Key parameters at a glance

A radius of 12.10 Earth radii
A mass of 6,807.63 Earth masses
Surface gravity around 46.50 g
An orbital period of 379.630 days
Semi-major axis 1.4500 AU
Distance from Earth 5,021.86 light-years
Earth Similarity Index 0.284
Travel time at Voyager 1 speed 88,560,435 years

1 sibling around BD+20 2457

BD+20 2457 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
BD+20 2457 b this	Gas Giant	12.10	6,807.63	379.630	—	2009
BD+20 2457 c	Gas Giant	12.40	3,963.17	621.990	—	2009

BD+20 2457 b Planet Profile

Physical Specs

Radius

12.10 R⊕

Radius (Jupiter)

1.080 R♃

Mass

6,807.63 M⊕

Mass (Jupiter)

21.420 M♃

Density

21.10 g/cm³

Surface Gravity

46.50 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.284

HZ Position Unknown

Controversial No

Discovery

Year 2009

Method Radial Velocity

Facility McDonald Observatory

Telescope 9.2 m Hobby-Eberly Telescope

Size rank in cohort

Rank by radius

#1454of 1771

top 82.0%

This planet

12.10R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 106515 A b 12.10 R⊕ HD 165131 b 12.10 R⊕ HD 62364 b 12.10 R⊕

Metric	Earth	BD+20 2457 b	Jupiter
Radius (R⊕)	1.00	12.10	11.21
Mass (M⊕)	1.00	6,807.63	317.83
Density (g/cm³)	5.51	21.10	1.33
Surface Gravity (g)	1.00	46.50	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	6,807.630 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 95359428

Gaia DR2

Gaia DR2 625137162857354880

Gaia DR3

Gaia DR3 625137162857354880

System

BD+20 2457

Percentile among Gas Giant cohort

Radius 12.100 R⊕ · percentile 16 / cohort 1771

Mass 6,807.630 M⊕ · percentile 97 / cohort 1747

Orbital period 379.63 d · percentile 63 / cohort 1533

Distance 1,539.71 pc · percentile 90 / cohort 1759

ESI 0.284 · percentile 53 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

379.630 days

Semi-major axis

1.4500 AU

Eccentricity

0.150

Inclination

— °

Year Length

A year here lasts about 1.04 Earth years on a mildly elliptical path at a mean orbital distance of 1.4500 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.284

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Niedzielski et al. 2009

Instrument

High Resolution Spectrograph

Publication

2009-12

Observation locale

Ground

Discovery cohort

Planets confirmed in 2009 at McDonald Observatory (3 shown).

HD 240210 b · Gas Giant BD+20 2457 c · Gas Giant BD+14 4559 b · Gas Giant

Host System: BD+20 2457

Spectral Class

K-type orange

Effective Temperature

4,137 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

49.000 R☉

Stellar Mass

2.800 M☉

Metallicity [Fe/H]

-1.00

Extended Stellar Properties

Surface gravity (log g)

1.510 dex

Systemic radial velocity

145.77 km/s

Rotational v·sin i

2.50 km/s

Metallicity ratio

[Fe/H]

Distance

1,539.71 parsec

Light-years 5,021.86 ly

V-band magnitude

9.74 mag

Voyager-speed travel 88,560,435 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.599 mas

Total Proper Motion

46.884 mas/yr

PM Right Ascension

-36.08 mas/yr

PM Declination

-29.94 mas/yr

Galactic Cartesian (pc)

x = -0.847 · y = 0.409 · z = 0.340

Equatorial (J2000)

RA 154.18678° · Dec 19.89126°

Galactic ℓ, b

216.045° · 53.952°

Ecliptic λ, β

148.878° · 8.586°

HTM-20 index

-1739616607

Similar Worlds

HD 184010 b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 198.3 ly

tau Gem b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 367.0 ly

KIC 3526061 b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 1,308.6 ly

HIP 948 b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 113.7 ly

HD 109988 b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 138.7 ly

HD 139357 b

Gas Giant · K-type orange

Radius 12.10 R⊕ · 365.6 ly

Explore Related Categories

Gas Giant Planets Radial Velocity Discoveries McDonald Observatory Mission K-type orange Hosts