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]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Lynx[1] |
XO-2S | |
Right ascension | 07h 48m 07.4814s[2] |
Declination | +50° 13′ 03.2578″[2] |
Apparent magnitude (V) | 11.12±0.03[3] |
XO-2N | |
Right ascension | 07h 48m 06.4726s[4] |
Declination | +50° 13′ 32.9211″[4] |
Apparent magnitude (V) | 11.18±0.03[3] |
Characteristics | |
Spectral type | K0V + K0V[3] |
Astrometry | |
XO-2S | |
Proper motion (μ) | RA: −29.317±0.063[2] mas/yr Dec.: −154.398±0.044[2] mas/yr |
Parallax (π) | 6.5765 ± 0.0411 mas[2] |
Distance | 496 ± 3 ly (152.1 ± 1.0 pc) |
XO-2N | |
Proper motion (μ) | RA: −29.731±0.083[4] mas/yr Dec.: −154.272±0.050[4] mas/yr |
Parallax (π) | 6.4539 ± 0.0603 mas[4] |
Distance | 505 ± 5 ly (155 ± 1 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 |
This system is located approximately 500 light-years away 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]
There are two known exoplanets orbiting XO-2N. 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] and XO-2Nc was discovered in 2015 using the radial velocity method.[9][10]
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 |
c | 1.8 MJ | — | >6200 | — | — | — |
Constellation of Lynx | |||||||||||||
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