Key parameters at a glance

A radius of 2.02 Earth radii
A mass of 4.72 Earth masses
Surface gravity around 1.16 g
An orbital period of 3.142 days
Semi-major axis 0.0447 AU
Equilibrium temperature 1,632 K (1359 °C)
Distance from Earth 203.97 light-years
Earth Similarity Index 0.155
Travel time at Voyager 1 speed 3,597,082 years

3 siblings around DMPP-1

DMPP-1 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
DMPP-1 d this	Sub-Neptune	2.02	4.72	3.142	1,632	2019
DMPP-1 e	Super-Earth	1.86	4.13	5.516	1,314	2019
DMPP-1 c	Sub-Neptune	3.31	10.94	10.030	1,239	2019
DMPP-1 b	Neptune-like	4.26	16.80	17.812	877	2019

DMPP-1 d Planet Profile

Physical Specs

Radius

2.02 R⊕

Radius (Jupiter)

0.180 R♃

Mass

4.72 M⊕

Mass (Jupiter)

0.015 M♃

Density

3.15 g/cm³

Surface Gravity

1.16 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.155

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#1927of 1978

top 97.4%

This planet

2.02R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1422 b 2.02 R⊕ Kepler-343 c 2.02 R⊕ Kepler-833 b 2.02 R⊕

Metric	Earth	DMPP-1 d	Jupiter
Radius (R⊕)	1.00	2.02	11.21
Mass (M⊕)	1.00	4.72	317.83
Density (g/cm³)	5.51	3.15	1.33
Surface Gravity (g)	1.00	1.16	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	4.720 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 38677

HIP

HIP 27305

TIC

TIC 66560666

Gaia DR2

Gaia DR2 3011005587574818432

Gaia DR3

Gaia DR3 3011005587574818432

System

DMPP-1

Percentile among Sub-Neptune cohort

Radius 2.020 R⊕ · percentile 2 / cohort 1978

Mass 4.720 M⊕ · percentile 4 / cohort 1978

Orbital period 3.14 d · percentile 5 / cohort 1946

Distance 62.54 pc · percentile 14 / cohort 1975

ESI 0.155 · percentile 3 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

3.142 days

Semi-major axis

0.0447 AU

Eccentricity

0.360

Inclination

— °

Year Length

A year here lasts approximately 3.14 Earth days (0.9% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0447 AU.

Eq. Temperature

1,632K

(1359 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.155

0 = alien, 1 = Earth-identical

Insufficient insolation data — the dayside is scorched.

Discovery Paper

Primary reference

Staab et al. 2020

Instrument

HARPS Spectrograph

Publication

2019-12

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at La Silla Observatory (12 shown).

HD 20781 b · Rocky Terrestrial HD 20781 c · Sub-Neptune HD 21693 b · Sub-Neptune HD 45184 c · Sub-Neptune HD 134060 b · Sub-Neptune HD 31527 b · Sub-Neptune HD 20781 d · Sub-Neptune HD 20003 b · Sub-Neptune HD 31527 d · Sub-Neptune HD 45184 b · Sub-Neptune HD 51608 b · Sub-Neptune HD 136352 d · Sub-Neptune

Host System: DMPP-1

Spectral Class

F-type yellow-white

Effective Temperature

6,196 K — hotter than the Sun (5,778 K)

Estimated Age

2.01 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.260 R☉

Stellar Mass

1.210 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.410 dex

Stellar density

0.813 g/cm³

Systemic radial velocity

28.66 km/s

Rotational v·sin i

3.41 km/s

Distance

62.54 parsec

Light-years 203.97 ly

V-band magnitude

7.98 mag

Voyager-speed travel 3,597,082 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

15.961 mas

Total Proper Motion

21.447 mas/yr

PM Right Ascension

2.73 mas/yr

PM Declination

-21.27 mas/yr

Galactic Cartesian (pc)

x = 0.055 · y = 0.981 · z = -0.184

Equatorial (J2000)

RA 86.77612° · Dec -10.63032°

Galactic ℓ, b

215.359° · -19.053°

Ecliptic λ, β

86.172° · -34.027°

HTM-20 index

-561627319