Exoplanet

K2-21 b

Orbiting K2-21

Overview

K2-21 b is an exoplanet orbiting the star K2-21, discovered in 2015 using the Transit method. It is a Super-Earth world.

Key Measurements

Radius

1.84

Earth radii

015 R⊕

Mass (est.)

4.30

Earth masses

0500 M⊕

Orbital Period

9.3

days

0.1d10,000d

Distance

83.6

parsecs

Nearby10,000 pc

Radius (Earth radii)

1.84

Mass (Earth masses)

4.30

Estimated

Equilibrium Temperature

Unknown

Parameter source: Dressing et al. 2017

Orbital Period

9.325+0.000−0.000days

Semi-Major Axis

0.0760+0.0020−0.0030au

Eccentricity

0.1000+0.1487−0.0847

Argument of Periastron

34.5+101.9−133.7deg

Distance from Earth

83.6 pc (~273 ly)

Spectral Type

Unknown

Temperature

4222 K

Mass (Solar)

0.68 M☉

Radius (Solar)

0.65 R☉

Luminosity

Unknown

Planets in System

2

Stars in System

1

Coordinates (RA, Dec)

340.3038°, -14.4893°

Discovery Method

Transit

Discovery Year

2015

Data Sources
NASA Exoplanet Archive

Source ID: K2-21 b

System Context

K2-21 b orbits K2-21 and was reported in 2015 and was detected with the Transit method.

Published measurements list a radius of 1.84 Earth radii, a mass of 4.3 Earth masses (estimated), and an orbital period of 9.33 days.

Catalog data places the system at about 83.6 parsecs from Earth and 2 known planets in the system.

Host star

Explore the stellar record for this system to compare temperature, spectral type, and known planets.

Open K2-21

More planets in this system

K2-21 c