Key parameters at a glance

A radius of 12.60 Earth radii
A mass of 2,511.48 Earth masses
Surface gravity around 15.82 g
An orbital period of 270.270 days
Semi-major axis 0.8770 AU
Distance from Earth 239.60 light-years
Earth Similarity Index 0.415
Travel time at Voyager 1 speed 4,225,261 years

4 UMa b Planet Profile

Physical Specs

Radius

12.60 R⊕

Radius (Jupiter)

1.120 R♃

Mass

2,511.48 M⊕

Mass (Jupiter)

7.902 M♃

Density

6.90 g/cm³

Surface Gravity

15.82 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.415

HZ Position Unknown

Controversial No

Discovery

Year 2006

Method Radial Velocity

Facility Thueringer Landessternwarte Tautenburg

Telescope 2.0 m Alfred Jensch Telescope

Size rank in cohort

Rank by radius

#1179of 1771

top 66.5%

This planet

12.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Kepler-419 c 12.60 R⊕ 2MASS J04414489+2301513 b 12.60 R⊕ HD 47536 b 12.60 R⊕

Metric	Earth	4 UMa b	Jupiter
Radius (R⊕)	1.00	12.60	11.21
Mass (M⊕)	1.00	2,511.48	317.83
Density (g/cm³)	5.51	6.90	1.33
Surface Gravity (g)	1.00	15.82	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	2,511.480 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 73108

HIP

HIP 42527

TIC

TIC 356478817

Gaia DR2

Gaia DR2 1092230803510960640

Gaia DR3

Gaia DR3 1092230803512999424

System

4 UMa

Percentile among Gas Giant cohort

Radius 12.600 R⊕ · percentile 31 / cohort 1771

Mass 2,511.480 M⊕ · percentile 83 / cohort 1747

Orbital period 270.27 d · percentile 60 / cohort 1533

Distance 73.46 pc · percentile 29 / cohort 1759

ESI 0.415 · percentile 90 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

270.270 days

Semi-major axis

0.8770 AU

Eccentricity

0.453

Inclination

— °

Year Length

A year here lasts approximately 270.27 Earth days (74.0% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.8770 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.415

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Dollinger et al. 2007

Instrument

Coude Echelle Spectrograph

Publication

2007-09

Observation locale

Ground

Host System: 4 UMa

Spectral Class

K-type orange

Effective Temperature

4,415 K — cooler than the Sun (5,778 K)

Estimated Age

4.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

18.110 R☉

Stellar Mass

1.234 M☉

Metallicity [Fe/H]

-0.25

Extended Stellar Properties

Surface gravity (log g)

1.800 dex

Systemic radial velocity

14.62 km/s

Metallicity ratio

[Fe/H]

Distance

73.46 parsec

Light-years 239.60 ly

V-band magnitude

4.58 mag

Voyager-speed travel 4,225,261 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

13.590 mas

Total Proper Motion

66.657 mas/yr

PM Right Ascension

-61.22 mas/yr

PM Declination

26.36 mas/yr

Galactic Cartesian (pc)

x = -0.279 · y = 0.332 · z = 0.901

Equatorial (J2000)

RA 130.05281° · Dec 64.32805°

Galactic ℓ, b

151.359° · 35.957°

Ecliptic λ, β

112.809° · 44.028°

HTM-20 index

2003276221

Similar Worlds

HD 47536 b

Gas Giant · K-type orange

Radius 12.60 R⊕ · 399.7 ly

HD 19615 b

Gas Giant · K-type orange

Radius 12.60 R⊕ · 864.8 ly

HIP 8541 b

Gas Giant · K-type orange

Radius 12.60 R⊕ · 505.9 ly

HIP 35965 b

Gas Giant · K-type orange

Radius 12.60 R⊕ · 163.6 ly

HD 203387 c

Gas Giant · K-type orange

Radius 12.60 R⊕ · 201.4 ly

HD 102329 b

Gas Giant · K-type orange

Radius 12.60 R⊕ · 708.1 ly

Explore Related Categories

Gas Giant Planets Radial Velocity Discoveries Thueringer Landessternwarte Tautenburg Mission K-type orange Hosts