Key parameters at a glance
- A radius of 2.46 Earth radii
- A mass of 6.60 Earth masses
- Surface gravity around 1.09 g
- An orbital period of 18.560 days
- Semi-major axis 0.1340 AU
- Distance from Earth 59.59 light-years
- Earth Similarity Index 0.710
- Travel time at Voyager 1 speed 1,050,801 years
- Almost certainly tidally locked to its host star given the close orbit
HD 154088 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1245of 1978
top 62.9%
This planet
2.46R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | HD 154088 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.46 | 11.21 |
| Mass (M⊕) | 1.00 | 6.60 | 317.83 |
| Density (g/cm³) | 5.51 | 2.44 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.09 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 6.600 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
HD
HD 154088
HIP
HIP 83541
TIC
TIC 20856917
Gaia DR2
Gaia DR2 6029992663310612096
Gaia DR3
Gaia DR3 6029992663310612096
System
HD 154088
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 18.56 Earth days (5.1% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.1340 AU.
Eq. Temperature
—
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.710
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 154088
Spectral Class
K-type orange
Effective Temperature
5,374 K — cooler than the Sun (5,778 K)
Estimated Age
8.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.950 R☉
Stellar Mass
0.910 M☉
Metallicity [Fe/H]
0.28
Extended Stellar Properties
Surface gravity (log g)
4.370 dex
Stellar density
1.411 g/cm³
Systemic radial velocity
14.90 km/s
Rotational v·sin i
1.90 km/s
Activity index (log R'HK)
-5.050
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 8 bands
Astrometric Data
Parallax
54.708 mas
Total Proper Motion
281.200 mas/yr
PM Right Ascension
83.23 mas/yr
PM Declination
-268.60 mas/yr
Galactic Cartesian (pc)
x = -0.211 · y = -0.852 · z = -0.478
Equatorial (J2000)
RA 256.11642° · Dec -28.58383°
Galactic ℓ, b
355.237° · 7.673°
Ecliptic λ, β
257.770° · -5.732°
HTM-20 index
1233446724
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