HD 45184
Star in the constellation Canis Major
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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.[1] The star is located at a distance of 71.4 light years from the Sun based on parallax.[2] It is drifting closer with a radial velocity of −3.8 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canis Major[1] |
| Right ascension | 06h 24m 43.87951s[2] |
| Declination | −28° 46′ 48.4157″[2] |
| Apparent magnitude (V) | 6.37[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | G2Va[3] |
| Apparent magnitude (B) | 6.996[1] |
| 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[1] |
| Astrometry | |
| Radial velocity (Rv) | −3.85±0.12[2] km/s |
| Proper motion (μ) | RA: −165.122[2] mas/yr Dec.: −121.852[2] mas/yr |
| Parallax (π) | 45.6782±0.0166 mas[2] |
| Distance | 71.40 ± 0.03 ly (21.892 ± 0.008 pc) |
| Absolute magnitude (MV) | 4.67[1][5] |
| Details | |
| Mass | 1.08±0.04[6] M☉ |
| Radius | 1.05±0.04[7] R☉ |
| Luminosity | 1.17±0.03[7] L☉ |
| Surface gravity (log g) | 4.47±0.02[8] cgs |
| Temperature | 5,854±107[7] K |
| Metallicity [Fe/H] | 0.070±0.016[6] dex |
| Rotation | 20.0±0.1 d[6] |
| Rotational velocity (v sin i) | 2.1[8] km/s |
| Age | 3.0+0.7 −1.4[6] Gyr |
| Other designations | |
| CD−29°2981, GJ 3394, HD 45184, HIP 30503, HR 2318, SAO 171711, PPM 250356[9] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
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[10]-year magnetic activity cycle that has a lower amplitude than on the Sun.[8]
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.[11] 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.[12] Both Neptune-like planets have near circular orbits close to the host star.[8]
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.[13] 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.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥12.19+1.06 −1.03 M🜨 |
0.0644+0.0020 −0.0021 |
5.8854±0.0003 | 0.07±0.05 | — | — |
| c | ≥8.81+1.09 −1.02 M🜨 |
0.1100+0.0034 −0.0036 |
13.1354+0.0026 −0.0025 |
0.07+0.07 −0.05 |
— | — |