Key parameters at a glance
- A radius of 1.99 Earth radii
- A mass of 4.62 Earth masses
- Surface gravity around 1.17 g
- An orbital period of 5.637 days
- Semi-major axis 0.0590 AU
- Distance from Earth 86.15 light-years
- Earth Similarity Index 0.787
- Travel time at Voyager 1 speed 1,519,218 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around HD 39194
HD 39194 b 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 39194 b this | Super-Earth | 1.99 | 4.62 | 5.637 | — | 2021 |
| HD 39194 c | Sub-Neptune | 2.65 | 7.49 | 14.031 | — | 2021 |
| HD 39194 d | Sub-Neptune | 2.12 | 5.16 | 33.874 | — | 2021 |
HD 39194 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#4of 1176
top 0.3%
This planet
1.99R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | HD 39194 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.99 | 11.21 |
| Mass (M⊕) | 1.00 | 4.62 | 317.83 |
| Density (g/cm³) | 5.51 | 3.22 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.17 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 4.620 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 39194
HIP
HIP 27080
TIC
TIC 389506883
Gaia DR2
Gaia DR2 4657193606465368704
Gaia DR3
Gaia DR3 4657193606465368704
System
HD 39194
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.64 Earth days (1.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0590 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.787
0 = alien, 1 = Earth-identical
Insufficient insolation data. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Unger et al. 2021Instrument
HARPS Spectrograph
Publication
2021-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2021 at La Silla Observatory (12 shown).
Host System: HD 39194
Spectral Class
K-type orange
Effective Temperature
5,205 K — cooler than the Sun (5,778 K)
Estimated Age
10.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.784 R☉
Stellar Mass
0.860 M☉
Metallicity [Fe/H]
-0.61
Extended Stellar Properties
Surface gravity (log g)
4.530 dex
Stellar density
2.577 g/cm³
Systemic radial velocity
7.69 km/s
Rotational v·sin i
2.00 km/s
Activity index (log R'HK)
-4.950
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 8 bands
Astrometric Data
Parallax
37.831 mas
Total Proper Motion
1,276.840 mas/yr
PM Right Ascension
-309.42 mas/yr
PM Declination
1,238.78 mas/yr
Galactic Cartesian (pc)
x = 0.023 · y = 0.339 · z = -0.941
Equatorial (J2000)
RA 86.12907° · Dec -70.13824°
Galactic ℓ, b
280.609° · -31.058°
Ecliptic λ, β
289.969° · -86.150°
HTM-20 index
675223832
Similar Worlds
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Super-Earth · K-type orange
Radius 1.99 R⊕ · 366.8 ly
TOI-2194 b
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HD 235088 b
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GJ 9827 d
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K2-126 b
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Radius 1.97 R⊕ · 2,550.8 ly