Key parameters at a glance

A radius of 2.42 Earth radii
A mass of 6.44 Earth masses
Surface gravity around 1.10 g
An orbital period of 5.772 days
Semi-major axis 0.0634 AU
Distance from Earth 76.49 light-years
Earth Similarity Index 0.716
Travel time at Voyager 1 speed 1,348,983 years

Context from the literature

HD 1461 b is an extrasolar planet, orbiting the 6th magnitude G-type star HD 1461, 76.5 light years away in the constellation Cetus. This planet has a minimum mass 6.4 times that of Earth and orbits at a distance of 0.0634 AU with an eccentricity of less than 0.131. It is currently unknown whether the planet is a gas giant like Uranus or Neptune, or has terrestrial composition like CoRoT-7b. This planet was announced on 13 December 2009 after it was discovered using radial velocity measurements taken at the Keck and Anglo-Australian Observatories.

Excerpted from Wikipedia · full article

1 sibling around HD 1461

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

HD 1461 b Planet Profile

Physical Specs

Radius

2.42 R⊕

Radius (Jupiter)

0.216 R♃

Mass

6.44 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.50 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.716

HZ Position Unknown

Controversial No

Discovery

Year 2010

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#1299of 1978

top 65.6%

This planet

2.42R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-43 c 2.42 R⊕ Kepler-920 b 2.42 R⊕ Kepler-717 b 2.42 R⊕

Metric	Earth	HD 1461 b	Jupiter
Radius (R⊕)	1.00	2.42	11.21
Mass (M⊕)	1.00	6.44	317.83
Density (g/cm³)	5.51	2.50	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	6.440 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 2.420 R⊕ · percentile 34 / cohort 1978

Mass 6.440 M⊕ · percentile 32 / cohort 1978

Orbital period 5.77 d · percentile 16 / cohort 1946

Distance 23.45 pc · percentile 5 / cohort 1975

ESI 0.716 · percentile 94 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.772 days

Semi-major axis

0.0634 AU

Eccentricity

0.172

Inclination

— °

Year Length

A year here lasts approximately 5.77 Earth days (1.6% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0634 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

2.280 m/s

Transit mid-time (BJD)

2,455,839.3700

Long. of periastron (ω)

-10.00°

Angular separation (arcsec)

2.70000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.716

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Rivera et al. 2010

Instrument

HIRES Spectrometer

Publication

2010-01

Observation locale

Ground

Discovery cohort

Planets confirmed in 2010 at W. M. Keck Observatory (12 shown).

HD 156668 b · Super-Earth GJ 876 e · Sub-Neptune HAT-P-17 c · Gas Giant HD 97658 b · Sub-Neptune HD 163607 c · Gas Giant HD 177830 c · Neptune-like HD 218566 b · Neptune-like HD 102956 b · Gas Giant HD 163607 b · Gas Giant GJ 1148 b · Gas Giant HD 31253 b · Gas Giant HD 164509 b · Gas Giant

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

Archive notes

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