Key parameters at a glance

A radius of 1.61 Earth radii
A mass of 16.17 Earth masses
Surface gravity around 6.24 g
An orbital period of 46.859 days
Semi-major axis 0.2370 AU
Equilibrium temperature 411 K (137 °C)
Distance from Earth 21.30 light-years
Earth Similarity Index 0.560
Travel time at Voyager 1 speed 375,663 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

HD 219134 d, also known as HR 8832 d, is an exoplanet orbiting around the K-type star HD 219134 in the constellation of Cassiopeia. It has a minimum mass over 16 times that of Earth, indicating that it is likely a Hot Neptune. The exoplanet was initially detected by the instrument HARPS-N of the Italian Telescopio Nazionale Galileo via the radial velocity method. Unlike HD 219134 b and HD 219134 c it was not observed by the Spitzer Space Telescope and thus its radius and density are unknown. Only a minimum possible mass can be given.

Excerpted from Wikipedia · full article

3 siblings around HD 219134

HD 219134 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 219134 b	Super-Earth	1.60	4.74	3.093	1,015	2015
HD 219134 c	Super-Earth	1.51	4.36	6.765	782	2015
HD 219134 d this	Super-Earth	1.61	16.17	46.859	411	2015
HD 219134 h	Gas Giant	12.70	108.06	2,247.000	—	2015

HD 219134 d Planet Profile

Physical Specs

Radius

1.61 R⊕

Radius (Jupiter)

0.144 R♃

Mass

16.17 M⊕

Mass (Jupiter)

0.051 M♃

Density

— g/cm³

Surface Gravity

6.24 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.560

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Radial Velocity

Facility Roque de los Muchachos Observatory

Telescope 3.58 m Telescopio Nazionale Galileo

Size rank in cohort

Rank by radius

#550of 1176

top 46.7%

This planet

1.61R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-62 e 1.61 R⊕ Kepler-149 c 1.61 R⊕ Kepler-140 b 1.61 R⊕

Metric	Earth	HD 219134 d	Jupiter
Radius (R⊕)	1.00	1.61	11.21
Mass (M⊕)	1.00	16.17	317.83
Density (g/cm³)	5.51	—	1.33
Surface Gravity (g)	1.00	6.24	2.53
Insolation (S⊕)	1.00	4.72	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	16.170 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	16.400 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 219134

HIP

HIP 114622

TIC

TIC 283722336

Gaia DR2

Gaia DR2 2009481748875806976

Gaia DR3

Gaia DR3 2009481748875806976

System

HD 219134

Percentile among Super-Earth cohort

Radius 1.610 R⊕ · percentile 52 / cohort 1176

Mass 16.170 M⊕ · percentile 97 / cohort 1176

Orbital period 46.86 d · percentile 95 / cohort 1164

Distance 6.53 pc · percentile 1 / cohort 1171

ESI 0.560 · percentile 78 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

46.859 days

Semi-major axis

0.2370 AU

Eccentricity

0.138

Inclination

— °

Year Length

A year here lasts approximately 46.86 Earth days (12.8% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.2370 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

3.340 m/s

Transit mid-time (BJD)

2,455,207.9300

Long. of periastron (ω)

173.00°

Angular separation (arcsec)

36.30000

Eq. Temperature

411K

(137 °C)

Insolation (S⊕)

4.72

Earth = 1.00

Earth Similarity (ESI)

0.560

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Motalebi et al. 2015

Instrument

HARPS-N Spectrograph

Publication

2015-12

Observation locale

Ground

Discovery cohort

Planets confirmed in 2015 at Roque de los Muchachos Observatory (3 shown).

HD 219134 c · Super-Earth HD 219134 b · Super-Earth HD 219134 h · Gas Giant

Host System: HD 219134

Spectral Class

K-type orange

Effective Temperature

4,699 K — cooler than the Sun (5,778 K)

Estimated Age

11.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.778 R☉

Stellar Mass

0.810 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.567 dex

Stellar density

2.438 g/cm³

Systemic radial velocity

-18.42 km/s

Rotational v·sin i

0.40 km/s

Metallicity ratio

[Fe/H]

Distance

6.53 parsec

Light-years 21.30 ly

V-band magnitude

5.57 mag

Voyager-speed travel 375,663 yr

Multi-band Host Photometry — 7 bands

Astrometric Data

Parallax

153.081 mas

Total Proper Motion

2,095.381 mas/yr

PM Right Ascension

2,074.52 mas/yr

PM Declination

294.94 mas/yr

Galactic Cartesian (pc)

x = 0.531 · y = -0.110 · z = 0.840

Equatorial (J2000)

RA 348.33720° · Dec 57.16963°

Galactic ℓ, b

109.907° · -3.201°

Ecliptic λ, β

23.752° · 54.542°

HTM-20 index

331589954

Observation Record

Photometric series

RV measurements

Stellar spectra

Archive notes

Wikipedia →

Similar Worlds

Kepler-62 e

Super-Earth · K-type orange

Radius 1.61 R⊕ · 981.3 ly

Kepler-1048 b

Super-Earth · K-type orange

Radius 1.61 R⊕ · 1,813.4 ly

Kepler-1749 b

Super-Earth · K-type orange

Radius 1.61 R⊕ · 874.8 ly

HD 219134 b

Super-Earth · K-type orange

Radius 1.60 R⊕ · 21.3 ly

Kepler-1702 b

Super-Earth · K-type orange

Radius 1.60 R⊕ · 2,795.6 ly

EPIC 212499991 b

Super-Earth · K-type orange

Radius 1.60 R⊕ · 924.0 ly

Explore Related Categories

Super-Earth Planets Radial Velocity Discoveries Roque de los Muchachos Observatory Mission K-type orange Hosts