HD 45184
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 06h 24m 43.87975s[1] |
| Declination | –28° 46′ 48.4163″[1] |
| Apparent magnitude (V) | 6.37[2] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | G2Va[3] |
| Apparent magnitude (B) | 6.996[2] |
| Apparent magnitude (J) | 5.219[4] |
| Apparent magnitude (H) | 4.962[4] |
| Apparent magnitude (K) | 4.871[4] |
| B−V color index | 0.626±0.007[2] |
| Astrometry | |
| Radial velocity (Rv) | −3.828±0.0003[1] km/s |
| Proper motion (μ) | RA: −165.257[1] mas/yr Dec.: −121.826[1] mas/yr |
| Parallax (π) | 45.5224 ± 0.0320[1] mas |
| Distance | 71.65 ± 0.05 ly (21.97 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.67[2][5] |
| Details | |
| Mass | 1.08±0.04[6] M☉ |
| Radius | 1.05±0.02[1] R☉ |
| Luminosity | 1.178+0.002 −0.001[1] L☉ |
| Surface gravity (log g) | 4.47±0.02[7] cgs |
| Temperature | 5,862+72 −48[1] K |
| Metallicity [Fe/H] | 0.070±0.016[6] dex |
| Rotation | 20.0±0.1 d[6] |
| Rotational velocity (v sin i) | 2.1[7] km/s |
| Age | 3.0+0.7 −1.4[6] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
HD 45184 is a star in the southern constellation of Canis Major. It is a yellow-hued star near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.37.[2] The star is located at a distance of 71.65 light years from the Sun based on parallax.[1] It is drifting closer with a radial velocity of −3.8 km/s.[1]
This object is an ordinary G-type main-sequence star with a stellar classification of G2Va,[3] and it is considered a solar twin.[5] The mass, size, and luminosity of the star are slightly higher than for the Sun, and it has a near solar metallicity – what astronomers term the abundance of elements with higher atomic numbers than helium. The star is around three billion years old and is spinning with a 20-day period.[6] It has a 5.14[9]-year magnetic activity cycle that has a lower amplitude than on the Sun.[7]
Planetary system[]
HD 45184 has a planet around 12 times as massive as Earth that takes 5.88 days to complete an orbit around its host star. This planet was detected using the radial velocity method.[10] It was later confirmed with Spitzer, whereupon a second candidate planet of similar mass was discovered orbiting with a 13.1 day period. The star was observed by Spitzer for a transit of the inner planet, but no event was detected.[11] Both Neptune-like planets have near circular orbits close to the host star.[7]
An infrared excess has been detected using the Multiband Imaging Photometer for Spitzer at a wavelength of 70 μm, making this a debris disk candidate.[12] Based upon blackbody models, it is orbiting 1.0 AU from the host star with a mean temperature of 280 K. There may be an additional, 60 K debris disk orbiting at a distance of 22.89 AU.[13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥12.19+1.06 −1.03 M |