Key parameters at a glance

A radius of 5.39 Earth radii
A mass of 25.10 Earth masses
Surface gravity around 0.86 g
An orbital period of 49.748 days
Semi-major axis 0.2699 AU
Distance from Earth 127.07 light-years
Earth Similarity Index 0.455
Travel time at Voyager 1 speed 2,240,926 years

Context from the literature

HD 10180 is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six exoplanets have been observed orbiting it, and some studies have proposed up to nine potential planets, which would make it potentially the largest of all known planetary systems, including the Solar System.

Excerpted from Wikipedia · full article

5 siblings around HD 10180

HD 10180 e shares its host star with 5 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 10180 c	Unclassified	—	2,741.59	5.760	—	2010
HD 10180 d	Unclassified	—	3,295.88	16.357	—	2010
HD 10180 e this	Neptune-like	5.39	25.10	49.748	—	2010
HD 10180 f	Neptune-like	5.24	23.90	122.744	—	2010
HD 10180 g	Unclassified	—	3,375.34	604.670	—	2010
HD 10180 h	Neptune-like	9.40	64.40	2,205.000	—	2010

HD 10180 e Planet Profile

Physical Specs

Radius

5.39 R⊕

Radius (Jupiter)

0.481 R♃

Mass

25.10 M⊕

Mass (Jupiter)

0.079 M♃

Density

0.88 g/cm³

Surface Gravity

0.86 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.455

HZ Position Unknown

Controversial No

Discovery

Year 2010

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#330of 574

top 57.3%

This planet

5.39R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-1737 b 5.40 R⊕ HD 11964 c 5.38 R⊕ Kepler-677 b 5.38 R⊕

Metric	Earth	HD 10180 e	Jupiter
Radius (R⊕)	1.00	5.39	11.21
Mass (M⊕)	1.00	25.10	317.83
Density (g/cm³)	5.51	0.88	1.33
Surface Gravity (g)	1.00	0.86	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	25.585 M⊕	Lower bound from radial-velocity fitting.
Computed mass	25.100 M⊕	Model-computed mass (e.g. from mass-radius relation).

Star Catalogue Identifiers

HD 10180

HIP

HIP 7599

TIC

TIC 231836962

Gaia DR2

Gaia DR2 4716158250340258944

Gaia DR3

Gaia DR3 4716158250340258944

System

HD 10180

Percentile among Neptune-like cohort

Radius 5.390 R⊕ · percentile 43 / cohort 574

Mass 25.100 M⊕ · percentile 42 / cohort 574

Orbital period 49.75 d · percentile 70 / cohort 524

Distance 38.96 pc · percentile 12 / cohort 572

ESI 0.455 · percentile 82 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

49.748 days

Semi-major axis

0.2699 AU

Eccentricity

0.051

Inclination

90.00 °

Year Length

A year here lasts approximately 49.75 Earth days (13.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2699 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.455

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Lovis et al. 2011

Instrument

HARPS Spectrograph

Publication

2011-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2010 at La Silla Observatory (12 shown).

GJ 3634 b · Sub-Neptune HD 10180 f · Neptune-like GJ 676 A b · Gas Giant HD 204313 b · Gas Giant HD 28254 b · Gas Giant HD 1690 b · Gas Giant HD 10180 h · Neptune-like HD 113538 c · Gas Giant HD 25171 b · Gas Giant HD 8535 b · Gas Giant HD 44219 b · Gas Giant HD 43197 b · Gas Giant

Host System: HD 10180

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,911 K — hotter than the Sun (5,778 K)

Estimated Age

4.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.109 R☉

Stellar Mass

1.060 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

0.922 g/cm³

Systemic radial velocity

35.53 km/s

Rotational v·sin i

3.00 km/s

Activity index (log R'HK)

-5.040

Metallicity ratio

[Fe/H]

Distance

38.96 parsec

Light-years 127.07 ly

V-band magnitude

7.33 mag

Voyager-speed travel 2,240,926 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

25.638 mas

Total Proper Motion

16.588 mas/yr

PM Right Ascension

-14.38 mas/yr

PM Declination

8.27 mas/yr

Galactic Cartesian (pc)

x = 0.448 · y = 0.204 · z = -0.870

Equatorial (J2000)

RA 24.47311° · Dec -60.51149°

Galactic ℓ, b

292.805° · -55.694°

Ecliptic λ, β

340.440° · -61.611°

HTM-20 index

327679115

Wikipedia → Image: Wikimedia Commons · ESO and Digitized Sky Survey 2. Acknowledgment: Davide De Martin · CC BY 4.0