XO-2
| Observation data Epoch 2000 Equinox 2000 | |
|---|---|
| Constellation | Lynx[1] |
| XO-2S | |
| Right ascension | 07h 48m 07.4814s[2] |
| Declination | +50° 13′ 03.254″[2] |
| Apparent magnitude (V) | 11.12±0.03[3] |
| XO-2N | |
| Right ascension | 07h 48m 06.468s[4] |
| Declination | +50° 13′ 32.96″[4] |
| Apparent magnitude (V) | 11.18±0.03[3] |
| Characteristics | |
| Spectral type | K0V + K0V[3] |
| Astrometry | |
| Proper motion (μ) | RA: -34.7 ± 2.6[4] mas/yr Dec.: -153.6 ± 2.4[4] mas/yr |
| Parallax (π) | 6.68 ± 0.23 mas[2] |
| Distance | 490 ± 20 ly (150 ± 5 pc) |
| Details | |
| XO-2S | |
| Mass | 0.982 ± 0.034[5] M☉ |
| Radius | 1.02[5] R☉ |
| Temperature | 5399 ± 55 [5] K |
| Metallicity [Fe/H] | 0.39 ± 0.05[5] dex |
| Age | 7.1 ± +2.5 −2.9[5] Gyr |
| XO-2N | |
| Mass | 0.971 ± 0.034[6] M☉ |
| Radius | 0.976+0.024 −0.016[6] R☉ |
| Temperature | 5340 ± 32[3] K |
| Metallicity [Fe/H] | 0.44 ± 0.02[3] dex |
| Age | 6.3 ± 2.4[6] Gyr |
| Other designations | |
| XO-2S: LSPM J0748+5013S, TYC 3413-210-1, GSC 03413-00210, 2MASS J07480748+5013032[7] | |
| XO-2N: LSPM J0748+5013N, TYC 3413-5-1, GSC 03413-00005, 2MASS J07480647+5013328[8] | |
| Database references | |
| SIMBAD | XO-2S |
| XO-2N | |
XO-2 Is a binary star. It consists of two components: XO-2S (Also known as XO-2A) and XO-2N (Also known as XO-2B).[5]
This system is located approximately 490 light-years away[2] from Earth in the Lynx constellation. Both of these stars are slightly cooler than the Sun and are nearly identical to each other. The system has a magnitude of 11 and cannot be seen with the naked eye but is visible through a small telescope. These stars are also notable for their large proper motions.[7][8]
XO-2N and XO-2S have a separation of approximately 4,600 AU.[3]
Planetary systems
One known exoplanet, XO-2Nb (or rarely XO-2Bb), which is classified as a hot Jupiter, was discovered by the XO Telescope using the transit method orbiting XO-2N (XO-2B) in 2007.[3]
Two planets were reported to orbit around XO-2S in 2014 using radial velocity method. One of them is Jupiter-mass and another has a mass comparable to Saturn.[5]
Both stars also show RV-trends, which may indicate the presence of additional long-periodic jovians or brown dwarfs around each of them.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 0.259 ± 0.014 MJ | 0.1344 ±0.0025 | 18.157 ± 0.034 | 0.18 ± 0.035 | — | — |
| c | ≥ 1.37 ± 0.053 MJ | 0.4756 ±0.0087 | 120.8 ± 0.034 | 0.1528 ± 0.01 | — | — |
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.62 ± 0.02 MJ | 0.0369 ±0.002 | 2.61586178 ± 0.00000075 | 0.045 ± 0.024 | 88.7 ± 1.3° | 0.973 ± 0.03 RJ |
See also
References
- ^ Roman, Nancy G. (1987). "Identification of a Constellation From a Position". Publications of the Astronomical Society of the Pacific. 99 (617): 695–699. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Vizier query form
- ^ a b c d Brown, A. G. A; et al. (2016). "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties". Astronomy and Astrophysics. 595. A2. arXiv:1609.04172. Bibcode:2016A&A...595A...2G. doi:10.1051/0004-6361/201629512.Gaia Data Release 1 catalog entry
- ^ a b c d e f g Burke, Christopher J.; et al. (2007). "XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary". The Astrophysical Journal. 671 (2): 2115–2128. arXiv:0705.0003. Bibcode:2007ApJ...671.2115B. doi:10.1086/523087.
- ^ a b c d Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. Vizier catalog entry
- ^ a b c d e f g h Desidera, S.; et al. (2014). "The GAPS programme with HARPS-N at TNG. IV. A planetary system around XO-2S". Astronomy and Astrophysics. 567 (6). L6. arXiv:1407.0251. Bibcode:2014A&A...567L...6D. doi:10.1051/0004-6361/201424339.
- ^ a b c Fernandez, Jose M.; et al. (2009). "The Transit Light Curve Project. XII. Six Transits of the Exoplanet XO-2b". The Astronomical Journal. 137 (6): 4911–4916. arXiv:0903.2687. Bibcode:2009AJ....137.4911F. doi:10.1088/0004-6256/137/6/4911.
- ^ a b "TYC 3413-210-1". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-28.
- ^ a b "TYC 3413-5-1". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-28.
- ^ Narita, Norio; et al. (2011). "XO-2b: a Prograde Planet with a Negligible Eccentricity and an Additional Radial Velocity Variation". Publications of the Astronomical Society of Japan. 63 (6): L67–L71. arXiv:1110.6136. Bibcode:2011PASJ...63L..67N. doi:10.1093/pasj/63.6.l67.
- ^ Sing, D. K.; et al. (2011). "Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry". Astronomy and Astrophysics. 527. A73. arXiv:1008.4795. Bibcode:2011A&A...527A..73S. doi:10.1051/0004-6361/201015579.
External links
- NASA PlanetQuest: Planet race heats up: 1 month, 32 discoveries
- "XO-2". Exoplanets. Retrieved 2009-04-28.
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