Key parameters at a glance

A radius of 12.40 Earth radii
A mass of 3,963.17 Earth masses
Surface gravity around 25.78 g
An orbital period of 621.990 days
Semi-major axis 2.0100 AU
Distance from Earth 5,021.86 light-years
Earth Similarity Index 0.354
Travel time at Voyager 1 speed 88,560,435 years

1 sibling around BD+20 2457

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

BD+20 2457 c Planet Profile

Physical Specs

Radius

12.40 R⊕

Radius (Jupiter)

1.100 R♃

Mass

3,963.17 M⊕

Mass (Jupiter)

12.470 M♃

Density

11.40 g/cm³

Surface Gravity

25.78 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.354

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

#1298of 1771

top 73.2%

This planet

12.40R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 110014 b 12.40 R⊕ CFBDSIR J145829+101343 b 12.40 R⊕ MOA-2010-BLG-073L b 12.40 R⊕

Metric	Earth	BD+20 2457 c	Jupiter
Radius (R⊕)	1.00	12.40	11.21
Mass (M⊕)	1.00	3,963.17	317.83
Density (g/cm³)	5.51	11.40	1.33
Surface Gravity (g)	1.00	25.78	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	3,963.170 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 12.400 R⊕ · percentile 25 / cohort 1771

Mass 3,963.170 M⊕ · percentile 91 / cohort 1747

Orbital period 621.99 d · percentile 71 / cohort 1533

Distance 1,539.71 pc · percentile 90 / cohort 1759

ESI 0.354 · percentile 72 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

621.990 days

Semi-major axis

2.0100 AU

Eccentricity

0.180

Inclination

— °

Year Length

A year here lasts about 1.70 Earth years on a mildly elliptical path at a mean orbital distance of 2.0100 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.354

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+14 4559 b · Gas Giant BD+20 2457 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 87816 c

Gas Giant · K-type orange

Radius 12.40 R⊕ · 434.5 ly

HD 95127 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 2,206.7 ly

HD 16905 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 129.6 ly

Gaia-4 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 239.7 ly

HD 110014 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 328.6 ly

TYC 4282-00605-1 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 1,513.8 ly

Explore Related Categories

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