Key parameters at a glance

A radius of 9.35 Earth radii
A mass of 63.88 Earth masses
Surface gravity around 0.73 g
An orbital period of 515.400 days
Semi-major axis 1.3000 AU
Distance from Earth 152.06 light-years
Earth Similarity Index 0.320
Travel time at Voyager 1 speed 2,681,609 years

1 sibling around HD 24040

HD 24040 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 24040 c this	Neptune-like	9.35	63.88	515.400	—	2021
HD 24040 b	Gas Giant	12.90	1,589.14	3,668.000	—	2006

HD 24040 c Planet Profile

Physical Specs

Radius

9.35 R⊕

Radius (Jupiter)

0.834 R♃

Mass

63.88 M⊕

Mass (Jupiter)

0.201 M♃

Density

0.43 g/cm³

Surface Gravity

0.73 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.320

HZ Position Unknown

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#53of 574

top 9.1%

This planet

9.35R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

PH2 b 9.34 R⊕ HD 33142 d 9.32 R⊕ HD 137388 b 9.32 R⊕

Metric	Earth	HD 24040 c	Jupiter
Radius (R⊕)	1.00	9.35	11.21
Mass (M⊕)	1.00	63.88	317.83
Density (g/cm³)	5.51	0.43	1.33
Surface Gravity (g)	1.00	0.73	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	63.884 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 24040

HIP

HIP 17960

TIC

TIC 456863621

Gaia DR2

Gaia DR2 43802039287826432

Gaia DR3

Gaia DR3 43802039287826432

System

HD 24040

Percentile among Neptune-like cohort

Radius 9.350 R⊕ · percentile 91 / cohort 574

Mass 63.884 M⊕ · percentile 82 / cohort 574

Orbital period 515.40 d · percentile 95 / cohort 524

Distance 46.62 pc · percentile 15 / cohort 572

ESI 0.320 · percentile 55 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

515.400 days

Semi-major axis

1.3000 AU

Eccentricity

0.110

Inclination

— °

Year Length

A year here lasts about 1.41 Earth years on a mildly elliptical path at a mean orbital distance of 1.3000 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

4.850 m/s

Transit mid-time (BJD)

2,454,984.0000

Long. of periastron (ω)

-17.19°

Angular separation (arcsec)

27.90000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.320

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Rosenthal et al. 2021

Instrument

Multiple Instruments

Publication

2021-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at Multiple Observatories (12 shown).

L 98-59 e · Super-Earth GJ 393 b · Rocky Terrestrial HD 168009 b · Sub-Neptune HD 164922 e · Sub-Neptune HD 95735 c · Sub-Neptune HD 141004 b · Sub-Neptune HD 107148 c · Neptune-like TOI-178 f · Sub-Neptune TYC 0434-04538-1 b · Gas Giant HIP 56640 b · Gas Giant HD 137496 c · Gas Giant HD 156668 c · Neptune-like

Host System: HD 24040

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,776 K — cooler than the Sun (5,778 K)

Estimated Age

6.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.387 R☉

Stellar Mass

1.104 M☉

Metallicity [Fe/H]

0.20

Extended Stellar Properties

Surface gravity (log g)

4.198 dex

Stellar density

0.554 g/cm³

Systemic radial velocity

-9.90 km/s

Rotational v·sin i

2.39 km/s

Activity index (log R'HK)

-5.090

Metallicity ratio

[Fe/H]

Distance

46.62 parsec

Light-years 152.06 ly

V-band magnitude

7.52 mag

Voyager-speed travel 2,681,609 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

21.420 mas

Total Proper Motion

275.382 mas/yr

PM Right Ascension

113.22 mas/yr

PM Declination

-251.03 mas/yr

Galactic Cartesian (pc)

x = 0.511 · y = 0.805 · z = 0.300

Equatorial (J2000)

RA 57.59621° · Dec 17.47529°

Galactic ℓ, b

172.293° · -27.781°

Ecliptic λ, β

59.221° · -2.569°

HTM-20 index

1225849445