Key parameters at a glance

A radius of 13.70 Earth radii
A mass of 390.93 Earth masses
Surface gravity around 2.08 g
An orbital period of 383.000 days
Semi-major axis 1.0600 AU
Distance from Earth 161.56 light-years
Earth Similarity Index 0.325
Travel time at Voyager 1 speed 2,849,054 years

HD 100777 b Planet Profile

Physical Specs

Radius

13.70 R⊕

Radius (Jupiter)

1.220 R♃

Mass

390.93 M⊕

Mass (Jupiter)

1.230 M♃

Density

0.84 g/cm³

Surface Gravity

2.08 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.325

HZ Position Unknown

Controversial No

Discovery

Year 2007

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#554of 1771

top 31.2%

This planet

13.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 148164 b 13.70 R⊕ HD 114783 b 13.70 R⊕ HD 159243 b 13.70 R⊕

Metric	Earth	HD 100777 b	Jupiter
Radius (R⊕)	1.00	13.70	11.21
Mass (M⊕)	1.00	390.93	317.83
Density (g/cm³)	5.51	0.84	1.33
Surface Gravity (g)	1.00	2.08	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	390.929 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	368.670 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 100777

HIP

HIP 56572

TIC

TIC 49427341

Gaia DR2

Gaia DR2 3786035184916139136

Gaia DR3

Gaia DR3 3786035184916139136

System

HD 100777

Percentile among Gas Giant cohort

Radius 13.700 R⊕ · percentile 66 / cohort 1771

Mass 390.929 M⊕ · percentile 41 / cohort 1747

Orbital period 383.00 d · percentile 63 / cohort 1533

Distance 49.53 pc · percentile 19 / cohort 1759

ESI 0.325 · percentile 64 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

383.000 days

Semi-major axis

1.0600 AU

Eccentricity

0.380

Inclination

90.00 °

Year Length

A year here lasts about 1.05 Earth years on a highly eccentric trajectory at a mean orbital distance of 1.0600 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.325

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Naef et al. 2007

Instrument

HARPS Spectrograph

Publication

2007-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2007 at La Silla Observatory (10 shown).

GJ 581 c · Sub-Neptune GJ 674 b · Sub-Neptune HD 219828 b · Neptune-like HD 70573 b · Gas Giant HD 221287 b · Gas Giant HD 171028 b · Gas Giant BD-13 2130 b · Gas Giant HD 156846 b · Gas Giant HD 190647 b · Gas Giant HD 4113 b · Gas Giant

Host System: HD 100777

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,533 K — cooler than the Sun (5,778 K)

Estimated Age

5.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.040 R☉

Stellar Mass

1.080 M☉

Metallicity [Fe/H]

-0.27

Extended Stellar Properties

Surface gravity (log g)

4.320 dex

Stellar density

1.159 g/cm³

Systemic radial velocity

1.25 km/s

Rotational v·sin i

1.80 km/s

Activity index (log R'HK)

-5.090

Metallicity ratio

[Fe/H]

Distance

49.53 parsec

Light-years 161.56 ly

V-band magnitude

8.42 mag

Voyager-speed travel 2,849,054 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

20.160 mas

Total Proper Motion

37.136 mas/yr

PM Right Ascension

-11.35 mas/yr

PM Declination

35.36 mas/yr

Galactic Cartesian (pc)

x = -0.991 · y = 0.105 · z = -0.083

Equatorial (J2000)

RA 173.96463° · Dec -4.75554°

Galactic ℓ, b

270.285° · 53.257°

Ecliptic λ, β

176.350° · -6.762°

HTM-20 index

1331747105

Observation Record

Photometric series

RV measurements

Archive notes