HD 167042
Star in the constellation Draco
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HD 167042 is a star with an orbiting exoplanet in the northern constellation of Draco. With an apparent visual magnitude of +5.97,[3] the star is dimly visible to the naked eye. It is located at a distance of 162 light years based on parallax measurements,[2] but it is drifting closer with a radial velocity of −18 km/s.[7] HD 167042 has a relatively large proper motion, traversing the celestial sphere at an angular rate of 0.270″ yr−1.[11]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Draco[1] |
| Right ascension | 18h 10m 31.640s[2] |
| Declination | +54° 17′ 11.59″[2] |
| Apparent magnitude (V) | +5.97[3] |
| Characteristics | |
| Evolutionary stage | red giant branch[4][2] |
| Spectral type | K1 III[5] or K1 IV[3] |
| U−B color index | +0.716[6] |
| B−V color index | +0.934[6] |
| Astrometry | |
| Radial velocity (Rv) | −17.88[7] km/s |
| Proper motion (μ) | RA: +107.630 mas/yr[2] Dec.: +247.345 mas/yr[2] |
| Parallax (π) | 20.1313±0.0293 mas[2] |
| Distance | 162.0 ± 0.2 ly (49.67 ± 0.07 pc) |
| Absolute magnitude (MV) | 2.48[8] |
| Details[9] | |
| Mass | 1.4696±0.0532 M☉ |
| Radius | 4.4947±0.0576 R☉ |
| Luminosity | 10.717+0.924 −0.850 L☉ |
| Surface gravity (log g) | 3.3008±0.0050 cgs |
| Temperature | 4,926±79 K |
| Metallicity [Fe/H] | +0.093±0.061 dex |
| Rotational velocity (v sin i) | 0.68[7] km/s |
| Age | 7.413±0.829 Gyr |
| Other designations | |
| BD+54°1950, GC 24820, HD 167042, HIP 89017, HR 6817, SAO 30784, PPM 36415, LTT 15382, Wolf 1415[10] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
The spectrum of HD 167042 presents as an evolved K-type giant star, an orange giant, with a stellar classification of K1 III.[5] The position of this star on the H-R diagram is at the base of the red giant branch.[4] When this star was a main sequence, it was white-hued mid to late A-type star based on its mass. It shows no significant magnetic activity in its chromosphere.[8] The star has 1.88 times the mass of the Sun and has expanded to 4.49 times the Sun's radius. It is radiating 10.7 times the luminosity of the Sun from its photosphere at an effective temperature of 4,926 K.[9]
Planetary system
On 28 November 2007, a preprint of the discovery of the exoplanet HD 167042 b was posted to the arXiv server. The peer reviewed paper was then published in The Astrophysical Journal on 1 March 2008.[8] The discovery was later independently confirmed.[12] There is a long-period radial velocity trend, which might indicate the presence of a second substellar companion.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.397+0.031 −0.044 MJ |
1.220±0.001 | 417.67+0.43 −0.41 |
0.010+0.033 −0.004 |
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