HD 10647
Star in the constellation Eridanus
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HD 10647 (q1 Eridani) is a 6th-magnitude yellow-white dwarf star, 57 light-years away in the constellation of Eridanus. The star is visible to the unaided eye under very dark skies. It is slightly hotter and more luminous than the Sun, and at 700 million years old, it is also younger. An extrasolar planet was discovered orbiting this star in 2003.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Eridanus[1] |
| Right ascension | 01h 42m 29.3145s[2] |
| Declination | −53° 44′ 26.991″[2] |
| Apparent magnitude (V) | +5.52[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | F9V[4] |
| B−V color index | 0.551[3] |
| Astrometry | |
| Radial velocity (Rv) | 27.64±0.12[2] km/s |
| Proper motion (μ) | RA: 166.041(34) mas/yr[2] Dec.: −105.496(46) mas/yr[2] |
| Parallax (π) | 57.6409±0.0453 mas[2] |
| Distance | 56.58 ± 0.04 ly (17.35 ± 0.01 pc) |
| Absolute magnitude (MV) | 4.31[1] |
| Details | |
| Mass | 1.15+0.01 −0.02[5] M☉ |
| Radius | 1.10±0.02[4] R☉ |
| Luminosity | 1.41[4] L☉ |
| Surface gravity (log g) | 4.55±0.02[5] cgs |
| Temperature | 6,207±11[5] K |
| Metallicity [Fe/H] | −0.027±0.008[5] dex |
| Rotation | 10±3[4] |
| Rotational velocity (v sin i) | 4.9[4] km/s |
| Age | 0.70+0.30 −0.24[5] Gyr |
| Other designations | |
| q1 Eridani, 5 G. Eridani, CPD−54°365, GJ 3109, HIP 7978, HR 506, SAO 232501[6] | |
| Database references | |
| SIMBAD | data |
There is a companion star lying at an angular separation of 35.8'.[7] It is a red dwarf with a spectral type of M4.0Ve.[8]
Planetary system
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In 2003, Michel Mayor's team announced the discovery of a new planet, HD 10647 b, in Paris at the XIX IAP Colloquium Extrasolar Planets: Today & Tomorrow.[10] The Anglo-Australian Planet Search team initially did not detect the planet in 2004,[11] though a solution was made by 2006.[12] The CORALIE data was finally published in 2013.[4]
The IRAS infrared space telescope detected an excess of infrared radiation from the star, indicating a possible circumstellar disk.[13] Out of the 300 nearest Sun-like stars, the disk has the highest fractional luminosity out of all of them.[14] It is unusually bright, but not unusually massive; the lower bound of the mass is 8 times that of the Earth.[14]
The inclination of the disk is relatively high,[15] and the disk is asymmetrical, being more extended in the northeast direction than the southwest.[14] It extends from 34 astronomical units (AU) at the inner edge to 134 AU at the outer edge. The inner edge is sharp, suggesting the existence of a planet that carved out the edge. HD 10647 b, with a semimajor axis of about 2 AU, is too far to be responsible. However, other potential planets may be responsible for this feature.[14]
If HD 10647 b shares the same orbital inclination as the disk (76.7°±1.0°), its mass should be about 1.07 Jupiter masses, close to its minimum mass of 0.90 Jupiter masses.[16]
There is some evidence for an additional, warm asteroid belt-like component further in, at 3 to 10 AU away from the star.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.07±0.05 MJ | 2.02±0.01 | 991.90±1.45 | 0.37±0.03 | — | — |
| Dust disk | 3–10 AU | — | — | |||
| Dust disk | 34–134 AU | 76.1±1.0° | — | |||