Key parameters at a glance

A radius of 2.92 Earth radii
A mass of 11.24 Earth masses
Surface gravity around 1.32 g
An orbital period of 27.592 days
Semi-major axis 0.1721 AU
Equilibrium temperature 677 K (404 °C)
Distance from Earth 47.89 light-years
Earth Similarity Index 0.364
Travel time at Voyager 1 speed 844,474 years

2 siblings around HD 136352

HD 136352 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 136352 b	Super-Earth	1.66	4.72	11.578	905	2019
HD 136352 c this	Sub-Neptune	2.92	11.24	27.592	677	2019
HD 136352 d	Sub-Neptune	2.56	8.82	107.245	431	2019

HD 136352 c Planet Profile

Physical Specs

Radius

2.92 R⊕

Radius (Jupiter)

0.260 R♃

Mass

11.24 M⊕

Mass (Jupiter)

0.035 M♃

Density

2.50 g/cm³

Surface Gravity

1.32 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.364

HZ Position Inner

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

#606of 1978

top 30.6%

This planet

2.92R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 63935 b 2.92 R⊕ TOI-1203.01 2.92 R⊕ Kepler-153 b 2.92 R⊕

Metric	Earth	HD 136352 c	Jupiter
Radius (R⊕)	1.00	2.92	11.21
Mass (M⊕)	1.00	11.24	317.83
Density (g/cm³)	5.51	2.50	1.33
Surface Gravity (g)	1.00	1.32	2.53
Insolation (S⊕)	1.00	35.10	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	11.240 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	11.280 M⊕	Lower bound from radial-velocity fitting.
Computed mass	11.283 M⊕	Model-computed mass (e.g. from mass-radius relation).

Star Catalogue Identifiers

HD 136352

HIP

HIP 75181

TIC

TIC 136916387

Gaia DR2

Gaia DR2 5902750168276592256

Gaia DR3

Gaia DR3 5902750168276592256

System

HD 136352

Percentile among Sub-Neptune cohort

Radius 2.916 R⊕ · percentile 69 / cohort 1978

Mass 11.240 M⊕ · percentile 82 / cohort 1978

Orbital period 27.59 d · percentile 71 / cohort 1946

Distance 14.68 pc · percentile 3 / cohort 1975

ESI 0.364 · percentile 44 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

27.592 days

Semi-major axis

0.1721 AU

Eccentricity

0.000

Inclination

88.57 °

Year Length

A year here lasts approximately 27.59 Earth days (7.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1721 AU.

Transit Fingerprint

Depth

0.064 %

Duration

3.251 h

Impact parameter b

0.872

Rp / R★

0.025260

Transit midpoint (BJD)

2,458,954.4099

Photometric dip

Transit produces a flux drop of 638 ppm lasting ≈ 3.25 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025260

Semi-major axis / stellar radius

34.970

Impact parameter (b)

0.872

RV semi-amplitude (K)

2.610 m/s

Transit mid-time (BJD)

2,458,954.4099

Long. of periastron (ω)

-110.22°

Angular separation (arcsec)

11.70000

Eq. Temperature

677K

(404 °C)

Insolation (S⊕)

35.10

Earth = 1.00

Earth Similarity (ESI)

0.364

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

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

Udry et al. 2019

Instrument

HARPS Spectrograph

Publication

2019-02

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: HD 136352

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,664 K — cooler than the Sun (5,778 K)

Estimated Age

12.30 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.058 R☉

Stellar Mass

0.870 M☉

Metallicity [Fe/H]

-0.24

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

1.035 g/cm³

Systemic radial velocity

-69.00 km/s

Rotational v·sin i

1.00 km/s

Rotation period

23.80 days

Activity index (log R'HK)

-4.910

Metallicity ratio

[M/H]

Distance

14.68 parsec

Light-years 47.89 ly

V-band magnitude

5.65 mag

Voyager-speed travel 844,474 yr

Multi-band Host Photometry — 8 bands

Astrometric Data

Parallax

68.082 mas

Total Proper Motion

1,647.340 mas/yr

PM Right Ascension

-1,624.05 mas/yr

PM Declination

-276.02 mas/yr

Galactic Cartesian (pc)

x = -0.424 · y = -0.513 · z = -0.747

Equatorial (J2000)

RA 230.44011° · Dec -48.31882°

Galactic ℓ, b

327.071° · 7.381°

Ecliptic λ, β

241.104° · -28.770°

HTM-20 index

1294898941

Observation Record

Photometric series

RV measurements

Stellar spectra