Key parameters at a glance

A radius of 3.19 Earth radii
A mass of 10.30 Earth masses
Surface gravity around 1.01 g
An orbital period of 35.730 days
Equilibrium temperature 640 K (367 °C)
Distance from Earth 176.04 light-years
Earth Similarity Index 0.359
Travel time at Voyager 1 speed 3,104,455 years

1 sibling around TOI-1774

HD 85426 c 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
TOI-1774.01	Sub-Neptune	2.78	8.50	16.710	824	2021
HD 85426 c this	Sub-Neptune	3.19	10.30	35.730	640	2026

HD 85426 c Planet Profile

Physical Specs

Radius

3.19 R⊕

Radius (Jupiter)

0.285 R♃

Mass

10.30 M⊕

Mass (Jupiter)

0.032 M♃

Density

1.74 g/cm³

Surface Gravity

1.01 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.359

HZ Position Unknown

Controversial No

Discovery

Year 2026

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#358of 1978

top 18.0%

This planet

3.19R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-188 c 3.19 R⊕ Kepler-1294 b 3.19 R⊕ Kepler-351 c 3.19 R⊕

Metric	Earth	HD 85426 c	Jupiter
Radius (R⊕)	1.00	3.19	11.21
Mass (M⊕)	1.00	10.30	317.83
Density (g/cm³)	5.51	1.74	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)	10.300 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 85426

HIP

HIP 48443

TIC

TIC 4897275

Gaia DR2

Gaia DR2 796063843195758208

Gaia DR3

Gaia DR3 796063843195758208

System

TOI-1774

Percentile among Sub-Neptune cohort

Radius 3.190 R⊕ · percentile 82 / cohort 1978

Mass 10.300 M⊕ · percentile 75 / cohort 1978

Orbital period 35.73 d · percentile 78 / cohort 1946

Distance 53.97 pc · percentile 12 / cohort 1975

ESI 0.359 · percentile 43 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

35.730 days

Semi-major axis

— AU

Eccentricity

0.060

Inclination

— °

Year Length

A year here lasts approximately 35.73 Earth days (9.8% of a terrestrial year) on a nearly circular orbit.

Extended Orbital Architecture

Semi-major axis / stellar radius

40.300

RV semi-amplitude (K)

2.000 m/s

Transit mid-time (BJD)

2,459,608.0000

Long. of periastron (ω)

143.00°

Eq. Temperature

640K

(367 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.359

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Lienhard et al. 2026

Instrument

Multiple Instruments

Publication

2026-01

Observation locale

Multiple Locales

Discovery cohort

Planets confirmed in 2026 at Multiple Observatories (12 shown).

DMPP-6 b · Sub-Neptune TOI-4336 A c · Super-Earth GJ 887 d · Sub-Neptune HD 176986 d · Sub-Neptune GJ 887 e · Rocky Terrestrial DMPP-6 c · Sub-Neptune DMPP-9 b · Sub-Neptune TOI-5789 d · Super-Earth TOI-5789 e · Sub-Neptune DMPP-2 c · Neptune-like DMPP-7 b · Neptune-like TOI-375 d · Gas Giant

Host System: TOI-1774

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,746 K — cooler than the Sun (5,778 K)

Estimated Age

7.40 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.130 R☉

Stellar Mass

0.991 M☉

Metallicity [Fe/H]

-0.02

Extended Stellar Properties

Surface gravity (log g)

4.330 dex

Stellar density

0.967 g/cm³

Rotational v·sin i

2.00 km/s

Rotation period

25.00 days

Activity index (log R'HK)

-4.920

Metallicity ratio

[Fe/H]

Distance

53.97 parsec

Light-years 176.04 ly

V-band magnitude

8.25 mag

Voyager-speed travel 3,104,455 yr

Multi-band Host Photometry — 7 bands

Astrometric Data

Parallax

18.499 mas

Total Proper Motion

304.356 mas/yr

PM Right Ascension

264.67 mas/yr

PM Declination

-150.27 mas/yr

Galactic Cartesian (pc)

x = -0.695 · y = 0.432 · z = 0.575

Equatorial (J2000)

RA 148.16193° · Dec 35.11101°

Galactic ℓ, b

189.721° · 51.241°

Ecliptic λ, β

138.043° · 20.858°

HTM-20 index

-1825106223