Confirmed Exoplanet Discovered 2017

HD 27894 d

A gas giant orbiting the k-type orange HD 27894, located approximately 142.9 light-years from Earth.

Key parameters at a glance

  • A radius of 12.70 Earth radii
  • A mass of 2,063.66 Earth masses
  • Surface gravity around 12.79 g
  • An orbital period of 5,019.542 days
  • Semi-major axis 5.3620 AU
  • Distance from Earth 142.93 light-years
  • Earth Similarity Index 0.442
  • Travel time at Voyager 1 speed 2,520,502 years

Context from the literature

HD 27894 is a single star with a system of orbiting exoplanets, located in the southern constellation of Reticulum. It is too faint to be seen with the naked eye at an apparent visual magnitude of 9.36. This system lies at a distance of 142.5 light years from the Sun, as determined via parallax measurements, and is drifting further away with a radial velocity of 83 km/s.

Excerpted from Wikipedia · full article

2 siblings around HD 27894

HD 27894 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
HD 27894 b Gas Giant 14.10 196.74 18.019 2005
HD 27894 c Neptune-like 8.24 51.49 36.070 2017
HD 27894 d this Gas Giant 12.70 2,063.66 5,019.542 2017

HD 27894 d Planet Profile

Physical Specs

Radius
12.70 R⊕
Radius (Jupiter)
1.130 R♃
Mass
2,063.66 M⊕
Mass (Jupiter)
6.493 M♃
Density
5.54 g/cm³
Surface Gravity
12.79 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.442
HZ Position Unknown
Controversial No

Discovery

Year 2017
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#1130of 1771

top 63.7%

This planet

12.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HD 27894 d Jupiter
Radius (R⊕)1.0012.7011.21
Mass (M⊕)1.002,063.66317.83
Density (g/cm³)5.515.541.33
Surface Gravity (g)1.0012.792.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 2,063.660 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 1,721.049 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 27894

HIP

HIP 20277

TIC

TIC 396697266

Gaia DR2

Gaia DR2 4678605152248591488

Gaia DR3

Gaia DR3 4678605152248591488

System

HD 27894

Percentile among Gas Giant cohort

Radius 12.700 R⊕ · percentile 34 / cohort 1771
Mass 2,063.660 M⊕ · percentile 80 / cohort 1747
Orbital period 5,019.54 d · percentile 92 / cohort 1533
Distance 43.82 pc · percentile 16 / cohort 1759
ESI 0.442 · percentile 98 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
5,019.542 days
Semi-major axis
5.3620 AU
Eccentricity
0.343
Inclination
101.52 °

Year Length

A year here lasts about 13.74 Earth years on a highly eccentric trajectory at a mean orbital distance of 5.3620 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.442

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

Trifonov et al. 2017

Instrument

HARPS Spectrograph

Publication

2017-06

Observation locale

Ground

Host System: HD 27894

Spectral Class

K-type orange

Effective Temperature

4,875 K — cooler than the Sun (5,778 K)

Estimated Age

3.90 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.892 R☉

Stellar Mass

0.810 M☉

Metallicity [Fe/H]

0.30

Extended Stellar Properties

Surface gravity (log g)

4.220 dex

Stellar density

1.846 g/cm³

Systemic radial velocity

82.90 km/s

Rotational v·sin i

1.50 km/s

Rotation period

44.00 days

Metallicity ratio

[Fe/H]

Distance
43.82 parsec
Light-years 142.93 ly
V-band magnitude
9.36 mag
Voyager-speed travel 2,520,502 yr

Multi-band Host Photometry — 11 bands

6.910.310.31B9.36V9.07Gaia8.46TESS7.64J7.17H7.07K6.94W17.08W27.05W36.99W4

Astrometric Data

Parallax

22.791 mas

Total Proper Motion

325.715 mas/yr

PM Right Ascension

182.31 mas/yr

PM Declination

269.91 mas/yr

Galactic Cartesian (pc)

x = 0.213 · y = 0.462 · z = -0.861

Equatorial (J2000)

RA 65.19757° · Dec -59.40968°

Galactic ℓ, b

270.100° · -42.009°

Ecliptic λ, β

20.873° · -76.793°

HTM-20 index

1725638851

Observation Record

Photometric series

1

RV measurements

1

Archive notes

1

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