Key parameters at a glance

A radius of 4.00 Earth radii
A mass of 15.10 Earth masses
Surface gravity around 0.94 g
An orbital period of 44.505 days
Semi-major axis 0.2460 AU
Distance from Earth 55.18 light-years
Earth Similarity Index 0.545
Travel time at Voyager 1 speed 973,077 years

Context from the literature

HD 177565 b is an extrasolar planet orbiting the G-type main-sequence star HD 177565 55.3 light-years away from the Solar System.

Excerpted from Wikipedia · full article

HD 177565 b Planet Profile

Physical Specs

Radius

4.00 R⊕

Radius (Jupiter)

0.357 R♃

Mass

15.10 M⊕

Mass (Jupiter)

0.048 M♃

Density

1.30 g/cm³

Surface Gravity

0.94 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.545

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

#571of 574

top 99.3%

This planet

4.00R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-27 b 4.00 R⊕ Kepler-547 b 4.00 R⊕ Kepler-462 c 4.00 R⊕

Metric	Earth	HD 177565 b	Jupiter
Radius (R⊕)	1.00	4.00	11.21
Mass (M⊕)	1.00	15.10	317.83
Density (g/cm³)	5.51	1.30	1.33
Surface Gravity (g)	1.00	0.94	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	15.100 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 177565

HIP

HIP 93858

TIC

TIC 254147274

Gaia DR2

Gaia DR2 6718894388002453120

Gaia DR3

Gaia DR3 6718894388002453120

System

HD 177565

Percentile among Neptune-like cohort

Radius 4.000 R⊕ · percentile 0 / cohort 574

Mass 15.100 M⊕ · percentile 7 / cohort 574

Orbital period 44.51 d · percentile 68 / cohort 524

Distance 16.92 pc · percentile 4 / cohort 572

ESI 0.545 · percentile 99 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

44.505 days

Semi-major axis

0.2460 AU

Eccentricity

0.059

Inclination

— °

Year Length

A year here lasts approximately 44.51 Earth days (12.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2460 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.545

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Feng et al. 2017

Instrument

HARPS Spectrograph

Publication

2017-10

Observation locale

Ground

Discovery cohort

Planets confirmed in 2017 at La Silla Observatory (12 shown).

GJ 273 c · Rocky Terrestrial Ross 128 b · Rocky Terrestrial GJ 3138 b · Rocky Terrestrial GJ 3323 c · Super-Earth GJ 3323 b · Rocky Terrestrial GJ 273 b · Super-Earth GJ 3293 e · Super-Earth YZ Cet d · Rocky Terrestrial GJ 3138 c · Super-Earth YZ Cet c · Rocky Terrestrial GJ 3293 d · Sub-Neptune YZ Cet b · Rocky Terrestrial

Host System: HD 177565

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,627 K — cooler than the Sun (5,778 K)

Estimated Age

6.88 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.971 R☉

Stellar Mass

1.000 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

1.468 g/cm³

Systemic radial velocity

59.50 km/s

Rotational v·sin i

0.00 km/s

Activity index (log R'HK)

-4.850

Metallicity ratio

[M/H]

Distance

16.92 parsec

Light-years 55.18 ly

V-band magnitude

6.15 mag

Voyager-speed travel 973,077 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

59.080 mas

Total Proper Motion

412.213 mas/yr

PM Right Ascension

-187.64 mas/yr

PM Declination

-367.03 mas/yr

Galactic Cartesian (pc)

x = 0.227 · y = -0.757 · z = -0.613

Equatorial (J2000)

RA 286.71758° · Dec -37.81224°

Galactic ℓ, b

359.449° · -19.078°

Ecliptic λ, β

283.614° · -15.160°

HTM-20 index

353114496

Wikipedia → Image: Wikimedia Commons · 400Weir · CC BY-SA 4.0