Artist impression of HD 28185 b exoplanet
Confirmed Exoplanet Discovered 2001

HD 28185 b

A gas giant orbiting the g-type yellow (sun-like) HD 28185, located approximately 128.4 light-years from Earth.

Image: Wikimedia Commons · CC BY-SA 4.0 · JohnVanVliet

Key parameters at a glance

  • A radius of 12.80 Earth radii
  • A mass of 1,859.30 Earth masses
  • Surface gravity around 11.35 g
  • An orbital period of 385.920 days
  • Semi-major axis 1.0340 AU
  • Distance from Earth 128.44 light-years
  • Earth Similarity Index 0.437
  • Travel time at Voyager 1 speed 2,265,095 years

Context from the literature

HD 28185 b is an extrasolar planet 128 light-years away from Earth in the constellation of Eridanus. The planet was discovered orbiting the Sun-like star HD 28185 in April 2001 as a part of the CORALIE survey for southern extrasolar planets, and its existence was independently confirmed by the Magellan Planet Search Survey in 2008. HD 28185 b orbits its sun in a circular orbit that is at the inner edge of its star's habitable zone.

Excerpted from Wikipedia · full article

1 sibling around HD 28185

HD 28185 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 28185 b this Gas Giant 12.80 1,859.30 385.920 2001
HD 28185 c Gas Giant 12.80 1,906.97 9,090.000 2022

HD 28185 b Planet Profile

Physical Specs

Radius
12.80 R⊕
Radius (Jupiter)
1.140 R♃
Mass
1,859.30 M⊕
Mass (Jupiter)
5.850 M♃
Density
4.87 g/cm³
Surface Gravity
11.35 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.437
HZ Position Unknown
Controversial No

Discovery

Year 2001
Method Radial Velocity
Facility La Silla Observatory
Telescope 1.2 m Leonhard Euler Telescope

Size rank in cohort

Rank by radius

#1063of 1771

top 60.0%

This planet

12.80R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HD 28185 b Jupiter
Radius (R⊕)1.0012.8011.21
Mass (M⊕)1.001,859.30317.83
Density (g/cm³)5.514.871.33
Surface Gravity (g)1.0011.352.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 1,859.296 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 28185

HIP

HIP 20723

TIC

TIC 37947783

Gaia DR2

Gaia DR2 3179384931394690304

Gaia DR3

Gaia DR3 3179384931394690304

System

HD 28185

Percentile among Gas Giant cohort

Radius 12.800 R⊕ · percentile 37 / cohort 1771
Mass 1,859.296 M⊕ · percentile 78 / cohort 1747
Orbital period 385.92 d · percentile 64 / cohort 1533
Distance 39.38 pc · percentile 13 / cohort 1759
ESI 0.437 · percentile 96 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
385.920 days
Semi-major axis
1.0340 AU
Eccentricity
0.063
Inclination
°

Year Length

A year here lasts about 1.06 Earth years on a nearly circular orbit at a mean orbital distance of 1.0340 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

164.800 m/s

Transit mid-time (BJD)

2,455,438.7000

Long. of periastron (ω)

355.10°

Angular separation (arcsec)

26.30000

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.437

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Santos et al. 2001

Instrument

CORALIE Spectrograph

Publication

2001-12

Observation locale

Ground

Host System: HD 28185

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,602 K — cooler than the Sun (5,778 K)

Estimated Age

8.30 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.048 R☉

Stellar Mass

0.974 M☉

Metallicity [Fe/H]

0.19

Extended Stellar Properties

Surface gravity (log g)

4.386 dex

Stellar density

1.117 g/cm³

Systemic radial velocity

50.25 km/s

Rotational v·sin i

2.54 km/s

Metallicity ratio

[Fe/H]

Distance
39.38 parsec
Light-years 128.44 ly
V-band magnitude
7.80 mag
Voyager-speed travel 2,265,095 yr

Multi-band Host Photometry — 11 bands

6.18.58.49B7.80V7.63Gaia7.17TESS6.58J6.29H6.19K6.19W16.14W26.20W36.14W4

Astrometric Data

Parallax

25.364 mas

Total Proper Motion

103.141 mas/yr

PM Right Ascension

84.07 mas/yr

PM Declination

-59.75 mas/yr

Galactic Cartesian (pc)

x = 0.390 · y = 0.902 · z = -0.183

Equatorial (J2000)

RA 66.61005° · Dec -10.55108°

Galactic ℓ, b

205.594° · -36.931°

Ecliptic λ, β

62.661° · -31.797°

HTM-20 index

1040425167

Observation Record

Photometric series

1

RV measurements

3

Archive notes

1

Wikipedia → Image: Wikimedia Commons · JohnVanVliet · CC BY-SA 4.0

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