Key parameters at a glance

A radius of 5.11 Earth radii
A mass of 22.90 Earth masses
Surface gravity around 0.88 g
An orbital period of 123.010 days
Semi-major axis 0.4760 AU
Distance from Earth 27.73 light-years
Earth Similarity Index 0.470
Travel time at Voyager 1 speed 489,091 years

2 siblings around 61 Vir

61 Vir 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
61 Vir b	Sub-Neptune	2.11	5.10	4.215	—	2009
61 Vir c	Neptune-like	4.46	18.20	38.021	—	2009
61 Vir d this	Neptune-like	5.11	22.90	123.010	—	2009

61 Vir d Planet Profile

Physical Specs

Radius

5.11 R⊕

Radius (Jupiter)

0.456 R♃

Mass

22.90 M⊕

Mass (Jupiter)

0.072 M♃

Density

0.94 g/cm³

Surface Gravity

0.88 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.470

HZ Position Unknown

Controversial No

Discovery

Year 2009

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#366of 574

top 63.6%

This planet

5.11R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-1314 b 5.11 R⊕ HIP 48714 b 5.11 R⊕ Kepler-818 b 5.11 R⊕

Metric	Earth	61 Vir d	Jupiter
Radius (R⊕)	1.00	5.11	11.21
Mass (M⊕)	1.00	22.90	317.83
Density (g/cm³)	5.51	0.94	1.33
Surface Gravity (g)	1.00	0.88	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	22.900 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 115617

HIP

HIP 64924

TIC

TIC 422478973

Gaia DR2

Gaia DR2 3507879565090229888

Gaia DR3

Gaia DR3 3507879565090229888

System

61 Vir

Percentile among Neptune-like cohort

Radius 5.110 R⊕ · percentile 36 / cohort 574

Mass 22.900 M⊕ · percentile 37 / cohort 574

Orbital period 123.01 d · percentile 84 / cohort 524

Distance 8.50 pc · percentile 1 / cohort 572

ESI 0.470 · percentile 85 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

123.010 days

Semi-major axis

0.4760 AU

Eccentricity

0.350

Inclination

— °

Year Length

A year here lasts approximately 123.01 Earth days (33.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.4760 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

3.250 m/s

Transit mid-time (BJD)

2,455,245.8000

Long. of periastron (ω)

314.00°

Angular separation (arcsec)

56.00000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.470

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Vogt et al. 2010

Instrument

Multiple Instruments

Publication

2010-01

Observation locale

Ground

Discovery cohort

Planets confirmed in 2009 at Multiple Observatories (3 shown).

61 Vir b · Sub-Neptune 61 Vir c · Neptune-like HD 134987 c · Gas Giant

Host System: 61 Vir

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,577 K — cooler than the Sun (5,778 K)

Estimated Age

8.96 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.963 R☉

Stellar Mass

0.942 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.340 dex

Stellar density

1.449 g/cm³

Systemic radial velocity

-8.20 km/s

Rotational v·sin i

1.90 km/s

Activity index (log R'HK)

-5.040

Metallicity ratio

[Fe/H]

Distance

8.50 parsec

Light-years 27.73 ly

V-band magnitude

4.70 mag

Voyager-speed travel 489,091 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

117.573 mas

Total Proper Motion

1,508.842 mas/yr

PM Right Ascension

-1,070.81 mas/yr

PM Declination

-1,063.00 mas/yr

Galactic Cartesian (pc)

x = -0.894 · y = -0.318 · z = -0.314

Equatorial (J2000)

RA 199.59646° · Dec -18.31577°

Galactic ℓ, b

311.852° · 44.089°

Ecliptic λ, β

205.001° · -9.304°

HTM-20 index

224855835

Observation Record

Photometric series

RV measurements

Stellar spectra