Key parameters at a glance

A radius of 2.80 Earth radii
A mass of 8.26 Earth masses
Surface gravity around 1.05 g
An orbital period of 5.749 days
Distance from Earth 109.13 light-years
Earth Similarity Index 0.664
Travel time at Voyager 1 speed 1,924,487 years

1 sibling around HD 23079

HD 23079 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
HD 23079 c this	Sub-Neptune	2.80	8.26	5.749	—	2025
HD 23079 b	Gas Giant	13.20	845.42	735.740	—	2001

HD 23079 c Planet Profile

Physical Specs

Radius

2.80 R⊕

Radius (Jupiter)

0.250 R♃

Mass

8.26 M⊕

Mass (Jupiter)

0.026 M♃

Density

2.07 g/cm³

Surface Gravity

1.05 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.664

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#742of 1978

top 37.5%

This planet

2.80R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-694 b 2.80 R⊕ Kepler-276 d 2.80 R⊕ Kepler-350 d 2.80 R⊕

Metric	Earth	HD 23079 c	Jupiter
Radius (R⊕)	1.00	2.80	11.21
Mass (M⊕)	1.00	8.26	317.83
Density (g/cm³)	5.51	2.07	1.33
Surface Gravity (g)	1.00	1.05	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	8.260 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 23079

HIP

HIP 17096

TIC

TIC 206402844

Gaia DR2

Gaia DR2 4733035238430992768

Gaia DR3

Gaia DR3 4733035238430992768

System

HD 23079

Percentile among Sub-Neptune cohort

Radius 2.800 R⊕ · percentile 62 / cohort 1978

Mass 8.260 M⊕ · percentile 57 / cohort 1978

Orbital period 5.75 d · percentile 16 / cohort 1946

Distance 33.46 pc · percentile 9 / cohort 1975

ESI 0.664 · percentile 89 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.749 days

Semi-major axis

— AU

Eccentricity

0.097

Inclination

— °

Year Length

A year here lasts approximately 5.75 Earth days (1.6% of a terrestrial year) on a nearly circular orbit.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.664

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Delisle et al. 2025

Instrument

HARPS Spectrograph

Publication

2025-09

Observation locale

Ground

Discovery cohort

Planets confirmed in 2025 at La Silla Observatory (12 shown).

Proxima Cen d · Rocky Terrestrial TOI-1203 c · Sub-Neptune HD 196067 c · Sub-Neptune HD 87816 b · Gas Giant HD 102888 b · Gas Giant HD 94890 c · Gas Giant TOI-756 c · Gas Giant TOI-1203 e · Neptune-like HD 94890 b · Gas Giant HD 87816 c · Gas Giant GJ 2126 b · Gas Giant HD 28471 d · Sub-Neptune

Host System: HD 23079

Spectral Class

F-type yellow-white

Effective Temperature

5,994 K — hotter than the Sun (5,778 K)

Estimated Age

2.60 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.080 R☉

Stellar Mass

1.160 M☉

Metallicity [Fe/H]

-0.13

Extended Stellar Properties

Surface gravity (log g)

4.370 dex

Stellar density

1.224 g/cm³

Systemic radial velocity

0.57 km/s

Rotational v·sin i

2.99 km/s

Rotation period

15.00 days

Activity index (log R'HK)

-4.929

Metallicity ratio

[Fe/H]

Distance

33.46 parsec

Light-years 109.13 ly

V-band magnitude

7.12 mag

Voyager-speed travel 1,924,487 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

29.858 mas

Total Proper Motion

213.739 mas/yr

PM Right Ascension

-192.88 mas/yr

PM Declination

-92.10 mas/yr

Galactic Cartesian (pc)

x = 0.346 · y = 0.494 · z = -0.798

Equatorial (J2000)

RA 54.92819° · Dec -52.91623°

Galactic ℓ, b

264.320° · -49.653°

Ecliptic λ, β

21.348° · -68.160°

HTM-20 index

2034377870

Observation Record

Photometric series

RV measurements

Archive notes