Key parameters at a glance

A radius of 5.77 Earth radii
A mass of 51.10 Earth masses
Surface gravity around 1.53 g
An orbital period of 3.488 days
Semi-major axis 0.0474 AU
Equilibrium temperature 1,513 K (1240 °C)
Distance from Earth 3,026.67 light-years
Earth Similarity Index 0.120
Travel time at Voyager 1 speed 53,375,247 years

1 sibling around Kepler-101

Kepler-101 b 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
Kepler-101 b this	Neptune-like	5.77	51.10	3.488	1,513	2014
Kepler-101 c	Super-Earth	1.25	3.78	6.030	1,413	2014

Kepler-101 b Planet Profile

Physical Specs

Radius

5.77 R⊕

Radius (Jupiter)

0.510 R♃

Mass

51.10 M⊕

Mass (Jupiter)

0.160 M♃

Density

1.45 g/cm³

Surface Gravity

1.53 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.120

HZ Position Inner

Controversial No

Discovery

Year 2014

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#300of 574

top 52.1%

This planet

5.77R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-1520 b 5.77 R⊕ rho CrB c 5.78 R⊕ EPIC 211945201 b 5.76 R⊕

Metric	Earth	Kepler-101 b	Jupiter
Radius (R⊕)	1.00	5.77	11.21
Mass (M⊕)	1.00	51.10	317.83
Density (g/cm³)	5.51	1.45	1.33
Surface Gravity (g)	1.00	1.53	2.53
Insolation (S⊕)	1.00	1,240.33	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	51.100 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 48304653

Gaia DR2

Gaia DR2 2131709921047710336

Gaia DR3

Gaia DR3 2131709921047710336

System

Kepler-101

Percentile among Neptune-like cohort

Radius 5.770 R⊕ · percentile 48 / cohort 574

Mass 51.100 M⊕ · percentile 72 / cohort 574

Orbital period 3.49 d · percentile 8 / cohort 524

Distance 927.98 pc · percentile 72 / cohort 572

ESI 0.120 · percentile 5 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

3.488 days

Semi-major axis

0.0474 AU

Eccentricity

0.086

Inclination

85.82 °

Year Length

A year here lasts approximately 3.49 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0474 AU.

Transit Fingerprint

Depth

0.130 %

Duration

3.875 h

Impact parameter b

0.520

Rp / R★

0.034010

Transit midpoint (BJD)

2,455,088.7800

Photometric dip

Transit produces a flux drop of 1,299 ppm lasting ≈ 3.88 h.

Extended Orbital Architecture

Planet / star radius ratio

0.034010

Semi-major axis / stellar radius

6.550

Impact parameter (b)

0.520

RV semi-amplitude (K)

19.400 m/s

Transit mid-time (BJD)

2,455,088.7800

Long. of periastron (ω)

231.00°

Angular separation (arcsec)

0.05110

Eq. Temperature

1,513K

(1240 °C)

Insolation (S⊕)

1,240.33

Earth = 1.00

Earth Similarity (ESI)

0.120

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Detection Signatures

Transit photometry

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

Radial velocity

Stellar wobble has been measured spectroscopically.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-101

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,667 K — cooler than the Sun (5,778 K)

Estimated Age

5.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.560 R☉

Stellar Mass

1.170 M☉

Metallicity [Fe/H]

0.33

Extended Stellar Properties

Surface gravity (log g)

4.120 dex

Stellar density

0.437 g/cm³

Systemic radial velocity

-77.71 km/s

Rotational v·sin i

2.60 km/s

Metallicity ratio

[Fe/H]

Distance

927.98 parsec

Light-years 3,026.67 ly

V-band magnitude

13.70 mag

Voyager-speed travel 53,375,247 yr

Multi-band Host Photometry — 15 bands

Astrometric Data

Parallax

1.049 mas

Total Proper Motion

6.936 mas/yr

PM Right Ascension

0.71 mas/yr

PM Declination

6.90 mas/yr

Galactic Cartesian (pc)

x = 0.152 · y = -0.647 · z = 0.747

Equatorial (J2000)

RA 283.25551° · Dec 48.35525°

Galactic ℓ, b

78.047° · 19.673°

Ecliptic λ, β

297.219° · 70.544°

HTM-20 index

1917243441