, F.; Udry, S.; Queloz, D.; Mayor, M.; Santos, N. C. (2005). "A planet-sized transiting star around OGLE-TR-122".Astronomy and Astrophysics.433(2): L21.arXiv:astro-ph/0501611.Bibcode:2005A&A...433L..21P.doi:10.1051/0004-6361:200500025.S2CID 14799999.

[3] Newfound Star Smaller than Some Planets,Robert Roy Britt, space, accessed on line May 16, 2007.

[4] Chabrier, Gilles; Baraffe, Isabelle (2000). "Theory of Low-Mass Stars and Substellar Objects".Annual Review of Astronomy and Astrophysics.38:337–377.arXiv:astro-ph/0006383.Bibcode:2000ARA&A..38..337C.doi:10.1146/annurev.astro.38.1.337.S2CID 59325115.

[1]

[2]

[3]

[4]

OGLE-TR-122B

See also

References