Key parameters at a glance

A radius of 5.00 Earth radii
A mass of 22.10 Earth masses
Surface gravity around 0.88 g
An orbital period of 17.240 days
Semi-major axis 0.1400 AU
Distance from Earth 82.82 light-years
Earth Similarity Index 0.477
Travel time at Voyager 1 speed 1,460,579 years

Context from the literature

HD 16417 b is an extrasolar planet located approximately 83 light years away in the constellation of Fornax, orbiting the 6th magnitude G-type main sequence star HD 16417. This planet has a minimum mass only 7% that of Jupiter, making it a Neptune-mass planet. In addition to this, it orbits relatively close to the host star and suffers high temperature. It is the third planet discovered in the Fornax constellation on February 23, 2009. This planet was discovered by a method called the radial velocity method.

Excerpted from Wikipedia · full article

HD 16417 b Planet Profile

Physical Specs

Radius

5.00 R⊕

Radius (Jupiter)

0.446 R♃

Mass

22.10 M⊕

Mass (Jupiter)

0.070 M♃

Density

0.97 g/cm³

Surface Gravity

0.88 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.477

HZ Position Unknown

Controversial No

Discovery

Year 2008

Method Radial Velocity

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#382of 574

top 66.4%

This planet

5.00R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

CoRoT-24 c 5.00 R⊕ HD 47186 b 5.02 R⊕ KMT-2021-BLG-2294L b 5.02 R⊕

Metric	Earth	HD 16417 b	Jupiter
Radius (R⊕)	1.00	5.00	11.21
Mass (M⊕)	1.00	22.10	317.83
Density (g/cm³)	5.51	0.97	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)	22.100 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 16417

HIP

HIP 12186

TIC

TIC 122555698

Gaia DR2

Gaia DR2 5062172841616745856

Gaia DR3

Gaia DR3 5062172841616745856

System

HD 16417

Percentile among Neptune-like cohort

Radius 5.000 R⊕ · percentile 33 / cohort 574

Mass 22.100 M⊕ · percentile 35 / cohort 574

Orbital period 17.24 d · percentile 49 / cohort 524

Distance 25.39 pc · percentile 8 / cohort 572

ESI 0.477 · percentile 86 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

17.240 days

Semi-major axis

0.1400 AU

Eccentricity

0.200

Inclination

— °

Year Length

A year here lasts approximately 17.24 Earth days (4.7% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1400 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.477

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

O Toole et al. 2009

Instrument

UCLES Spectrograph

Publication

2009-06

Observation locale

Ground

Host System: HD 16417

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,841 K — hotter than the Sun (5,778 K)

Estimated Age

7.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.640 R☉

Stellar Mass

1.200 M☉

Metallicity [Fe/H]

0.06

Extended Stellar Properties

Surface gravity (log g)

4.160 dex

Stellar density

0.351 g/cm³

Systemic radial velocity

11.15 km/s

Rotational v·sin i

2.10 km/s

Metallicity ratio

[Fe/H]

Distance

25.39 parsec

Light-years 82.82 ly

V-band magnitude

5.78 mag

Voyager-speed travel 1,460,579 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

39.351 mas

Total Proper Motion

259.530 mas/yr

PM Right Ascension

-18.51 mas/yr

PM Declination

-258.87 mas/yr

Galactic Cartesian (pc)

x = 0.638 · y = 0.521 · z = -0.568

Equatorial (J2000)

RA 39.24410° · Dec -34.57909°

Galactic ℓ, b

237.696° · -66.238°

Ecliptic λ, β

21.571° · -46.711°

HTM-20 index

-1166820938

Observation Record

Photometric series

RV measurements

Archive notes

Wikipedia → Image: Wikimedia Commons · Planet Quest: New Worlds Atlas (Tweaks by Kevin Heider) · Public domain