Key parameters at a glance
- A radius of 3.13 Earth radii
- A mass of 9.96 Earth masses
- Surface gravity around 1.02 g
- An orbital period of 53.753 days
- Semi-major axis 0.2554 AU
- Distance from Earth 92.08 light-years
- Earth Similarity Index 0.625
- Travel time at Voyager 1 speed 1,623,751 years
1 sibling around HD 13808
HD 13808 c 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 13808 b | Sub-Neptune | 3.35 | 11.20 | 14.182 | — | 2021 |
| HD 13808 c this | Sub-Neptune | 3.13 | 9.96 | 53.753 | — | 2021 |
HD 13808 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#406of 1978
top 20.5%
This planet
3.13R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HD 13808 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.13 | 11.21 |
| Mass (M⊕) | 1.00 | 9.96 | 317.83 |
| Density (g/cm³) | 5.51 | 1.78 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.02 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 9.960 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 13808
HIP
HIP 10301
TIC
TIC 220022156
Gaia DR2
Gaia DR2 4743692151804240896
Gaia DR3
Gaia DR3 4743692151804240896
System
HD 13808
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 53.75 Earth days (14.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.2554 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.625
0 = alien, 1 = Earth-identical
Discovery Paper
Primary reference
Ahrer et al. 2021Instrument
HARPS Spectrograph
Publication
2021-02
Observation locale
Ground
Discovery cohort
Planets confirmed in 2021 at La Silla Observatory (12 shown).
Host System: HD 13808
Spectral Class
K-type orange
Effective Temperature
5,035 K — cooler than the Sun (5,778 K)
Estimated Age
7.20 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.781 R☉
Stellar Mass
0.771 M☉
Metallicity [Fe/H]
-0.21
Extended Stellar Properties
Surface gravity (log g)
4.576 dex
Stellar density
2.458 g/cm³
Systemic radial velocity
40.90 km/s
Rotational v·sin i
2.00 km/s
Rotation period
38.99 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
35.394 mas
Total Proper Motion
112.280 mas/yr
PM Right Ascension
-107.92 mas/yr
PM Declination
30.97 mas/yr
Galactic Cartesian (pc)
x = 0.495 · y = 0.324 · z = -0.806
Equatorial (J2000)
RA 33.17807° · Dec -53.74376°
Galactic ℓ, b
279.094° · -59.461°
Ecliptic λ, β
357.240° · -60.293°
HTM-20 index
-2093277181
Similar Worlds
Kepler-57 b
Sub-Neptune · K-type orange
Radius 3.14 R⊕ · 2,100.9 ly
TOI-1260 d
Sub-Neptune · K-type orange
Radius 3.12 R⊕ · 240.0 ly
Kepler-1536 b
Sub-Neptune · K-type orange
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Kepler-224 c
Sub-Neptune · K-type orange
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Kepler-1868 b
Sub-Neptune · K-type orange
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Kepler-324 c
Sub-Neptune · K-type orange
Radius 3.15 R⊕ · 1,635.9 ly