Confirmed Exoplanet Discovered 2013

HD 109271 c

A neptune-like orbiting the g-type yellow (sun-like) HD 109271, located approximately 182.2 light-years from Earth.

Key parameters at a glance

  • A radius of 5.27 Earth radii
  • A mass of 24.15 Earth masses
  • Surface gravity around 0.87 g
  • An orbital period of 30.930 days
  • Semi-major axis 0.1960 AU
  • Distance from Earth 182.23 light-years
  • Earth Similarity Index 0.462
  • Travel time at Voyager 1 speed 3,213,601 years

Context from the literature

HD 109271 is a wide binary star system in the constellation of Virgo. The brighter member of the binary has a pair of orbiting exoplanets. With an apparent visual magnitude of 8.05, it cannot be seen with the naked eye. Parallax measurements made by Gaia put the star at a distance of 181 light-years away from the Sun, but it is drifting closer with a radial velocity of −5 km/s. The system shows a high proper motion, traversing the celestial sphere at an angular rate of 0.232 arcsec yr−1.

Excerpted from Wikipedia · full article

1 sibling around HD 109271

HD 109271 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
HD 109271 b Neptune-like 4.31 17.16 7.854 2013
HD 109271 c this Neptune-like 5.27 24.15 30.930 2013

HD 109271 c Planet Profile

Physical Specs

Radius
5.27 R⊕
Radius (Jupiter)
0.470 R♃
Mass
24.15 M⊕
Mass (Jupiter)
0.076 M♃
Density
0.91 g/cm³
Surface Gravity
0.87 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.462
HZ Position Unknown
Controversial No

Discovery

Year 2013
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#346of 574

top 60.1%

This planet

5.27R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth HD 109271 c Jupiter
Radius (R⊕)1.005.2711.21
Mass (M⊕)1.0024.15317.83
Density (g/cm³)5.510.911.33
Surface Gravity (g)1.000.872.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 24.154 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 109271

HIP

HIP 61300

TIC

TIC 429301734

Gaia DR2

Gaia DR2 3578137838413202688

Gaia DR3

Gaia DR3 3578137842709899648

System

HD 109271

Percentile among Neptune-like cohort

Radius 5.270 R⊕ · percentile 40 / cohort 574
Mass 24.154 M⊕ · percentile 41 / cohort 574
Orbital period 30.93 d · percentile 60 / cohort 524
Distance 55.87 pc · percentile 17 / cohort 572
ESI 0.462 · percentile 83 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
30.930 days
Semi-major axis
0.1960 AU
Eccentricity
0.150
Inclination
°

Year Length

A year here lasts approximately 30.93 Earth days (8.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1960 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.462

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Lo Curto et al. 2013

Instrument

HARPS Spectrograph

Publication

2013-03

Observation locale

Ground

Host System: HD 109271

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,783 K — hotter than the Sun (5,778 K)

Estimated Age

7.30 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.295 R☉

Stellar Mass

1.047 M☉

Metallicity [Fe/H]

0.10

Extended Stellar Properties

Surface gravity (log g)

4.280 dex

Stellar density

0.744 g/cm³

Systemic radial velocity

-4.90 km/s

Rotational v·sin i

2.70 km/s

Metallicity ratio

[Fe/H]

Distance
55.87 parsec
Light-years 182.23 ly
V-band magnitude
8.04 mag
Voyager-speed travel 3,213,601 yr

Multi-band Host Photometry — 11 bands

6.48.78.71B8.04V7.88Gaia7.44TESS6.86J6.56H6.50K6.50W16.41W26.50W36.45W4

Astrometric Data

Parallax

17.870 mas

Total Proper Motion

187.983 mas/yr

PM Right Ascension

-169.69 mas/yr

PM Declination

80.88 mas/yr

Galactic Cartesian (pc)

x = -0.969 · y = -0.143 · z = -0.201

Equatorial (J2000)

RA 188.39740° · Dec -11.62152°

Galactic ℓ, b

295.976° · 51.009°

Ecliptic λ, β

192.302° · -7.350°

HTM-20 index

1671657651

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