Key parameters at a glance

A radius of 3.46 Earth radii
A mass of 11.80 Earth masses
Surface gravity around 0.99 g
An orbital period of 31.560 days
Semi-major axis 0.1860 AU
Distance from Earth 40.96 light-years
Earth Similarity Index 0.592
Travel time at Voyager 1 speed 722,369 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

HD 69830 c is an exoplanet orbiting HD 69830. It is the second-closest planet in its system and has a minimum mass 12 times that of Earth. Based on theoretical modeling in the 2006 discovery paper, it is likely to be a rocky planet, not a gas giant. However, other work has found that if it had formed as a gas giant, it would have stayed that way, and it is now understood that planets this massive are rarely rocky.

Excerpted from Wikipedia · full article

2 siblings around HD 69830

HD 69830 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 69830 b	Sub-Neptune	3.17	10.20	8.667	—	2006
HD 69830 c this	Sub-Neptune	3.46	11.80	31.560	—	2006
HD 69830 d	Neptune-like	4.45	18.10	197.000	—	2006

HD 69830 c Planet Profile

Physical Specs

Radius

3.46 R⊕

Radius (Jupiter)

0.309 R♃

Mass

11.80 M⊕

Mass (Jupiter)

0.037 M♃

Density

1.57 g/cm³

Surface Gravity

0.99 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.592

HZ Position Unknown

Controversial No

Discovery

Year 2006

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#193of 1978

top 9.7%

This planet

3.46R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 24085 b 3.46 R⊕ Kepler-1533 b 3.46 R⊕ TOI-1853 b 3.46 R⊕

Metric	Earth	HD 69830 c	Jupiter
Radius (R⊕)	1.00	3.46	11.21
Mass (M⊕)	1.00	11.80	317.83
Density (g/cm³)	5.51	1.57	1.33
Surface Gravity (g)	1.00	0.99	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	11.800 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 69830

HIP

HIP 40693

TIC

TIC 307624961

Gaia DR2

Gaia DR2 5726982995343100928

Gaia DR3

Gaia DR3 5726982995343100928

System

HD 69830

Percentile among Sub-Neptune cohort

Radius 3.460 R⊕ · percentile 90 / cohort 1978

Mass 11.800 M⊕ · percentile 83 / cohort 1978

Orbital period 31.56 d · percentile 75 / cohort 1946

Distance 12.56 pc · percentile 2 / cohort 1975

ESI 0.592 · percentile 81 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

31.560 days

Semi-major axis

0.1860 AU

Eccentricity

0.130

Inclination

— °

Year Length

A year here lasts approximately 31.56 Earth days (8.6% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1860 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

2.660 m/s

Transit mid-time (BJD)

2,455,197.2800

Long. of periastron (ω)

221.00°

Angular separation (arcsec)

14.80000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.592

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Lovis et al. 2006

Instrument

HARPS Spectrograph

Publication

2006-05

Observation locale

Ground

Discovery cohort

Planets confirmed in 2006 at La Silla Observatory (3 shown).

HD 69830 b · Sub-Neptune HD 69830 d · Neptune-like HD 160691 e · Unclassified

Host System: HD 69830

Spectral Class

K-type orange

Effective Temperature

5,385 K — cooler than the Sun (5,778 K)

Estimated Age

7.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.887 R☉

Stellar Mass

0.860 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

1.830 g/cm³

Systemic radial velocity

29.80 km/s

Rotational v·sin i

1.10 km/s

Activity index (log R'HK)

-4.950

Metallicity ratio

[Fe/H]

Distance

12.56 parsec

Light-years 40.96 ly

V-band magnitude

5.96 mag

Voyager-speed travel 722,369 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

79.595 mas

Total Proper Motion

1,026.855 mas/yr

PM Right Ascension

278.79 mas/yr

PM Declination

-988.29 mas/yr

Galactic Cartesian (pc)

x = -0.554 · y = 0.803 · z = -0.219

Equatorial (J2000)

RA 124.60101° · Dec -12.63642°

Galactic ℓ, b

234.568° · 12.823°

Ecliptic λ, β

130.447° · -31.346°

HTM-20 index

1003371150

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes

Wikipedia → Image: Wikimedia Commons · T. Pyle (SSC) · Public domain

Similar Worlds

TOI-1853 b

Sub-Neptune · K-type orange

Radius 3.46 R⊕ · 538.5 ly

TOI-1246 d

Sub-Neptune · K-type orange

Radius 3.43 R⊕ · 552.6 ly

TOI-5076 b

Sub-Neptune · K-type orange

Radius 3.49 R⊕ · 270.2 ly

Kepler-357 d

Sub-Neptune · K-type orange

Radius 3.43 R⊕ · 2,245.8 ly

TOI-5789 e

Sub-Neptune · K-type orange

Radius 3.43 R⊕ · 66.7 ly

Kepler-712 b

Sub-Neptune · K-type orange

Radius 3.41 R⊕ · 2,845.7 ly

Explore Related Categories

Sub-Neptune Planets Radial Velocity Discoveries La Silla Observatory Mission K-type orange Hosts