Key parameters at a glance

A radius of 2.23 Earth radii
A mass of 5.59 Earth masses
Surface gravity around 1.12 g
An orbital period of 13.505 days
Semi-major axis 0.1117 AU
Distance from Earth 76.49 light-years
Earth Similarity Index 0.745
Travel time at Voyager 1 speed 1,348,983 years

1 sibling around HD 1461

HD 1461 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 1461 b	Sub-Neptune	2.42	6.44	5.772	—	2010
HD 1461 c this	Sub-Neptune	2.23	5.59	13.505	—	2015

HD 1461 c Planet Profile

Physical Specs

Radius

2.23 R⊕

Radius (Jupiter)

0.199 R♃

Mass

5.59 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.77 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.745

HZ Position Unknown

Controversial No

Discovery

Year 2015

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#1622of 1978

top 82.0%

This planet

2.23R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-292 d 2.23 R⊕ Kepler-165 c 2.23 R⊕ Kepler-235 b 2.23 R⊕

Metric	Earth	HD 1461 c	Jupiter
Radius (R⊕)	1.00	2.23	11.21
Mass (M⊕)	1.00	5.59	317.83
Density (g/cm³)	5.51	2.77	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	5.590 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 1461

HIP

HIP 1499

TIC

TIC 37748347

Gaia DR2

Gaia DR2 2430102808294101760

Gaia DR3

Gaia DR3 2430102808294101760

System

HD 1461

Percentile among Sub-Neptune cohort

Radius 2.230 R⊕ · percentile 17 / cohort 1978

Mass 5.590 M⊕ · percentile 17 / cohort 1978

Orbital period 13.51 d · percentile 46 / cohort 1946

Distance 23.45 pc · percentile 5 / cohort 1975

ESI 0.745 · percentile 96 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.505 days

Semi-major axis

0.1117 AU

Eccentricity

0.305

Inclination

— °

Year Length

A year here lasts approximately 13.51 Earth days (3.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.1117 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

1.490 m/s

Transit mid-time (BJD)

2,455,200.1100

Long. of periastron (ω)

22.00°

Angular separation (arcsec)

4.76000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.745

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

D Iacute Az et al. 2016

Instrument

HARPS Spectrograph

Publication

2016-01

Observation locale

Ground

Discovery cohort

Planets confirmed in 2015 at La Silla Observatory (10 shown).

Wolf 1061 b · Rocky Terrestrial Wolf 1061 c · Super-Earth GJ 3341 b · Sub-Neptune Wolf 1061 d · Sub-Neptune HD 204313 c · Neptune-like GJ 3293 c · Neptune-like GJ 3293 b · Neptune-like WASP-41 c · Gas Giant HD 175607 b · Unclassified WASP-47 c · Unclassified

Host System: HD 1461

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,765 K — cooler than the Sun (5,778 K)

Estimated Age

7.12 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.152 R☉

Stellar Mass

1.020 M☉

Metallicity [Fe/H]

0.19

Extended Stellar Properties

Surface gravity (log g)

4.380 dex

Stellar density

1.009 g/cm³

Systemic radial velocity

-10.06 km/s

Rotational v·sin i

1.60 km/s

Activity index (log R'HK)

-5.030

Metallicity ratio

[Fe/H]

Distance

23.45 parsec

Light-years 76.49 ly

V-band magnitude

6.48 mag

Voyager-speed travel 1,348,983 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

42.609 mas

Total Proper Motion

441.915 mas/yr

PM Right Ascension

417.88 mas/yr

PM Declination

-143.77 mas/yr

Galactic Cartesian (pc)

x = 0.987 · y = 0.081 · z = -0.140

Equatorial (J2000)

RA 4.67626° · Dec -8.05362°

Galactic ℓ, b

99.307° · -69.410°

Ecliptic λ, β

1.060° · -9.245°

HTM-20 index

-1313543626

Observation Record

Photometric series

RV measurements

Stellar spectra