Key parameters at a glance

A radius of 13.60 Earth radii
A mass of 410.00 Earth masses
Surface gravity around 2.22 g
An orbital period of 442.190 days
Semi-major axis 1.1300 AU
Distance from Earth 69.47 light-years
Earth Similarity Index 0.331
Travel time at Voyager 1 speed 1,225,039 years

HD 210277 b Planet Profile

Physical Specs

Radius

13.60 R⊕

Radius (Jupiter)

1.220 R♃

Mass

410.00 M⊕

Mass (Jupiter)

1.290 M♃

Density

0.90 g/cm³

Surface Gravity

2.22 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.331

HZ Position Unknown

Controversial No

Discovery

Year 1998

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#609of 1771

top 34.3%

This planet

13.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 19994 b 13.60 R⊕ HD 205739 b 13.60 R⊕ HD 79498 b 13.60 R⊕

Metric	Earth	HD 210277 b	Jupiter
Radius (R⊕)	1.00	13.60	11.21
Mass (M⊕)	1.00	410.00	317.83
Density (g/cm³)	5.51	0.90	1.33
Surface Gravity (g)	1.00	2.22	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	410.001 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 210277

HIP

HIP 109378

TIC

TIC 50227884

Gaia DR2

Gaia DR2 2619706544757416192

Gaia DR3

Gaia DR3 2619706544757416192

System

HD 210277

Percentile among Gas Giant cohort

Radius 13.600 R⊕ · percentile 63 / cohort 1771

Mass 410.001 M⊕ · percentile 43 / cohort 1747

Orbital period 442.19 d · percentile 66 / cohort 1533

Distance 21.30 pc · percentile 5 / cohort 1759

ESI 0.331 · percentile 65 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

442.190 days

Semi-major axis

1.1300 AU

Eccentricity

0.480

Inclination

— °

Year Length

A year here lasts about 1.21 Earth years on a highly eccentric trajectory at a mean orbital distance of 1.1300 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

38.900 m/s

Transit mid-time (BJD)

2,457,177.6900

Long. of periastron (ω)

-55.00°

Angular separation (arcsec)

53.10000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.331

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Marcy et al. 1999

Instrument

HIRES Spectrometer

Publication

1999-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 1998 at W. M. Keck Observatory (2 shown).

HD 168443 b · Gas Giant HD 187123 b · Gas Giant

Host System: HD 210277

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,538 K — cooler than the Sun (5,778 K)

Estimated Age

12.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.070 R☉

Stellar Mass

1.010 M☉

Metallicity [Fe/H]

0.22

Extended Stellar Properties

Surface gravity (log g)

4.380 dex

Stellar density

0.995 g/cm³

Systemic radial velocity

-21.10 km/s

Rotational v·sin i

1.80 km/s

Activity index (log R'HK)

-5.060

Metallicity ratio

[Fe/H]

Distance

21.30 parsec

Light-years 69.47 ly

V-band magnitude

6.54 mag

Voyager-speed travel 1,225,039 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

46.923 mas

Total Proper Motion

458.578 mas/yr

PM Right Ascension

85.46 mas/yr

PM Declination

-450.54 mas/yr

Galactic Cartesian (pc)

x = 0.878 · y = -0.460 · z = -0.131

Equatorial (J2000)

RA 332.37481° · Dec -7.55060°

Galactic ℓ, b

52.348° · -46.966°

Ecliptic λ, β

331.642° · 3.571°

HTM-20 index

-1182790963

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes