HD 50554
Star in the constellation Gemini
From Wikipedia, the free encyclopedia
HD 50554 is a single,[7] Sun-like[8] star with an exoplanetary companion in the northern constellation of Gemini. It has an apparent visual magnitude of +6.84,[1] which makes it a 7th magnitude star; it is not visible to the naked eye, but can be viewed with binoculars or a telescope. The system is located at a distance of 101 light-years (31 parsecs) from the Sun based on parallax, but is drifting closer with a radial velocity of −4 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Gemini[1] |
| Right ascension | 06h 54m 42.82615s[2] |
| Declination | +24° 14′ 44.0057″[2] |
| Apparent magnitude (V) | +6.84[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | F8V[3] |
| B−V color index | 0.582±0.008[1] |
| Astrometry | |
| Radial velocity (Rv) | −3.77±0.13[2] km/s |
| Proper motion (μ) | RA: −35.839 mas/yr[2] Dec.: −96.668 mas/yr[2] |
| Parallax (π) | 32.1855±0.0242 mas[2] |
| Distance | 101.34 ± 0.08 ly (31.07 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.46[1] |
| Details | |
| Mass | 1.06±0.03[4] M☉ |
| Radius | 1.07±0.03[4] R☉ |
| Luminosity | 1.37±0.01[4] L☉ |
| Surface gravity (log g) | 4.4±0.04[4] cgs |
| Temperature | 6,036±52[4] K |
| Metallicity [Fe/H] | 0.05±0.06[5] dex |
| Rotational velocity (v sin i) | 2.3[5] km/s |
| Age | 3.3±1.4 Gyr[4] 2.1±1.6[5] Gyr |
| Other designations | |
| BD+24°1451, GC 9043, HD 50554, HIP 33212, SAO 78855, GSC 01894-01961[6] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
This is a yellow-white hued F-type main-sequence star with a stellar classification of F8V.[3] Age estimates put it at around 2–3 billion years old. It has a Sun-like metallicity a low level of chromospheric activity[9] and is spinning with a projected rotational velocity of 2.3 km/s.[5] The star has a slightly higher mass and larger radius than the Sun. It is radiating 137% of the luminosity of the Sun from its photosphere at an effective temperature of 6,036 K.[4]
Planetary system
In 2001, a giant planet was announced by the European Southern Observatory, who used the radial velocity method.[10][9] The discovery was formally published in 2002 using observations from the Lick and Keck telescopes.[3] In 2023, the inclination and true mass of HD 50554 b were determined via astrometry.[11] Two more inner planet candidates, both super-Earths, have been detected by TESS; they were validated by a 2026 study.[12]
An infrared excess indicates a debris disk is orbiting the star at a distance of 45 AU with a half-width of 4 AU. This may be an analog of the Kuiper belt at an earlier stage of its evolution, which suggests a Neptune-like planet could be orbiting at its inner edge.[8]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| c[12] | <5.3 M🜨 | 0.066+0.009 −0.018 |
5.969362(20) | — | — | 1.31±0.06 R🜨 |
| d[12] | <10.4 M🜨 | 0.168+0.028 −0.065 |
28.06940(40) | — | — | 1.41+0.14 −0.09 R🜨 |
| b[11] | 5.85+0.9 −0.52 MJ |
2.339+0.03 −0.029 |
1,238+7 −8 |
0.482±0.015 | 61±12 or 119±12° | — |
| Disk[8] | 45 AU | — | — | |||