Confirmed Exoplanet Discovered 2010

HR 8799 e

A gas giant orbiting the a-type white HR 8799, located approximately 134.5 light-years from Earth.

Key parameters at a glance

  • A radius of 13.11 Earth radii
  • A mass of 3,178.30 Earth masses
  • Surface gravity around 18.48 g
  • An orbital period of 20,815.600 days
  • Semi-major axis 16.4000 AU
  • Equilibrium temperature 1,150 K (877 °C)
  • Distance from Earth 134.52 light-years
  • Earth Similarity Index 0.139
  • Travel time at Voyager 1 speed 2,372,262 years

3 siblings around HR 8799

HR 8799 e shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
HR 8799 e this Gas Giant 13.11 3,178.30 20,815.600 1,150 2010
HR 8799 d Gas Giant 13.00 3,000.00 37,000.000 1,300 2008
HR 8799 c Gas Giant 13.00 3,000.00 69,000.000 1,200 2008
HR 8799 b Gas Giant 13.00 2,000.00 170,000.000 1,200 2008

HR 8799 e Planet Profile

Physical Specs

Radius
13.11 R⊕
Radius (Jupiter)
1.170 R♃
Mass
3,178.30 M⊕
Mass (Jupiter)
10.000 M♃
Density
7.74 g/cm³
Surface Gravity
18.48 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.139
HZ Position Unknown
Controversial No

Discovery

Year 2010
Method Imaging
Facility W. M. Keck Observatory
Telescope 10 m Keck II Telescope

Size rank in cohort

Rank by radius

#905of 1771

top 51.0%

This planet

13.11R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HAT-P-29 b 13.11 R⊕ TOI-677 b 13.11 R⊕ CoRoT-16 b 13.11 R⊕
Metric Earth HR 8799 e Jupiter
Radius (R⊕)1.0013.1111.21
Mass (M⊕)1.003,178.30317.83
Density (g/cm³)5.517.741.33
Surface Gravity (g)1.0018.482.53
Insolation (S⊕)1.00—0.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 3,178.300 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

HD

HD 218396

HIP

HIP 114189

TIC

TIC 245368902

Gaia DR2

Gaia DR2 2832463659640297472

Gaia DR3

Gaia DR3 2832463659640297472

System

HR 8799

Percentile among Gas Giant cohort

Radius 13.115 R⊕ · percentile 49 / cohort 1771
Mass 3,178.300 M⊕ · percentile 88 / cohort 1747
Orbital period 20,815.60 d · percentile 98 / cohort 1533
Distance 41.24 pc · percentile 15 / cohort 1759
ESI 0.139 · percentile 35 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
20,815.600 days
Semi-major axis
16.4000 AU
Eccentricity
0.150
Inclination
25.00 °

Year Length

A year here lasts about 56.99 Earth years on a mildly elliptical path at a mean orbital distance of 16.4000 AU.

Eq. Temperature

1,150K

(877 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.139

0 = alien, 1 = Earth-identical

Insufficient insolation data — the dayside is scorched.

Detection Signatures

Astrometry

Positional wobble of the host star was measured.

Direct imaging

The planet has been imaged directly (rare).

Discovery Paper

Primary reference

Marois et al. 2010

Instrument

NIRC2 Camera

Publication

2010-12

Observation locale

Ground

Discovery cohort

Planets confirmed in 2010 at W. M. Keck Observatory (12 shown).

HD 156668 b · Super-Earth HD 1461 b · Sub-Neptune GJ 876 e · Sub-Neptune HAT-P-17 c · Gas Giant HD 97658 b · Sub-Neptune HD 163607 c · Gas Giant HD 177830 c · Neptune-like HD 218566 b · Neptune-like HD 102956 b · Gas Giant HD 163607 b · Gas Giant GJ 1148 b · Gas Giant HD 31253 b · Gas Giant

Host System: HR 8799

Spectral Class

A-type white

Effective Temperature

7,400 K — hotter than the Sun (5,778 K)

Estimated Age

0.03 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.493 R☉

Stellar Mass

1.510 M☉

Metallicity [Fe/H]

-0.50

Extended Stellar Properties

Surface gravity (log g)

4.000 dex

Stellar density

0.682 g/cm³

Rotational v·sin i

34.79 km/s

Metallicity ratio

[Fe/H]

Distance
41.24 parsec
Light-years 134.52 ly
V-band magnitude
5.98 mag
Voyager-speed travel 2,372,262 yr

Multi-band Host Photometry — 11 bands

4.96.26.24B5.98V5.91Gaia5.71TESS5.38J5.28H5.24K5.19W15.05W25.21W34.85W4

Astrometric Data

Parallax

24.218 mas

Total Proper Motion

119.069 mas/yr

PM Right Ascension

108.30 mas/yr

PM Declination

-49.48 mas/yr

Galactic Cartesian (pc)

x = 0.908 · y = -0.212 · z = 0.361

Equatorial (J2000)

RA 346.87015° · Dec 21.13404°

Galactic ℓ, b

92.765° · -35.576°

Ecliptic λ, β

356.784° · 24.524°

HTM-20 index

590321788

Similar Worlds

HR 8799 b

Gas Giant · A-type white

Radius 13.00 R⊕ · 134.5 ly

HR 8799 c

Gas Giant · A-type white

Radius 13.00 R⊕ · 134.5 ly

HR 8799 d

Gas Giant · A-type white

Radius 13.00 R⊕ · 134.5 ly

HD 95086 b

Gas Giant · A-type white

Radius 12.90 R⊕ · 281.2 ly

Artist impression of WD 0806-661 b exoplanet

WD 0806-661 b

Gas Giant · A-type white

Radius 12.60 R⊕ · 62.8 ly

TOI-1994 b

Gas Giant · A-type white

Radius 13.67 R⊕ · 1,681.7 ly

Explore Related Categories

Gas Giant Planets Imaging Discoveries W. M. Keck Observatory Mission A-type white Hosts