Key parameters at a glance
- A radius of 8.24 Earth radii
- A mass of 51.49 Earth masses
- Surface gravity around 0.76 g
- An orbital period of 36.070 days
- Semi-major axis 0.1980 AU
- Distance from Earth 142.93 light-years
- Earth Similarity Index 0.347
- Travel time at Voyager 1 speed 2,520,502 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around HD 27894
HD 27894 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 27894 b | Gas Giant | 14.10 | 196.74 | 18.019 | — | 2005 |
| HD 27894 c this | Neptune-like | 8.24 | 51.49 | 36.070 | — | 2017 |
| HD 27894 d | Gas Giant | 12.70 | 2,063.66 | 5,019.542 | — | 2017 |
HD 27894 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#140of 574
top 24.2%
This planet
8.24R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | HD 27894 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 8.24 | 11.21 |
| Mass (M⊕) | 1.00 | 51.49 | 317.83 |
| Density (g/cm³) | 5.51 | 0.51 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.76 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 51.488 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 27894
HIP
HIP 20277
TIC
TIC 396697266
Gaia DR2
Gaia DR2 4678605152248591488
Gaia DR3
Gaia DR3 4678605152248591488
System
HD 27894
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 36.07 Earth days (9.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1980 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.347
0 = alien, 1 = Earth-identical
Insufficient insolation data. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Trifonov et al. 2017Instrument
HARPS Spectrograph
Publication
2017-06
Observation locale
Ground
Discovery cohort
Planets confirmed in 2017 at La Silla Observatory (12 shown).
Host System: HD 27894
Spectral Class
K-type orange
Effective Temperature
4,875 K — cooler than the Sun (5,778 K)
Estimated Age
3.90 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.892 R☉
Stellar Mass
0.800 M☉
Metallicity [Fe/H]
0.30
Extended Stellar Properties
Surface gravity (log g)
4.220 dex
Stellar density
1.846 g/cm³
Systemic radial velocity
82.90 km/s
Rotational v·sin i
1.50 km/s
Rotation period
44.00 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
22.791 mas
Total Proper Motion
325.715 mas/yr
PM Right Ascension
182.31 mas/yr
PM Declination
269.91 mas/yr
Galactic Cartesian (pc)
x = 0.213 · y = 0.462 · z = -0.861
Equatorial (J2000)
RA 65.19757° · Dec -59.40968°
Galactic ℓ, b
270.100° · -42.009°
Ecliptic λ, β
20.873° · -76.793°
HTM-20 index
1725638851
Observation Record
Photometric series
1
RV measurements
1
Archive notes
1
Similar Worlds
K2-281 b
Neptune-like · K-type orange
Radius 8.18 R⊕ · 1,494.2 ly
K2-127 b
Neptune-like · K-type orange
Radius 8.37 R⊕ · 2,315.7 ly
BD-06 1339 c
Neptune-like · K-type orange
Radius 8.38 R⊕ · 66.1 ly
HATS-72 b
Neptune-like · K-type orange
Radius 8.10 R⊕ · 416.1 ly
GJ 414 A c
Neptune-like · K-type orange
Radius 8.40 R⊕ · 38.8 ly
Kepler-16 b
Neptune-like · K-type orange
Radius 8.45 R⊕ · 244.9 ly