Key parameters at a glance
- A radius of 12.70 Earth radii
- A mass of 2,204.78 Earth masses
- Surface gravity around 13.67 g
- An orbital period of 3,128.410 days
- Semi-major axis 4.5500 AU
- Distance from Earth 209.13 light-years
- Earth Similarity Index 0.434
- Travel time at Voyager 1 speed 3,687,920 years
Context from the literature
HD 121056, or HIP 67851, is an aging giant star with a pair of orbiting exoplanets located in the southern constellation of Centaurus. This star is dimly visible to the naked eye with an apparent visual magnitude of 6.17. It is located at a distance of 209 light-years from the Sun, based on parallax measurements, and is drifting further away with a radial velocity of 5.6 km/s.
Excerpted from Wikipedia · full article
1 sibling around HIP 67851
HIP 67851 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 |
|---|---|---|---|---|---|---|
| HIP 67851 b | Gas Giant | 13.70 | 365.50 | 89.230 | — | 2015 |
| HIP 67851 c this | Gas Giant | 12.70 | 2,204.78 | 3,128.410 | — | 2015 |
HIP 67851 c Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1130of 1771
top 63.7%
This planet
12.70R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HIP 67851 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.70 | 11.21 |
| Mass (M⊕) | 1.00 | 2,204.78 | 317.83 |
| Density (g/cm³) | 5.51 | 5.91 | 1.33 |
| Surface Gravity (g) | 1.00 | 13.67 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 2,204.776 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 1,579.607 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 121056
HIP
HIP 67851
TIC
TIC 111947706
Gaia DR2
Gaia DR2 6169943210465504384
Gaia DR3
Gaia DR3 6169943210465504384
System
HIP 67851
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 8.57 Earth years on a highly eccentric trajectory at a mean orbital distance of 4.5500 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.434
0 = alien, 1 = Earth-identical
Discovery Paper
Primary reference
Jones et al. 2015Instrument
Multiple Instruments
Publication
2015-01
Observation locale
Ground
Discovery cohort
Planets confirmed in 2015 at Multiple Observatories (8 shown).
Host System: HIP 67851
Spectral Class
K-type orange
Effective Temperature
4,840 K — cooler than the Sun (5,778 K)
Estimated Age
5.46 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
5.450 R☉
Stellar Mass
1.280 M☉
Metallicity [Fe/H]
0.01
Extended Stellar Properties
Surface gravity (log g)
3.110 dex
Systemic radial velocity
5.58 km/s
Rotational v·sin i
3.33 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
15.567 mas
Total Proper Motion
303.039 mas/yr
PM Right Ascension
-295.04 mas/yr
PM Declination
-69.16 mas/yr
Galactic Cartesian (pc)
x = -0.717 · y = -0.389 · z = -0.578
Equatorial (J2000)
RA 208.46536° · Dec -35.31465°
Galactic ℓ, b
317.049° · 25.840°
Ecliptic λ, β
219.279° · -22.065°
HTM-20 index
-908909211
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