Key parameters at a glance

A radius of 2.52 Earth radii
A mass of 6.89 Earth masses
Surface gravity around 1.08 g
An orbital period of 13.671 days
Semi-major axis 0.0932 AU
Equilibrium temperature 470 K (196 °C)
Distance from Earth 49.69 light-years
Earth Similarity Index 0.523
Travel time at Voyager 1 speed 876,304 years
Almost certainly tidally locked to its host star given the close orbit

HD 238090 b Planet Profile

Physical Specs

Radius

2.52 R⊕

Radius (Jupiter)

0.225 R♃

Mass

6.89 M⊕

Mass (Jupiter)

0.022 M♃

Density

2.37 g/cm³

Surface Gravity

1.08 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.523

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#1147of 1978

top 57.9%

This planet

2.52R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-748 b 2.52 R⊕ Kepler-129 c 2.52 R⊕ TOI-1749 d 2.52 R⊕

Metric	Earth	HD 238090 b	Jupiter
Radius (R⊕)	1.00	2.52	11.21
Mass (M⊕)	1.00	6.89	317.83
Density (g/cm³)	5.51	2.37	1.33
Surface Gravity (g)	1.00	1.08	2.53
Insolation (S⊕)	1.00	8.10	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	6.890 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 238090

HIP

HIP 59514

TIC

TIC 224289449

Gaia DR2

Gaia DR2 1573086442800134272

Gaia DR3

Gaia DR3 1573086442800134272

System

HD 238090

Percentile among Sub-Neptune cohort

Radius 2.520 R⊕ · percentile 42 / cohort 1978

Mass 6.890 M⊕ · percentile 39 / cohort 1978

Orbital period 13.67 d · percentile 46 / cohort 1946

Distance 15.24 pc · percentile 3 / cohort 1975

ESI 0.523 · percentile 73 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.671 days

Semi-major axis

0.0932 AU

Eccentricity

0.300

Inclination

— °

Year Length

A year here lasts approximately 13.67 Earth days (3.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0932 AU.

Eq. Temperature

470K

(196 °C)

Insolation (S⊕)

8.10

Earth = 1.00

Earth Similarity (ESI)

0.523

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Stock et al. 2020

Instrument

Multiple Instruments

Publication

2020-11

Observation locale

Ground

Discovery cohort

Planets confirmed in 2020 at Multiple Observatories (12 shown).

GJ 3473 c · Sub-Neptune HIP 38594 b · Sub-Neptune HD 216520 c · Sub-Neptune HD 216520 b · Sub-Neptune HIP 107772 b · Sub-Neptune GJ 480 b · Sub-Neptune HIP 4845 b · Sub-Neptune HD 190007 b · Neptune-like GJ 687 c · Neptune-like GJ 2056 b · Neptune-like HIP 48714 b · Neptune-like HIP 38594 c · Neptune-like

Host System: HD 238090

Spectral Class

M-type red dwarf

Effective Temperature

3,933 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.570 R☉

Stellar Mass

0.578 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.700 dex

Stellar density

4.051 g/cm³

Systemic radial velocity

-17.67 km/s

Rotational v·sin i

2.00 km/s

Rotation period

96.70 days

Metallicity ratio

[Fe/H]

Distance

15.24 parsec

Light-years 49.69 ly

V-band magnitude

9.71 mag

Voyager-speed travel 876,304 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

65.608 mas

Total Proper Motion

249.960 mas/yr

PM Right Ascension

232.38 mas/yr

PM Declination

92.09 mas/yr

Galactic Cartesian (pc)

x = -0.580 · y = -0.031 · z = 0.814

Equatorial (J2000)

RA 183.08864° · Dec 54.48615°

Galactic ℓ, b

134.942° · 61.721°

Ecliptic λ, β

153.035° · 49.399°

HTM-20 index

-731090729