Confirmed Exoplanet Discovered 2009

HD 125612 c

A neptune-like orbiting the g-type yellow (sun-like) HD 125612, located approximately 187.9 light-years from Earth.

Key parameters at a glance

  • A radius of 4.07 Earth radii
  • A mass of 15.57 Earth masses
  • Surface gravity around 0.94 g
  • An orbital period of 4.155 days
  • Semi-major axis 0.0510 AU
  • Distance from Earth 187.93 light-years
  • Earth Similarity Index 0.539
  • Travel time at Voyager 1 speed 3,314,205 years

Context from the literature

HD 125612 c is an extrasolar planet which orbits the G-type main sequence star HD 125612, located approximately 188 light years away in the constellation Virgo. The discovery of this planet was announced by the HARPS team on October 19, 2009, together with 31 other planets, including HD 125612 d.

Excerpted from Wikipedia · full article

2 siblings around HD 125612

HD 125612 c 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 125612 c this Neptune-like 4.07 15.57 4.155 2009
HD 125612 b Gas Giant 13.20 945.22 557.700 2007
HD 125612 d Gas Giant 12.70 2,281.37 2,822.727 2009

HD 125612 c Planet Profile

Physical Specs

Radius
4.07 R⊕
Radius (Jupiter)
0.363 R♃
Mass
15.57 M⊕
Mass (Jupiter)
0.049 M♃
Density
1.27 g/cm³
Surface Gravity
0.94 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.539
HZ Position Unknown
Controversial No

Discovery

Year 2009
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#551of 574

top 95.8%

This planet

4.07R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth HD 125612 c Jupiter
Radius (R⊕)1.004.0711.21
Mass (M⊕)1.0015.57317.83
Density (g/cm³)5.511.271.33
Surface Gravity (g)1.000.942.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Minimum mass (M sin i) 15.574 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 125612

HIP

HIP 70123

TIC

TIC 347909637

Gaia DR2

Gaia DR2 6296703260330865536

Gaia DR3

Gaia DR3 6296703260330865536

System

HD 125612

Percentile among Neptune-like cohort

Radius 4.070 R⊕ · percentile 4 / cohort 574
Mass 15.574 M⊕ · percentile 10 / cohort 574
Orbital period 4.15 d · percentile 14 / cohort 524
Distance 57.62 pc · percentile 17 / cohort 572
ESI 0.539 · percentile 98 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
4.155 days
Semi-major axis
0.0510 AU
Eccentricity
0.149
Inclination
°

Year Length

A year here lasts approximately 4.15 Earth days (1.1% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0510 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.539

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Lo Curto et al. 2010

Instrument

HARPS Spectrograph

Publication

2010-03

Observation locale

Ground

Host System: HD 125612

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,900 K — hotter than the Sun (5,778 K)

Estimated Age

1.77 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.070 R☉

Stellar Mass

1.050 M☉

Metallicity [Fe/H]

0.23

Extended Stellar Properties

Surface gravity (log g)

4.450 dex

Stellar density

1.017 g/cm³

Systemic radial velocity

-18.40 km/s

Rotational v·sin i

2.10 km/s

Rotation period

10.50 days

Metallicity ratio

[Fe/H]

Distance
57.62 parsec
Light-years 187.93 ly
V-band magnitude
8.31 mag
Voyager-speed travel 3,314,205 yr

Multi-band Host Photometry — 11 bands

6.88.98.93B8.31V8.16Gaia7.73TESS7.18J6.95H6.84K6.81W16.82W26.84W36.82W4

Astrometric Data

Parallax

17.326 mas

Total Proper Motion

90.389 mas/yr

PM Right Ascension

-60.26 mas/yr

PM Declination

-67.37 mas/yr

Galactic Cartesian (pc)

x = -0.779 · y = -0.550 · z = -0.300

Equatorial (J2000)

RA 215.22272° · Dec -17.48181°

Galactic ℓ, b

331.389° · 40.395°

Ecliptic λ, β

218.695° · -3.256°

HTM-20 index

1449905202

Observation Record

Photometric series

1

RV measurements

1

Stellar spectra

2

Archive notes

5

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