Key parameters at a glance

A radius of 13.40 Earth radii
A mass of 626.13 Earth masses
Surface gravity around 3.49 g
An orbital period of 6.277 days
Semi-major axis 0.0700 AU
Distance from Earth 198.45 light-years
Earth Similarity Index 0.364
Travel time at Voyager 1 speed 3,499,642 years

1 sibling around HD 68988

HD 68988 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 68988 b this	Gas Giant	13.40	626.13	6.277	—	2001
HD 68988 c	Gas Giant	12.20	4,776.96	16,000.000	—	2021

HD 68988 b Planet Profile

Physical Specs

Radius

13.40 R⊕

Radius (Jupiter)

1.200 R♃

Mass

626.13 M⊕

Mass (Jupiter)

1.970 M♃

Density

1.43 g/cm³

Surface Gravity

3.49 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.364

HZ Position Unknown

Controversial No

Discovery

Year 2001

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#730of 1771

top 41.2%

This planet

13.40R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 114783 c 13.40 R⊕ HIP 79431 b 13.40 R⊕ HD 82943 c 13.40 R⊕

Metric	Earth	HD 68988 b	Jupiter
Radius (R⊕)	1.00	13.40	11.21
Mass (M⊕)	1.00	626.13	317.83
Density (g/cm³)	5.51	1.43	1.33
Surface Gravity (g)	1.00	3.49	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	626.125 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 68988

HIP

HIP 40687

TIC

TIC 73312938

Gaia DR2

Gaia DR2 1090159839002347136

Gaia DR3

Gaia DR3 1090159839002347136

System

HD 68988

Percentile among Gas Giant cohort

Radius 13.400 R⊕ · percentile 56 / cohort 1771

Mass 626.125 M⊕ · percentile 54 / cohort 1747

Orbital period 6.28 d · percentile 40 / cohort 1533

Distance 60.84 pc · percentile 25 / cohort 1759

ESI 0.364 · percentile 75 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

6.277 days

Semi-major axis

0.0700 AU

Eccentricity

0.120

Inclination

83.00 °

Year Length

A year here lasts approximately 6.28 Earth days (1.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0700 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

184.700 m/s

Transit mid-time (BJD)

2,451,549.7170

Long. of periastron (ω)

40.40°

Angular separation (arcsec)

1.15000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.364

0 = alien, 1 = Earth-identical

Detection Signatures

Radial velocity

Stellar wobble has been measured spectroscopically.

Astrometry

Positional wobble of the host star was measured.

Discovery Paper

Primary reference

Vogt et al. 2002

Instrument

Multiple Instruments

Publication

2002-03

Observation locale

Ground

Host System: HD 68988

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,932 K — hotter than the Sun (5,778 K)

Estimated Age

6.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.190 R☉

Stellar Mass

1.280 M☉

Metallicity [Fe/H]

0.35

Extended Stellar Properties

Surface gravity (log g)

4.400 dex

Stellar density

0.771 g/cm³

Systemic radial velocity

-69.50 km/s

Rotational v·sin i

2.84 km/s

Activity index (log R'HK)

-5.040

Metallicity ratio

[Fe/H]

Distance

60.84 parsec

Light-years 198.45 ly

V-band magnitude

8.20 mag

Voyager-speed travel 3,499,642 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

16.407 mas

Total Proper Motion

131.851 mas/yr

PM Right Ascension

128.33 mas/yr

PM Declination

30.27 mas/yr

Galactic Cartesian (pc)

x = -0.271 · y = 0.393 · z = 0.878

Equatorial (J2000)

RA 124.59354° · Dec 61.46085°

Galactic ℓ, b

155.263° · 33.920°

Ecliptic λ, β

110.897° · 40.508°

HTM-20 index

-286599229

Observation Record

Photometric series

RV measurements

Stellar spectra