Key parameters at a glance

A radius of 7.43 Earth radii
A mass of 43.22 Earth masses
Surface gravity around 0.78 g
An orbital period of 99.622 days
Semi-major axis 0.4260 AU
Distance from Earth 79.27 light-years
Earth Similarity Index 0.372
Travel time at Voyager 1 speed 1,398,000 years

HD 199509 b Planet Profile

Physical Specs

Radius

7.43 R⊕

Radius (Jupiter)

0.663 R♃

Mass

43.22 M⊕

Mass (Jupiter)

0.136 M♃

Density

0.58 g/cm³

Surface Gravity

0.78 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.372

HZ Position Unknown

Controversial No

Discovery

Year 2022

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#180of 574

top 31.2%

This planet

7.43R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

HD 89345 b 7.40 R⊕ Kepler-682 b 7.37 R⊕ K2-24 c 7.50 R⊕

Metric	Earth	HD 199509 b	Jupiter
Radius (R⊕)	1.00	7.43	11.21
Mass (M⊕)	1.00	43.22	317.83
Density (g/cm³)	5.51	0.58	1.33
Surface Gravity (g)	1.00	0.78	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	43.225 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 199509

HIP

HIP 104436

TIC

TIC 401701660

Gaia DR2

Gaia DR2 6348288635054855680

Gaia DR3

Gaia DR3 6348288635054855680

System

HIP 104436

Percentile among Neptune-like cohort

Radius 7.430 R⊕ · percentile 69 / cohort 574

Mass 43.225 M⊕ · percentile 65 / cohort 574

Orbital period 99.62 d · percentile 82 / cohort 524

Distance 24.31 pc · percentile 8 / cohort 572

ESI 0.372 · percentile 68 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

99.622 days

Semi-major axis

0.4260 AU

Eccentricity

0.373

Inclination

— °

Year Length

A year here lasts approximately 99.62 Earth days (27.3% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.4260 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.372

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Feng et al. 2022

Instrument

Multiple Instruments

Publication

2022-09

Observation locale

Ground

Discovery cohort

Planets confirmed in 2022 at Multiple Observatories (12 shown).

Kepler-138 e · Rocky Terrestrial HD 93351 b · Super-Earth GJ 1002 b · Rocky Terrestrial GJ 2030 b · Sub-Neptune GJ 3929 c · Sub-Neptune HD 217786 c · Sub-Neptune GJ 1002 c · Rocky Terrestrial HD 155918 b · Sub-Neptune HD 213519 b · Sub-Neptune HD 191939 g · Sub-Neptune GJ 514 b · Sub-Neptune HD 12235 b · Sub-Neptune

Host System: HD 199509

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,796 K — hotter than the Sun (5,778 K)

Estimated Age

1.60 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.920 R☉

Stellar Mass

1.040 M☉

Metallicity [Fe/H]

-0.31

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

2.010 g/cm³

Systemic radial velocity

-21.60 km/s

Rotational v·sin i

0.90 km/s

Activity index (log R'HK)

-4.810

Metallicity ratio

[M/H]

Distance

24.31 parsec

Light-years 79.27 ly

V-band magnitude

6.98 mag

Voyager-speed travel 1,398,000 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

41.114 mas

Total Proper Motion

269.783 mas/yr

PM Right Ascension

264.00 mas/yr

PM Declination

-55.54 mas/yr

Galactic Cartesian (pc)

x = 0.102 · y = -0.094 · z = -0.990

Equatorial (J2000)

RA 317.34456° · Dec -82.02749°

Galactic ℓ, b

310.632° · -31.431°

Ecliptic λ, β

281.990° · -60.602°

HTM-20 index

1083552683