Key parameters at a glance

A radius of 13.50 Earth radii
A mass of 511.71 Earth masses
Surface gravity around 2.81 g
An orbital period of 258.180 days
Semi-major axis 0.8100 AU
Distance from Earth 85.39 light-years
Earth Similarity Index 0.348
Travel time at Voyager 1 speed 1,505,834 years

1 sibling around HD 134987

HD 134987 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
HD 134987 b this	Gas Giant	13.50	511.71	258.180	—	1999
HD 134987 c	Gas Giant	13.90	260.00	5,000.000	—	2009

HD 134987 b Planet Profile

Physical Specs

Radius

13.50 R⊕

Radius (Jupiter)

1.210 R♃

Mass

511.71 M⊕

Mass (Jupiter)

1.610 M♃

Density

1.14 g/cm³

Surface Gravity

2.81 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.348

HZ Position Unknown

Controversial No

Discovery

Year 1999

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#671of 1771

top 37.8%

This planet

13.50R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 45350 b 13.50 R⊕ HD 82943 b 13.50 R⊕ HD 27442 b 13.50 R⊕

Metric	Earth	HD 134987 b	Jupiter
Radius (R⊕)	1.00	13.50	11.21
Mass (M⊕)	1.00	511.71	317.83
Density (g/cm³)	5.51	1.14	1.33
Surface Gravity (g)	1.00	2.81	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	511.706 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 134987

HIP

HIP 74500

TIC

TIC 61397572

Gaia DR2

Gaia DR2 6226694571859532800

Gaia DR3

Gaia DR3 6226694571859532800

System

HD 134987

Percentile among Gas Giant cohort

Radius 13.500 R⊕ · percentile 59 / cohort 1771

Mass 511.706 M⊕ · percentile 49 / cohort 1747

Orbital period 258.18 d · percentile 59 / cohort 1533

Distance 26.18 pc · percentile 6 / cohort 1759

ESI 0.348 · percentile 70 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

258.180 days

Semi-major axis

0.8100 AU

Eccentricity

0.230

Inclination

— °

Year Length

A year here lasts approximately 258.18 Earth days (70.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.8100 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

49.500 m/s

Transit mid-time (BJD)

2,452,704.4200

Long. of periastron (ω)

352.70°

Angular separation (arcsec)

30.90000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.348

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Vogt et al. 2000

Instrument

HIRES Spectrometer

Publication

2000-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 1999 at W. M. Keck Observatory (4 shown).

HD 10697 b · Gas Giant HD 222582 b · Gas Giant HD 177830 b · Gas Giant HD 209458 b · Gas Giant

Host System: HD 134987

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,736 K — cooler than the Sun (5,778 K)

Estimated Age

8.40 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.220 R☉

Stellar Mass

1.100 M☉

Metallicity [Fe/H]

0.28

Extended Stellar Properties

Surface gravity (log g)

4.310 dex

Stellar density

0.683 g/cm³

Systemic radial velocity

5.21 km/s

Rotational v·sin i

2.17 km/s

Activity index (log R'HK)

-5.090

Metallicity ratio

[Fe/H]

Distance

26.18 parsec

Light-years 85.39 ly

V-band magnitude

6.47 mag

Voyager-speed travel 1,505,834 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

38.168 mas

Total Proper Motion

407.303 mas/yr

PM Right Ascension

-400.31 mas/yr

PM Declination

-75.16 mas/yr

Galactic Cartesian (pc)

x = -0.601 · y = -0.676 · z = -0.428

Equatorial (J2000)

RA 228.36754° · Dec -25.30967°

Galactic ℓ, b

339.184° · 27.387°

Ecliptic λ, β

232.752° · -7.092°

HTM-20 index

641096478

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes