Key parameters at a glance
- A radius of 4.31 Earth radii
- A mass of 17.16 Earth masses
- Surface gravity around 0.92 g
- An orbital period of 34.959 days
- Semi-major axis 0.2110 AU
- Distance from Earth 155.88 light-years
- Earth Similarity Index 0.521
- Travel time at Voyager 1 speed 2,749,025 years
Context from the literature
HD 204313 is a star with two and possibly three exoplanetary companions in the southern constellation of Capricornus. With an apparent magnitude of 7.99, it is an eighth magnitude star that is too faint to be readily visible to the naked eye. The star is located at a distance of 157 light years from the Sun based on parallax measurements, but it is drifting closer with a radial velocity of −10 km/s.
Excerpted from Wikipedia · full article
2 siblings around HD 204313
HD 204313 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| HD 204313 c this | Neptune-like | 4.31 | 17.16 | 34.959 | — | 2015 |
| HD 204313 b | Gas Giant | 12.90 | 1,466.78 | 2,041.115 | — | 2010 |
| HD 204313 e | Gas Giant | 12.20 | 4,868.18 | 7,325.647 | — | 2022 |
HD 204313 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#491of 574
top 85.4%
This planet
4.31R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | HD 204313 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.31 | 11.21 |
| Mass (M⊕) | 1.00 | 17.16 | 317.83 |
| Density (g/cm³) | 5.51 | 1.18 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.92 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 17.163 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 204313
HIP
HIP 106006
TIC
TIC 99734092
Gaia DR2
Gaia DR2 6828450688663428224
Gaia DR3
Gaia DR3 6828450688663428224
System
HD 204313
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 34.96 Earth days (9.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2110 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.521
0 = alien, 1 = Earth-identical
Discovery Paper
Primary reference
D Iacute Az et al. 2016Instrument
Multiple Instruments
Publication
2016-01
Observation locale
Ground
Discovery cohort
Planets confirmed in 2015 at La Silla Observatory (10 shown).
Host System: HD 204313
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,767 K — cooler than the Sun (5,778 K)
Estimated Age
3.38 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.100 R☉
Stellar Mass
1.030 M☉
Metallicity [Fe/H]
0.18
Extended Stellar Properties
Surface gravity (log g)
4.370 dex
Stellar density
1.015 g/cm³
Systemic radial velocity
-9.74 km/s
Rotational v·sin i
2.40 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
20.894 mas
Total Proper Motion
273.881 mas/yr
PM Right Ascension
42.76 mas/yr
PM Declination
-270.52 mas/yr
Galactic Cartesian (pc)
x = 0.733 · y = -0.571 · z = -0.370
Equatorial (J2000)
RA 322.05106° · Dec -21.72742°
Galactic ℓ, b
28.026° · -43.729°
Ecliptic λ, β
317.490° · -6.454°
HTM-20 index
-522785699
Observation Record
Photometric series
1
RV measurements
1
Archive notes
1
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