Key parameters at a glance

A radius of 12.70 Earth radii
A mass of 2,080.00 Earth masses
Surface gravity around 12.90 g
An orbital period of 711.000 days
Semi-major axis 1.9300 AU
Distance from Earth 221.57 light-years
Earth Similarity Index 0.441
Travel time at Voyager 1 speed 3,907,349 years

Context from the literature

Eta2 Hydri b, commonly known as HD 11977 b, is an extrasolar planet that is approximately 217 light-years away in the constellation of Hydrus. The presence of the planet around an intermediately massive giant star provides indirect evidence for the existence of planetary systems around A-type stars.

Excerpted from Wikipedia · full article

HD 11977 b Planet Profile

Physical Specs

Radius

12.70 R⊕

Radius (Jupiter)

1.130 R♃

Mass

2,080.00 M⊕

Mass (Jupiter)

6.540 M♃

Density

5.58 g/cm³

Surface Gravity

12.90 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.441

HZ Position Unknown

Controversial No

Discovery

Year 2005

Method Radial Velocity

Facility La Silla Observatory

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#1130of 1771

top 63.7%

This planet

12.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 168863 b 12.70 R⊕ HD 233604 b 12.70 R⊕ Kepler-424 c 12.70 R⊕

Metric	Earth	HD 11977 b	Jupiter
Radius (R⊕)	1.00	12.70	11.21
Mass (M⊕)	1.00	2,080.00	317.83
Density (g/cm³)	5.51	5.58	1.33
Surface Gravity (g)	1.00	12.90	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	2,080.000 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 11977

HIP

HIP 8928

TIC

TIC 232074535

Gaia DR2

Gaia DR2 4697508196671120000

Gaia DR3

Gaia DR3 4697508196671120000

System

HD 11977

Percentile among Gas Giant cohort

Radius 12.700 R⊕ · percentile 34 / cohort 1771

Mass 2,080.000 M⊕ · percentile 81 / cohort 1747

Orbital period 711.00 d · percentile 73 / cohort 1533

Distance 67.93 pc · percentile 28 / cohort 1759

ESI 0.441 · percentile 98 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

711.000 days

Semi-major axis

1.9300 AU

Eccentricity

0.400

Inclination

— °

Year Length

A year here lasts about 1.95 Earth years on a highly eccentric trajectory at a mean orbital distance of 1.9300 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.441

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Setiawan et al. 2005

Instrument

FEROS Spectrograph

Publication

2005-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 2005 at La Silla Observatory (10 shown).

HD 4308 b · Neptune-like GJ 581 b · Neptune-like HD 142022 A b · Gas Giant HD 102117 b · Neptune-like HD 101930 b · Gas Giant HD 27894 b · Gas Giant HD 212301 b · Gas Giant HD 93083 b · Gas Giant HD 63454 b · Gas Giant HD 2638 b · Gas Giant

Host System: HD 11977

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

4,970 K — cooler than the Sun (5,778 K)

Estimated Age

1.20 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

10.090 R☉

Stellar Mass

1.910 M☉

Metallicity [Fe/H]

-0.21

Extended Stellar Properties

Surface gravity (log g)

2.900 dex

Systemic radial velocity

-18.01 km/s

Rotational v·sin i

2.40 km/s

Metallicity ratio

[Fe/H]

Distance

67.93 parsec

Light-years 221.57 ly

V-band magnitude

4.68 mag

Voyager-speed travel 3,907,349 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

14.694 mas

Total Proper Motion

105.574 mas/yr

PM Right Ascension

75.68 mas/yr

PM Declination

73.61 mas/yr

Galactic Cartesian (pc)

x = 0.333 · y = 0.183 · z = -0.925

Equatorial (J2000)

RA 28.73474° · Dec -67.64699°

Galactic ℓ, b

293.925° · -48.356°

Ecliptic λ, β

329.026° · -67.112°

HTM-20 index

-1217980984

Wikipedia →