Key parameters at a glance
- A radius of 5.02 Earth radii
- A mass of 22.25 Earth masses
- Surface gravity around 0.88 g
- An orbital period of 4.085 days
- Semi-major axis 0.0500 AU
- Distance from Earth 122.17 light-years
- Earth Similarity Index 0.475
- Travel time at Voyager 1 speed 2,154,460 years
Context from the literature
HD 47186 b is a “hot Neptune” extrasolar planet located approximately 123 light years away in the constellation of Canis Major, orbiting the star HD 47186. This planet has a minimum mass of 22.78 times that of Earth and orbits very close to the star at a similar distance from the star as 51 Pegasi b is from 51 Pegasi. As in consequence, it takes 4.0845 days to complete an orbit with an eccentricity of 0.038, which is similar to the 5.66 year-period planet HD 70642 b.
Excerpted from Wikipedia · full article
1 sibling around HD 47186
HD 47186 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| HD 47186 b this | Neptune-like | 5.02 | 22.25 | 4.085 | — | 2008 |
| HD 47186 c | Gas Giant | 13.00 | 111.42 | 1,353.600 | — | 2008 |
HD 47186 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#380of 574
top 66.0%
This planet
5.02R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | HD 47186 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 5.02 | 11.21 |
| Mass (M⊕) | 1.00 | 22.25 | 317.83 |
| Density (g/cm³) | 5.51 | 0.97 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.88 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 22.248 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 47186
HIP
HIP 31540
TIC
TIC 101145648
Gaia DR2
Gaia DR2 2919760965879179136
Gaia DR3
Gaia DR3 2919760965880144384
System
HD 47186
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.08 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0500 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.475
0 = alien, 1 = Earth-identical
Discovery Paper
Primary reference
Bouchy et al. 2009Instrument
HARPS Spectrograph
Publication
2009-03
Observation locale
Ground
Discovery cohort
Planets confirmed in 2008 at La Silla Observatory (12 shown).
Host System: HD 47186
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,657 K — cooler than the Sun (5,778 K)
Estimated Age
6.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.080 R☉
Stellar Mass
0.960 M☉
Metallicity [Fe/H]
0.24
Extended Stellar Properties
Surface gravity (log g)
4.360 dex
Stellar density
1.057 g/cm³
Systemic radial velocity
4.30 km/s
Rotational v·sin i
2.20 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
26.668 mas
Total Proper Motion
263.833 mas/yr
PM Right Ascension
21.59 mas/yr
PM Declination
-262.95 mas/yr
Galactic Cartesian (pc)
x = -0.139 · y = 0.875 · z = -0.464
Equatorial (J2000)
RA 99.03672° · Dec -27.62343°
Galactic ℓ, b
236.504° · -15.307°
Ecliptic λ, β
102.679° · -50.666°
HTM-20 index
1739693926
Observation Record
Photometric series
1
RV measurements
1
Stellar spectra
2
Archive notes
1
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