Key parameters at a glance

A radius of 10.90 Earth radii
A mass of 82.64 Earth masses
Surface gravity around 0.70 g
An orbital period of 18.157 days
Semi-major axis 0.1300 AU
Distance from Earth 493.79 light-years
Earth Similarity Index 0.289
Travel time at Voyager 1 speed 8,708,051 years

1 sibling around XO-2 S

XO-2 S 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
XO-2 S b this	Gas Giant	10.90	82.64	18.157	—	2014
XO-2 S c	Gas Giant	13.60	435.41	120.800	—	2014

XO-2 S b Planet Profile

Physical Specs

Radius

10.90 R⊕

Radius (Jupiter)

0.971 R♃

Mass

82.64 M⊕

Mass (Jupiter)

0.260 M♃

Density

0.35 g/cm³

Surface Gravity

0.70 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.289

HZ Position Unknown

Controversial No

Discovery

Year 2014

Method Radial Velocity

Facility Roque de los Muchachos Observatory

Telescope 3.58 m Telescopio Nazionale Galileo

Size rank in cohort

Rank by radius

#1672of 1771

top 94.4%

This planet

10.90R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

OGLE-2018-BLG-0799L b 10.90 R⊕ HD 142 A d 10.90 R⊕ HD 16141 b 10.90 R⊕

Metric	Earth	XO-2 S b	Jupiter
Radius (R⊕)	1.00	10.90	11.21
Mass (M⊕)	1.00	82.64	317.83
Density (g/cm³)	5.51	0.35	1.33
Surface Gravity (g)	1.00	0.70	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	82.636 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 356473029

Gaia DR2

Gaia DR2 934346740559239296

Gaia DR3

Gaia DR3 934346740559239296

System

XO-2

Percentile among Gas Giant cohort

Radius 10.900 R⊕ · percentile 5 / cohort 1771

Mass 82.636 M⊕ · percentile 3 / cohort 1747

Orbital period 18.16 d · percentile 47 / cohort 1533

Distance 151.40 pc · percentile 44 / cohort 1759

ESI 0.289 · percentile 55 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

18.157 days

Semi-major axis

0.1300 AU

Eccentricity

0.180

Inclination

— °

Year Length

A year here lasts approximately 18.16 Earth days (5.0% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1300 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.289

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Desidera et al. 2014

Instrument

HARPS-N Spectrograph

Publication

2014-07

Observation locale

Ground

Host System: XO-2 S

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,399 K — cooler than the Sun (5,778 K)

Estimated Age

7.10 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.000 R☉

Stellar Mass

0.980 M☉

Metallicity [Fe/H]

0.39

Extended Stellar Properties

Surface gravity (log g)

4.430 dex

Stellar density

1.542 g/cm³

Systemic radial velocity

46.54 km/s

Rotational v·sin i

1.70 km/s

Metallicity ratio

[Fe/H]

Distance

151.40 parsec

Light-years 493.79 ly

V-band magnitude

11.20 mag

Voyager-speed travel 8,708,051 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

6.577 mas

Total Proper Motion

157.157 mas/yr

PM Right Ascension

-29.32 mas/yr

PM Declination

-154.40 mas/yr

Galactic Cartesian (pc)

x = -0.291 · y = 0.570 · z = 0.768

Equatorial (J2000)

RA 117.03098° · Dec 50.21691°

Galactic ℓ, b

168.300° · 29.330°

Ecliptic λ, β

109.335° · 28.577°

HTM-20 index

-142088187