XO-1
Star in the constellation Corona Borealis
From Wikipedia, the free encyclopedia
XO-1 is a magnitude 11 G-type main-sequence star located approximately 530 light-years away[2] in the constellation Corona Borealis. XO-1 has a mass and radius similar to the Sun. In 2006 the extrasolar planet XO-1b was discovered orbiting XO-1 by the transit method using the XO Telescope.[3]
This artist's impression shows a dramatic close-up of the extrasolar planet XO-1b passing in front of a Sun-like star 600 light-years from Earth. The Jupiter-sized planet is in a tight four-day orbit around the star. Credit: NASA, ESA and G. Bacon (STScI) | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Corona Borealis[1] |
| Right ascension | 16h 02m 11.8462s[2] |
| Declination | +28° 10′ 10.420″[2] |
| Apparent magnitude (V) | 11.19 ± 0.03[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G1V[3] |
| Apparent magnitude (B) | 11.85 ± 0.04[3] |
| Apparent magnitude (V) | 11.19 ± 0.03[3] |
| Apparent magnitude (J) | 9.939 ± 0.022[4] |
| Apparent magnitude (H) | 9.601 ± 0.017[4] |
| Apparent magnitude (K) | 9.527 ± 0.015[4] |
| Variable type | Planetary transit variable[3] |
| Astrometry | |
| Radial velocity (Rv) | 2.49±0.32[2] km/s |
| Proper motion (μ) | RA: −17.349(12) mas/yr[2] Dec.: 14.780(15) mas/yr[2] |
| Parallax (π) | 6.1489±0.0136 mas[2] |
| Distance | 530 ± 1 ly (162.6 ± 0.4 pc) |
| Absolute magnitude (MV) | 5.02+0.14 −0.16[5] |
| Details | |
| Mass | 1.027+0.057 −0.061[5] M☉ |
| Radius | 0.94 ± 0.02[6] R☉ |
| Luminosity | 0.86+0.12 −0.10[5] L☉ |
| Surface gravity (log g) | 4.50 ± 0.01[7] cgs |
| Temperature | 5738 ± 65[7] K |
| Metallicity [Fe/H] | −0.06 ± 0.07[7] dex |
| Rotational velocity (v sin i) | 1.1 ± 1.0[7] km/s |
| Age | 1.0+3.1 −0.9[5] Gyr |
| Other designations | |
| Moldoveanu, BD+28 2507, TOI-2021, TIC 236312126, TYC 2041-1657-1, GSC 02041-01657, 2MASS J16021184+2810105[8] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The star XO-1 is named Moldoveanu. The name was selected in the NameExoWorlds campaign by Romania, during the 100th anniversary of the IAU. Moldoveanu is the highest peak in Romania.[9][10][11]
Planetary system
The XO Project is an international team of professional and amateur astronomers which discovered the Jupiter-sized planet orbiting around XO-1. The team, led by Peter R. McCullough of the Space Telescope Science Institute in Baltimore, includes four amateur astronomers from North America and Europe. The planet was confirmed using the Harlan J. Smith Telescope and Hobby-Eberly Telescope at McDonald Observatory of the University of Texas.[3] An independent confirmation of the planet was made by the Wide Angle Search for Planets project.[12] In 2019, the planet was named Negoiu, after Negoiu Peak in Romania.
Further observations with the NICMOS instrument on board the Hubble Space Telescope detected the presence of water vapor, methane, and carbon dioxide in the atmosphere of XO-1b.[13] However an independent reinvestigation of the same data was unable to reproduce these results.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Negoiu | 0.907±0.022 MJ | 0.04914±0.00045 | 3.94150514(20) | <0.019 | 88.84±0.22° | 1.199±0.017 RJ |