Key parameters at a glance

A radius of 3.23 Earth radii
A mass of 10.49 Earth masses
Surface gravity around 1.01 g
An orbital period of 4.363 days
Semi-major axis 0.0540 AU
Distance from Earth 103.60 light-years
Earth Similarity Index 0.614
Travel time at Voyager 1 speed 1,826,915 years

1 sibling around HD 12235

HD 12235 b 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 12235 b this	Sub-Neptune	3.23	10.49	4.363	—	2022
HD 12235 c	Gas Giant	12.50	3,135.70	36,336.707	—	2022

HD 12235 b Planet Profile

Physical Specs

Radius

3.23 R⊕

Radius (Jupiter)

0.288 R♃

Mass

10.49 M⊕

Mass (Jupiter)

0.033 M♃

Density

1.71 g/cm³

Surface Gravity

1.01 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.614

HZ Position Unknown

Controversial No

Discovery

Year 2022

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#325of 1978

top 16.4%

This planet

3.23R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1636 b 3.23 R⊕ HD 160691 d 3.23 R⊕ GJ 3138 d 3.23 R⊕

Metric	Earth	HD 12235 b	Jupiter
Radius (R⊕)	1.00	3.23	11.21
Mass (M⊕)	1.00	10.49	317.83
Density (g/cm³)	5.51	1.71	1.33
Surface Gravity (g)	1.00	1.01	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	10.488 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 12235

TIC

TIC 422679659

Gaia DR2

Gaia DR2 2511794495013074048

Gaia DR3

Gaia DR3 2511794495013074048

System

HD 12235

Percentile among Sub-Neptune cohort

Radius 3.230 R⊕ · percentile 83 / cohort 1978

Mass 10.488 M⊕ · percentile 76 / cohort 1978

Orbital period 4.36 d · percentile 10 / cohort 1946

Distance 31.76 pc · percentile 8 / cohort 1975

ESI 0.614 · percentile 84 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

4.363 days

Semi-major axis

0.0540 AU

Eccentricity

0.376

Inclination

— °

Year Length

A year here lasts approximately 4.36 Earth days (1.2% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0540 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.614

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Feng et al. 2022

Instrument

Multiple Instruments

Publication

2022-09

Observation locale

Ground

Discovery cohort

Planets confirmed in 2022 at Multiple Observatories (12 shown).

Kepler-138 e · Rocky Terrestrial HD 93351 b · Super-Earth GJ 1002 b · Rocky Terrestrial GJ 2030 b · Sub-Neptune GJ 3929 c · Sub-Neptune HD 217786 c · Sub-Neptune GJ 1002 c · Rocky Terrestrial HD 155918 b · Sub-Neptune HD 213519 b · Sub-Neptune HD 191939 g · Sub-Neptune GJ 514 b · Sub-Neptune HD 18143 b · Sub-Neptune

Host System: HD 12235

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,986 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.802 R☉

Stellar Mass

1.100 M☉

Metallicity [Fe/H]

0.31

Extended Stellar Properties

Surface gravity (log g)

3.968 dex

Stellar density

0.265 g/cm³

Metallicity ratio

[M/H]

Distance

31.76 parsec

Light-years 103.60 ly

V-band magnitude

5.88 mag

Voyager-speed travel 1,826,915 yr

Multi-band Host Photometry — 7 bands

Astrometric Data

Parallax

31.455 mas

Total Proper Motion

345.212 mas/yr

PM Right Ascension

230.91 mas/yr

PM Declination

-256.62 mas/yr

Galactic Cartesian (pc)

x = 0.864 · y = 0.500 · z = 0.054

Equatorial (J2000)

RA 30.03916° · Dec 3.09591°

Galactic ℓ, b

154.338° · -55.529°

Ecliptic λ, β

29.044° · -8.585°

HTM-20 index

1879477160