Key parameters at a glance
- A radius of 12.80 Earth radii
- A mass of 1,906.97 Earth masses
- Surface gravity around 11.64 g
- An orbital period of 9,090.000 days
- Semi-major axis 8.5000 AU
- Distance from Earth 128.44 light-years
- Earth Similarity Index 0.438
- Travel time at Voyager 1 speed 2,265,095 years
Context from the literature
HD 28185 is a single yellow dwarf star similar to the Sun, located 128 light-years away from Earth in the constellation Eridanus. The designation HD 28185 refers to its entry in the Henry Draper catalogue. The star is known to possess two long-period extrasolar planets.
Excerpted from Wikipedia · full article
1 sibling around HD 28185
HD 28185 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 28185 b | Gas Giant | 12.80 | 1,859.30 | 385.920 | — | 2001 |
| HD 28185 c this | Gas Giant | 12.80 | 1,906.97 | 9,090.000 | — | 2022 |
HD 28185 c Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1063of 1771
top 60.0%
This planet
12.80R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | HD 28185 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.80 | 11.21 |
| Mass (M⊕) | 1.00 | 1,906.97 | 317.83 |
| Density (g/cm³) | 5.51 | 5.00 | 1.33 |
| Surface Gravity (g) | 1.00 | 11.64 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 1,906.970 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 1,716.273 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 28185
HIP
HIP 20723
TIC
TIC 37947783
Gaia DR2
Gaia DR2 3179384931394690304
Gaia DR3
Gaia DR3 3179384931394690304
System
HD 28185
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts about 24.89 Earth years on a mildly elliptical path at a mean orbital distance of 8.5000 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.438
0 = alien, 1 = Earth-identical
Detection Signatures
Radial velocity
Stellar wobble has been measured spectroscopically.
Astrometry
Positional wobble of the host star was measured.
Discovery Paper
Primary reference
Feng et al. 2022Instrument
Multiple Instruments
Publication
2022-09
Observation locale
Ground
Discovery cohort
Planets confirmed in 2022 at Multiple Observatories (12 shown).
Host System: HD 28185
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,602 K — cooler than the Sun (5,778 K)
Estimated Age
8.30 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.048 R☉
Stellar Mass
0.974 M☉
Metallicity [Fe/H]
0.19
Extended Stellar Properties
Surface gravity (log g)
4.386 dex
Stellar density
1.117 g/cm³
Systemic radial velocity
50.25 km/s
Rotational v·sin i
2.54 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
25.364 mas
Total Proper Motion
103.141 mas/yr
PM Right Ascension
84.07 mas/yr
PM Declination
-59.75 mas/yr
Galactic Cartesian (pc)
x = 0.390 · y = 0.902 · z = -0.183
Equatorial (J2000)
RA 66.61005° · Dec -10.55108°
Galactic ℓ, b
205.594° · -36.931°
Ecliptic λ, β
62.661° · -31.797°
HTM-20 index
1040425167
Observation Record
Photometric series
1
RV measurements
3
Archive notes
2
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