Key parameters at a glance

A radius of 1.74 Earth radii
A mass of 3.68 Earth masses
Surface gravity around 1.22 g
An orbital period of 5.668 days
Semi-major axis 0.0677 AU
Equilibrium temperature 1,336 K (1063 °C)
Distance from Earth 3,943.75 light-years
Earth Similarity Index 0.206
Travel time at Voyager 1 speed 69,547,990 years

4 siblings around Kepler-33

Kepler-33 b 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
Kepler-33 b this	Super-Earth	1.74	3.68	5.668	1,336	2011
Kepler-33 c	Sub-Neptune	3.20	0.39	13.176	1,009	2011
Kepler-33 d	Neptune-like	5.35	3.91	21.776	853	2011
Kepler-33 e	Neptune-like	4.02	5.57	31.784	752	2011
Kepler-33 f	Neptune-like	4.46	9.60	41.029	691	2011

Kepler-33 b Planet Profile

Physical Specs

Radius

1.74 R⊕

Radius (Jupiter)

0.155 R♃

Mass

3.68 M⊕

Mass (Jupiter)

0.012 M♃

Density

3.84 g/cm³

Surface Gravity

1.22 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.206

HZ Position Inner

Controversial No

Discovery

Year 2011

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#344of 1176

top 29.2%

This planet

1.74R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-918 b 1.74 R⊕ Kepler-260 c 1.74 R⊕ TOI-1266 d 1.74 R⊕

Metric	Earth	Kepler-33 b	Jupiter
Radius (R⊕)	1.00	1.74	11.21
Mass (M⊕)	1.00	3.68	317.83
Density (g/cm³)	5.51	3.84	1.33
Surface Gravity (g)	1.00	1.22	2.53
Insolation (S⊕)	1.00	744.01	0.037

Star Catalogue Identifiers

TIC

TIC 158935283

Gaia DR2

Gaia DR2 2127355923723254272

Gaia DR3

Gaia DR3 2127355923723254272

System

Kepler-33

Percentile among Super-Earth cohort

Radius 1.740 R⊕ · percentile 70 / cohort 1176

Mass 3.680 M⊕ · percentile 64 / cohort 1176

Orbital period 5.67 d · percentile 44 / cohort 1164

Distance 1,209.16 pc · percentile 89 / cohort 1171

ESI 0.206 · percentile 14 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

5.668 days

Semi-major axis

0.0677 AU

Eccentricity

0.000

Inclination

86.39 °

Year Length

A year here lasts approximately 5.67 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0677 AU.

Transit Fingerprint

Depth

0.009 %

Duration

4.880 h

Impact parameter b

0.500

Rp / R★

0.008770

Transit midpoint (BJD)

2,454,964.8981

Photometric dip

Transit produces a flux drop of 87 ppm lasting ≈ 4.88 h.

Extended Orbital Architecture

Planet / star radius ratio

0.008770

Semi-major axis / stellar radius

7.870

Impact parameter (b)

0.500

Transit mid-time (BJD)

2,454,964.8981

Angular separation (arcsec)

0.05600

Eq. Temperature

1,336K

(1063 °C)

Insolation (S⊕)

744.01

Earth = 1.00

Earth Similarity (ESI)

0.206

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.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Lissauer et al. 2012

Instrument

Kepler CCD Array

Publication

2012-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2011 at Kepler (12 shown).

Kepler-22 b · Sub-Neptune Kepler-20 d · Sub-Neptune Kepler-26 c · Sub-Neptune Kepler-19 c · Sub-Neptune Kepler-26 b · Sub-Neptune Kepler-28 c · Super-Earth Kepler-10 c · Sub-Neptune Kepler-20 f · Rocky Terrestrial Kepler-42 d · Rocky Terrestrial Kepler-16 b · Neptune-like Kepler-28 b · Super-Earth Kepler-34 b · Neptune-like

Host System: Kepler-33

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,904 K — hotter than the Sun (5,778 K)

Estimated Age

4.27 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.820 R☉

Stellar Mass

1.291 M☉

Metallicity [Fe/H]

0.03

Extended Stellar Properties

Surface gravity (log g)

4.027 dex

Stellar density

0.300 g/cm³

Systemic radial velocity

14.09 km/s

Rotational v·sin i

3.40 km/s

Metallicity ratio

[Fe/H]

Distance

1,209.16 parsec

Light-years 3,943.75 ly

V-band magnitude

14.10 mag

Voyager-speed travel 69,547,990 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.798 mas

Total Proper Motion

13.130 mas/yr

PM Right Ascension

-1.11 mas/yr

PM Declination

-13.08 mas/yr

Galactic Cartesian (pc)

x = 0.227 · y = -0.656 · z = 0.719

Equatorial (J2000)

RA 289.07753° · Dec 46.00517°

Galactic ℓ, b

77.263° · 15.134°

Ecliptic λ, β

305.681° · 67.096°

HTM-20 index

1983176106