Key parameters at a glance

A radius of 3.06 Earth radii
A mass of 11.10 Earth masses
Surface gravity around 1.18 g
An orbital period of 21.403 days
Semi-major axis 0.1480 AU
Equilibrium temperature 620 K (346 °C)
Distance from Earth 159.73 light-years
Earth Similarity Index 0.383
Travel time at Voyager 1 speed 2,816,862 years

1 sibling around HD 63935

HD 63935 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
HD 63935 b	Sub-Neptune	2.92	10.50	9.059	825	2021
HD 63935 c this	Sub-Neptune	3.06	11.10	21.403	620	2021

HD 63935 c Planet Profile

Physical Specs

Radius

3.06 R⊕

Radius (Jupiter)

0.273 R♃

Mass

11.10 M⊕

Mass (Jupiter)

0.035 M♃

Density

2.11 g/cm³

Surface Gravity

1.18 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.383

HZ Position Inner

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#465of 1978

top 23.5%

This planet

3.06R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-351 b 3.06 R⊕ Kepler-151 b 3.06 R⊕ Kepler-760 b 3.06 R⊕

Metric	Earth	HD 63935 c	Jupiter
Radius (R⊕)	1.00	3.06	11.21
Mass (M⊕)	1.00	11.10	317.83
Density (g/cm³)	5.51	2.11	1.33
Surface Gravity (g)	1.00	1.18	2.53
Insolation (S⊕)	1.00	36.70	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	11.100 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

HD 63935

HIP

HIP 38374

TIC

TIC 453211454

Gaia DR2

Gaia DR2 3145754895088191744

Gaia DR3

Gaia DR3 3145754895088191744

System

HD 63935

Percentile among Sub-Neptune cohort

Radius 3.065 R⊕ · percentile 76 / cohort 1978

Mass 11.100 M⊕ · percentile 80 / cohort 1978

Orbital period 21.40 d · percentile 65 / cohort 1946

Distance 48.97 pc · percentile 12 / cohort 1975

ESI 0.383 · percentile 49 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

21.403 days

Semi-major axis

0.1480 AU

Eccentricity

0.000

Inclination

88.24 °

Year Length

A year here lasts approximately 21.40 Earth days (5.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1480 AU.

Transit Fingerprint

Depth

0.096 %

Duration

5.421 h

Impact parameter b

0.273

Rp / R★

0.029272

Transit midpoint (BJD)

2,458,504.1300

Photometric dip

Transit produces a flux drop of 961 ppm lasting ≈ 5.42 h.

Extended Orbital Architecture

Planet / star radius ratio

0.029272

Semi-major axis / stellar radius

33.060

Impact parameter (b)

0.273

RV semi-amplitude (K)

2.660 m/s

Transit mid-time (BJD)

2,458,504.1300

Long. of periastron (ω)

90.00°

Angular separation (arcsec)

3.02000

Eq. Temperature

620K

(346 °C)

Insolation (S⊕)

36.70

Earth = 1.00

Earth Similarity (ESI)

0.383

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

Scarsdale et al. 2021

Instrument

Multiple Instruments

Publication

2021-11

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at Multiple Observatories (12 shown).

L 98-59 e · Super-Earth GJ 393 b · Rocky Terrestrial HD 168009 b · Sub-Neptune HD 164922 e · Sub-Neptune HD 95735 c · Sub-Neptune HD 141004 b · Sub-Neptune HD 107148 c · Neptune-like TOI-178 f · Sub-Neptune TYC 0434-04538-1 b · Gas Giant HIP 56640 b · Gas Giant HD 137496 c · Gas Giant HD 156668 c · Neptune-like

Host System: HD 63935

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,513 K — cooler than the Sun (5,778 K)

Estimated Age

6.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.960 R☉

Stellar Mass

0.941 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.445 dex

Stellar density

1.486 g/cm³

Activity index (log R'HK)

-5.060

Metallicity ratio

[Fe/H]

Distance

48.97 parsec

Light-years 159.73 ly

V-band magnitude

8.58 mag

Voyager-speed travel 2,816,862 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

20.390 mas

Total Proper Motion

204.497 mas/yr

PM Right Ascension

-78.80 mas/yr

PM Declination

-188.71 mas/yr

Galactic Cartesian (pc)

x = -0.462 · y = 0.872 · z = 0.163

Equatorial (J2000)

RA 117.92464° · Dec 9.38524°

Galactic ℓ, b

211.236° · 17.613°

Ecliptic λ, β

118.114° · -11.370°

HTM-20 index

-407457889