Key parameters at a glance

A radius of 0.76 Earth radii
A mass of 1.30 Earth masses
Surface gravity around 2.28 g
An orbital period of 21.302 days
Semi-major axis 0.1390 AU
Equilibrium temperature 615 K (342 °C)
Distance from Earth 208.48 light-years
Earth Similarity Index 0.432
Travel time at Voyager 1 speed 3,676,566 years

Context from the literature

Kepler-37c is an exoplanet discovered by the Kepler space telescope in February 2013. With an orbital period of 21 days, it is located 209 light-years away, in the constellation Lyra.

Excerpted from Wikipedia · full article

3 siblings around Kepler-37

Kepler-37 c 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
Kepler-37 b	Rocky Terrestrial	0.31	0.79	13.367	718	2013
Kepler-37 c this	Rocky Terrestrial	0.76	1.30	21.302	615	2013
Kepler-37 d	Sub-Neptune	2.03	2.00	39.792	499	2013
Kepler-37 e	Rocky Terrestrial	0.37	8.10	51.196	401	2014

Kepler-37 c Planet Profile

Physical Specs

Radius

0.76 R⊕

Radius (Jupiter)

0.067 R♃

Mass

1.30 M⊕

Mass (Jupiter)

0.004 M♃

Density

15.00 g/cm³

Surface Gravity

2.28 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.432

HZ Position Inner

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#505of 570

top 88.4%

This planet

0.76R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

TRAPPIST-1 h 0.76 R⊕ Kepler-1864 b 0.75 R⊕ K2-413 b 0.76 R⊕

Metric	Earth	Kepler-37 c	Jupiter
Radius (R⊕)	1.00	0.76	11.21
Mass (M⊕)	1.00	1.30	317.83
Density (g/cm³)	5.51	15.00	1.33
Surface Gravity (g)	1.00	2.28	2.53
Insolation (S⊕)	1.00	23.90	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.300 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 164652245

Gaia DR2

Gaia DR2 2106674071344722688

Gaia DR3

Gaia DR3 2106674071344722688

System

Kepler-37

Percentile among Rocky Terrestrial cohort

Radius 0.755 R⊕ · percentile 11 / cohort 570

Mass 1.300 M⊕ · percentile 50 / cohort 570

Orbital period 21.30 d · percentile 93 / cohort 567

Distance 63.92 pc · percentile 19 / cohort 566

ESI 0.432 · percentile 64 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

21.302 days

Semi-major axis

0.1390 AU

Eccentricity

0.099

Inclination

89.07 °

Year Length

A year here lasts approximately 21.30 Earth days (5.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1390 AU.

Transit Fingerprint

Depth

0.009 %

Duration

3.813 h

Impact parameter b

0.430

Rp / R★

0.009440

Transit midpoint (BJD)

2,455,024.8400

Photometric dip

Transit produces a flux drop of 85 ppm lasting ≈ 3.81 h.

Extended Orbital Architecture

Planet / star radius ratio

0.009440

Semi-major axis / stellar radius

42.180

Impact parameter (b)

0.430

RV semi-amplitude (K)

0.340 m/s

Transit mid-time (BJD)

2,455,024.8400

Angular separation (arcsec)

2.17000

Eq. Temperature

615K

(342 °C)

Insolation (S⊕)

23.90

Earth = 1.00

Earth Similarity (ESI)

0.432

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Barclay et al. 2013

Instrument

Kepler CCD Array

Publication

2013-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: Kepler-37

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,357 K — cooler than the Sun (5,778 K)

Estimated Age

7.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.789 R☉

Stellar Mass

0.790 M☉

Metallicity [Fe/H]

-0.36

Extended Stellar Properties

Surface gravity (log g)

4.567 dex

Stellar density

2.460 g/cm³

Systemic radial velocity

-30.10 km/s

Rotational v·sin i

1.10 km/s

Metallicity ratio

[Fe/H]

Distance

63.92 parsec

Light-years 208.48 ly

V-band magnitude

9.77 mag

Voyager-speed travel 3,676,566 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

15.616 mas

Total Proper Motion

77.677 mas/yr

PM Right Ascension

-60.52 mas/yr

PM Declination

48.69 mas/yr

Galactic Cartesian (pc)

x = 0.173 · y = -0.692 · z = 0.701

Equatorial (J2000)

RA 284.05925° · Dec 44.51837°

Galactic ℓ, b

74.437° · 17.844°

Ecliptic λ, β

295.961° · 66.695°

HTM-20 index

842412176

Wikipedia →