Key parameters at a glance

A radius of 3.05 Earth radii
A mass of 9.53 Earth masses
Surface gravity around 1.02 g
An orbital period of 15.148 days
Semi-major axis 0.1192 AU
Distance from Earth 76.00 light-years
Earth Similarity Index 0.634
Travel time at Voyager 1 speed 1,340,344 years

HD 168009 b Planet Profile

Physical Specs

Radius

3.05 R⊕

Radius (Jupiter)

0.272 R♃

Mass

9.53 M⊕

Mass (Jupiter)

0.030 M♃

Density

1.85 g/cm³

Surface Gravity

1.02 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.634

HZ Position Unknown

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#472of 1978

top 23.8%

This planet

3.05R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1518 b 3.05 R⊕ Kepler-1204 b 3.05 R⊕ Kepler-791 b 3.05 R⊕

Metric	Earth	HD 168009 b	Jupiter
Radius (R⊕)	1.00	3.05	11.21
Mass (M⊕)	1.00	9.53	317.83
Density (g/cm³)	5.51	1.85	1.33
Surface Gravity (g)	1.00	1.02	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	9.535 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 168009

HIP

HIP 89474

TIC

TIC 416117806

Gaia DR2

Gaia DR2 2115351387048328832

Gaia DR3

Gaia DR3 2115351387048328832

System

HD 168009

Percentile among Sub-Neptune cohort

Radius 3.050 R⊕ · percentile 76 / cohort 1978

Mass 9.535 M⊕ · percentile 70 / cohort 1978

Orbital period 15.15 d · percentile 51 / cohort 1946

Distance 23.30 pc · percentile 5 / cohort 1975

ESI 0.634 · percentile 86 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

15.148 days

Semi-major axis

0.1192 AU

Eccentricity

0.120

Inclination

— °

Year Length

A year here lasts approximately 15.15 Earth days (4.1% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1192 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

2.530 m/s

Transit mid-time (BJD)

2,455,201.5600

Long. of periastron (ω)

13.18°

Angular separation (arcsec)

5.12000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.634

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Rosenthal et al. 2021

Instrument

Multiple Instruments

Publication

2021-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at Multiple Observatories (12 shown).

L 98-59 e · Super-Earth GJ 393 b · Rocky Terrestrial HD 164922 e · Sub-Neptune HD 95735 c · Sub-Neptune HD 141004 b · Sub-Neptune HD 107148 c · Neptune-like TOI-178 f · Sub-Neptune TYC 0434-04538-1 b · Gas Giant HIP 56640 b · Gas Giant HD 137496 c · Gas Giant HD 156668 c · Neptune-like HD 145675 c · Gas Giant

Host System: HD 168009

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

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

Estimated Age

9.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.210 R☉

Stellar Mass

0.986 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.265 dex

Stellar density

0.907 g/cm³

Systemic radial velocity

-64.90 km/s

Rotational v·sin i

2.30 km/s

Activity index (log R'HK)

-5.080

Metallicity ratio

[Fe/H]

Distance

23.30 parsec

Light-years 76.00 ly

V-band magnitude

6.30 mag

Voyager-speed travel 1,340,344 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

42.884 mas

Total Proper Motion

138.325 mas/yr

PM Right Ascension

-77.33 mas/yr

PM Declination

-114.69 mas/yr

Galactic Cartesian (pc)

x = 0.048 · y = -0.703 · z = 0.710

Equatorial (J2000)

RA 273.88479° · Dec 45.20882°

Galactic ℓ, b

72.814° · 24.924°

Ecliptic λ, β

277.495° · 68.547°

HTM-20 index

680470449