Key parameters at a glance

A radius of 3.23 Earth radii
A mass of 10.49 Earth masses
Surface gravity around 1.01 g
An orbital period of 9.639 days
Semi-major axis 0.0952 AU
Equilibrium temperature 900 K (627 °C)
Distance from Earth 50.87 light-years
Earth Similarity Index 0.253
Travel time at Voyager 1 speed 897,165 years

3 siblings around HD 160691

HD 160691 d shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 160691 d this	Sub-Neptune	3.23	10.49	9.639	900	2004
HD 160691 e	Unclassified	—	2,224.80	307.900	—	2006
HD 160691 b	Unclassified	—	1,366.66	645.000	—	2000
HD 160691 c	Unclassified	—	1,398.44	3,947.000	—	2004

HD 160691 d Planet Profile

Physical Specs

Radius

3.23 R⊕

Radius (Jupiter)

0.288 R♃

Mass

10.49 M⊕

Mass (Jupiter)

0.033 M♃

Density

1.71 g/cm³

Surface Gravity

1.01 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.253

HZ Position Unknown

Controversial No

Discovery

Year 2004

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#325of 1978

top 16.4%

This planet

3.23R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 12235 b 3.23 R⊕ GJ 3138 d 3.23 R⊕ Kepler-1636 b 3.23 R⊕

Metric	Earth	HD 160691 d	Jupiter
Radius (R⊕)	1.00	3.23	11.21
Mass (M⊕)	1.00	10.49	317.83
Density (g/cm³)	5.51	1.71	1.33
Surface Gravity (g)	1.00	1.01	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	10.490 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 160691

HIP

HIP 86796

TIC

TIC 362661163

Gaia DR2

Gaia DR2 5945941905576552064

Gaia DR3

Gaia DR3 5945941905576552064

System

HD 160691

Percentile among Sub-Neptune cohort

Radius 3.230 R⊕ · percentile 83 / cohort 1978

Mass 10.490 M⊕ · percentile 76 / cohort 1978

Orbital period 9.64 d · percentile 32 / cohort 1946

Distance 15.60 pc · percentile 3 / cohort 1975

ESI 0.253 · percentile 17 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

9.639 days

Semi-major axis

0.0952 AU

Eccentricity

0.000

Inclination

— °

Year Length

A year here lasts approximately 9.64 Earth days (2.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0952 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

2.940 m/s

Transit mid-time (BJD)

2,455,205.1500

Long. of periastron (ω)

197.00°

Angular separation (arcsec)

6.10000

Eq. Temperature

900K

(627 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.253

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Santos et al. 2004

Instrument

HARPS Spectrograph

Publication

2004-10

Observation locale

Ground

Discovery cohort

Planets confirmed in 2004 at La Silla Observatory (3 shown).

HD 41004 A b · Gas Giant HD 202206 c · Gas Giant HD 330075 b · Gas Giant

Host System: HD 160691

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,773 K — cooler than the Sun (5,778 K)

Estimated Age

5.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.330 R☉

Stellar Mass

1.130 M☉

Metallicity [Fe/H]

0.28

Extended Stellar Properties

Surface gravity (log g)

4.200 dex

Stellar density

0.555 g/cm³

Systemic radial velocity

-9.29 km/s

Rotational v·sin i

3.10 km/s

Activity index (log R'HK)

-5.020

Metallicity ratio

[Fe/H]

Distance

15.60 parsec

Light-years 50.87 ly

V-band magnitude

5.12 mag

Voyager-speed travel 897,165 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

64.082 mas

Total Proper Motion

191.532 mas/yr

PM Right Ascension

-15.31 mas/yr

PM Declination

-190.92 mas/yr

Galactic Cartesian (pc)

x = -0.043 · y = -0.616 · z = -0.786

Equatorial (J2000)

RA 266.03616° · Dec -51.83488°

Galactic ℓ, b

340.060° · -11.499°

Ecliptic λ, β

267.212° · -28.434°

HTM-20 index

1868394459

Observation Record

Photometric series

RV measurements

Archive notes