Confirmed Exoplanet Discovered 2018

HAT-P-11 c

A gas giant orbiting the k-type orange HAT-P-11, located approximately 123.2 light-years from Earth.

Key parameters at a glance

  • A radius of 13.20 Earth radii
  • A mass of 851.78 Earth masses
  • Surface gravity around 4.89 g
  • An orbital period of 3,361.000 days
  • Semi-major axis 4.1000 AU
  • Distance from Earth 123.17 light-years
  • Earth Similarity Index 0.389
  • Travel time at Voyager 1 speed 2,172,135 years

1 sibling around HAT-P-11

HAT-P-11 c 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
HAT-P-11 b Neptune-like 4.36 25.00 4.888 838 2008
HAT-P-11 c this Gas Giant 13.20 851.78 3,361.000 2018

HAT-P-11 c Planet Profile

Physical Specs

Radius
13.20 R⊕
Radius (Jupiter)
1.180 R♃
Mass
851.78 M⊕
Mass (Jupiter)
2.680 M♃
Density
2.04 g/cm³
Surface Gravity
4.89 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.389
HZ Position Unknown
Controversial No

Discovery

Year 2018
Method Radial Velocity
Facility W. M. Keck Observatory
Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#847of 1771

top 47.8%

This planet

13.20R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HAT-P-11 c Jupiter
Radius (R⊕)1.0013.2011.21
Mass (M⊕)1.00851.78317.83
Density (g/cm³)5.512.041.33
Surface Gravity (g)1.004.892.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 851.780 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 507.000 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 97657

TIC

TIC 28230919

Gaia DR2

Gaia DR2 2086512227851023872

Gaia DR3

Gaia DR3 2086512227851023872

System

HAT-P-11

Percentile among Gas Giant cohort

Radius 13.200 R⊕ · percentile 49 / cohort 1771
Mass 851.780 M⊕ · percentile 63 / cohort 1747
Orbital period 3,361.00 d · percentile 89 / cohort 1533
Distance 37.76 pc · percentile 12 / cohort 1759
ESI 0.389 · percentile 82 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
3,361.000 days
Semi-major axis
4.1000 AU
Eccentricity
0.652
Inclination
33.10 °

Year Length

A year here lasts about 9.20 Earth years on a highly eccentric trajectory at a mean orbital distance of 4.1000 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

30.100 m/s

Transit mid-time (BJD)

2,456,746.0000

Long. of periastron (ω)

142.10°

Angular separation (arcsec)

109.00000

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.389

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

Yee et al. 2018

Instrument

HIRES Spectrometer

Publication

2018-06

Observation locale

Ground

Host System: HAT-P-11

Spectral Class

K-type orange

Effective Temperature

4,653 K — cooler than the Sun (5,778 K)

Estimated Age

2.69 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.683 R☉

Stellar Mass

0.811 M☉

Metallicity [Fe/H]

0.31

Extended Stellar Properties

Surface gravity (log g)

4.663 dex

Stellar density

3.700 g/cm³

Systemic radial velocity

-63.24 km/s

Rotational v·sin i

0.67 km/s

Rotation period

30.50 days

Activity index (log R'HK)

-4.350

Metallicity ratio

[Fe/H]

Distance
37.76 parsec
Light-years 123.17 ly
V-band magnitude
9.46 mag
Voyager-speed travel 2,172,135 yr

Multi-band Host Photometry — 14 bands

6.910.710.56B9.46V9.15Gaia9.17Kepler8.51TESS10.67Sloan g9.48Sloan r7.61J7.13H7.01K6.92W17.00W26.97W36.87W4

Astrometric Data

Parallax

26.451 mas

Total Proper Motion

264.869 mas/yr

PM Right Ascension

125.98 mas/yr

PM Declination

232.99 mas/yr

Galactic Cartesian (pc)

x = 0.311 · y = -0.591 · z = 0.744

Equatorial (J2000)

RA 297.71018° · Dec 48.08186°

Galactic ℓ, b

81.835° · 10.772°

Ecliptic λ, β

321.547° · 66.630°

HTM-20 index

2052377588

Observation Record

Photometric series

13

RV measurements

1

Archive notes

3

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