Key parameters at a glance

A radius of 12.78 Earth radii
A mass of 378.20 Earth masses
Surface gravity around 2.32 g
An orbital period of 4.188 days
Semi-major axis 0.0515 AU
Equilibrium temperature 1,230 K (957 °C)
Distance from Earth 900.88 light-years
Earth Similarity Index 0.118
Travel time at Voyager 1 speed 15,886,996 years

XO-5 b Planet Profile

Physical Specs

Radius

12.78 R⊕

Radius (Jupiter)

1.140 R♃

Mass

378.20 M⊕

Mass (Jupiter)

1.190 M♃

Density

1.06 g/cm³

Surface Gravity

2.32 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.118

HZ Position Inner

Controversial No

Discovery

Year 2008

Method Transit

Facility XO

Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#1117of 1771

top 63.0%

This planet

12.78R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

WASP-97 b 12.78 R⊕ XO-1 b 12.78 R⊕ TOI-1820 b 12.78 R⊕

Metric	Earth	XO-5 b	Jupiter
Radius (R⊕)	1.00	12.78	11.21
Mass (M⊕)	1.00	378.20	317.83
Density (g/cm³)	5.51	1.06	1.33
Surface Gravity (g)	1.00	2.32	2.53
Insolation (S⊕)	1.00	397.48	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	378.200 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	331.815 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 9155187

Gaia DR2

Gaia DR2 920308932010648448

Gaia DR3

Gaia DR3 920308932010648448

System

XO-5

Percentile among Gas Giant cohort

Radius 12.780 R⊕ · percentile 37 / cohort 1771

Mass 378.200 M⊕ · percentile 40 / cohort 1747

Orbital period 4.19 d · percentile 31 / cohort 1533

Distance 276.21 pc · percentile 58 / cohort 1759

ESI 0.118 · percentile 31 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.188 days

Semi-major axis

0.0515 AU

Eccentricity

0.000

Inclination

86.80 °

Year Length

A year here lasts approximately 4.19 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0515 AU.

Transit Fingerprint

Depth

1.080 %

Duration

3.118 h

Impact parameter b

0.550

Rp / R★

0.103900

Transit midpoint (BJD)

2,456,864.3129

Photometric dip

Transit produces a flux drop of 10,800 ppm lasting ≈ 3.12 h.

Extended Orbital Architecture

Planet / star radius ratio

0.103900

Semi-major axis / stellar radius

9.850

Impact parameter (b)

0.550

RV semi-amplitude (K)

146.000 m/s

Transit mid-time (BJD)

2,456,864.3129

Long. of periastron (ω)

331.01°

Angular separation (arcsec)

0.18600

Eq. Temperature

1,230K

(957 °C)

Insolation (S⊕)

397.48

Earth = 1.00

Earth Similarity (ESI)

0.118

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Burke et al. 2008

Instrument

Apogee CCD Array

Publication

2008-10

Observation locale

Ground

Host System: XO-5

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,430 K — cooler than the Sun (5,778 K)

Estimated Age

8.50 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.130 R☉

Stellar Mass

1.040 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.350 dex

Stellar density

1.010 g/cm³

Systemic radial velocity

-9.84 km/s

Rotational v·sin i

1.80 km/s

Metallicity ratio

[Fe/H]

Distance

276.21 parsec

Light-years 900.88 ly

V-band magnitude

12.20 mag

Voyager-speed travel 15,886,996 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

3.592 mas

Total Proper Motion

32.169 mas/yr

PM Right Ascension

-21.53 mas/yr

PM Declination

-23.91 mas/yr

Galactic Cartesian (pc)

x = -0.349 · y = 0.693 · z = 0.631

Equatorial (J2000)

RA 116.71639° · Dec 39.09447°

Galactic ℓ, b

180.626° · 26.934°

Ecliptic λ, β

111.472° · 17.626°

HTM-20 index

-1704502734