Key parameters at a glance

A radius of 1.87 Earth radii
A mass of 3.41 Earth masses
Surface gravity around 0.98 g
An orbital period of 29.797 days
Semi-major axis 0.1646 AU
Equilibrium temperature 467 K (194 °C)
Distance from Earth 127.31 light-years
Earth Similarity Index 0.580
Travel time at Voyager 1 speed 2,245,148 years
Almost certainly tidally locked to its host star given the close orbit

4 siblings around HD 23472

HD 23472 c shares its host star with 4 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 23472 d	Rocky Terrestrial	0.75	0.55	3.977	909	2022
HD 23472 e	Rocky Terrestrial	0.82	0.72	7.908	723	2022
HD 23472 f	Rocky Terrestrial	1.14	0.77	12.162	630	2022
HD 23472 b	Sub-Neptune	2.00	8.32	17.667	543	2019
HD 23472 c this	Super-Earth	1.87	3.41	29.797	467	2019

HD 23472 c Planet Profile

Physical Specs

Radius

1.87 R⊕

Radius (Jupiter)

0.167 R♃

Mass

3.41 M⊕

Mass (Jupiter)

0.011 M♃

Density

3.10 g/cm³

Surface Gravity

0.98 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.580

HZ Position Inner

Controversial No

Discovery

Year 2019

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#169of 1176

top 14.3%

This planet

1.87R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-824 b 1.87 R⊕ Kepler-299 e 1.87 R⊕ EPIC 201238110 b 1.87 R⊕

Metric	Earth	HD 23472 c	Jupiter
Radius (R⊕)	1.00	1.87	11.21
Mass (M⊕)	1.00	3.41	317.83
Density (g/cm³)	5.51	3.10	1.33
Surface Gravity (g)	1.00	0.98	2.53
Insolation (S⊕)	1.00	7.96	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	3.410 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

HD 23472

HIP

HIP 17264

TIC

TIC 425997655

Gaia DR2

Gaia DR2 4674216245427964416

Gaia DR3

Gaia DR3 4674216245427964416

System

HD 23472

Percentile among Super-Earth cohort

Radius 1.870 R⊕ · percentile 85 / cohort 1176

Mass 3.410 M⊕ · percentile 55 / cohort 1176

Orbital period 29.80 d · percentile 91 / cohort 1164

Distance 39.03 pc · percentile 8 / cohort 1171

ESI 0.580 · percentile 80 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

29.797 days

Semi-major axis

0.1646 AU

Eccentricity

0.063

Inclination

89.10 °

Year Length

A year here lasts approximately 29.80 Earth days (8.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1646 AU.

Transit Fingerprint

Depth

0.061 %

Duration

2.940 h

Impact parameter b

0.785

Rp / R★

0.024300

Transit midpoint (BJD)

2,458,370.1037

Photometric dip

Transit produces a flux drop of 615 ppm lasting ≈ 2.94 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024300

Semi-major axis / stellar radius

50.200

Impact parameter (b)

0.785

RV semi-amplitude (K)

0.920 m/s

Transit mid-time (BJD)

2,458,370.1037

Long. of periastron (ω)

2.00°

Angular separation (arcsec)

4.22000

Eq. Temperature

467K

(194 °C)

Insolation (S⊕)

7.96

Earth = 1.00

Earth Similarity (ESI)

0.580

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.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Trifonov et al. 2019

Instrument

TESS CCD Array

Publication

2019-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2019 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

LP 791-18 c · Sub-Neptune LTT 1445 A b · Super-Earth TOI-270 d · Sub-Neptune L 98-59 d · Super-Earth GJ 357 b · Rocky Terrestrial GJ 143 b · Sub-Neptune L 98-59 c · Super-Earth LP 791-18 b · Rocky Terrestrial TOI-270 c · Sub-Neptune HD 23472 b · Sub-Neptune TOI-270 b · Super-Earth L 98-59 b · Rocky Terrestrial

Host System: HD 23472

Spectral Class

K-type orange

Effective Temperature

4,684 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.710 R☉

Stellar Mass

0.670 M☉

Metallicity [Fe/H]

-0.20

Extended Stellar Properties

Surface gravity (log g)

4.530 dex

Stellar density

2.707 g/cm³

Systemic radial velocity

34.55 km/s

Rotational v·sin i

1.45 km/s

Rotation period

40.10 days

Activity index (log R'HK)

-4.997

Metallicity ratio

[Fe/H]

Distance

39.03 parsec

Light-years 127.31 ly

V-band magnitude

9.73 mag

Voyager-speed travel 2,245,148 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

25.590 mas

Total Proper Motion

111.577 mas/yr

PM Right Ascension

-102.57 mas/yr

PM Declination

-43.92 mas/yr

Galactic Cartesian (pc)

x = 0.259 · y = 0.377 · z = -0.889

Equatorial (J2000)

RA 55.45903° · Dec -62.76727°

Galactic ℓ, b

277.027° · -44.848°

Ecliptic λ, β

358.263° · -74.955°

HTM-20 index

730030629

Similar Worlds

Kepler-1032 b

Super-Earth · K-type orange

Radius 1.87 R⊕ · 2,195.1 ly

HD 156668 b

Super-Earth · K-type orange

Radius 1.87 R⊕ · 79.4 ly

TOI-2322 c

Super-Earth · K-type orange

Radius 1.87 R⊕ · 195.2 ly

Kepler-1221 b

Super-Earth · K-type orange

Radius 1.88 R⊕ · 2,979.9 ly

Kepler-440 b

Super-Earth · K-type orange

Radius 1.86 R⊕ · 981.8 ly

Kepler-48 b

Super-Earth · K-type orange

Radius 1.88 R⊕ · 1,000.4 ly

Explore Related Categories

Super-Earth Planets Transit Discoveries Transiting Exoplanet Survey Satellite (TESS) Mission K-type orange Hosts