Kepler-37 b: 0.31 Times Earth
Terrestrial around Kepler-37
It is 0.31 times Earth's radius, closest in size to Mars, and 0.8 times Earth's mass, at 140.00 g/cm3, denser than Earth. A year there lasts 13.37 days, on an orbit 4 times closer to its star than Mercury is to the Sun. Its equilibrium temperature is 718 K, hot enough to melt lead. The host star Kepler-37 runs at 5357 K with 0.79 times the Sun's mass.
140.0g/cm3: denser than iron at Earth surface pressure
Kepler-37 from the inside out
Orbit
/
Planet
Radius
0.31 Earth radii
Mass
0.8 Earth masses
Equilibrium temperature
718 K (measured)
One year
13.37 days
Orbit radius
0.1019 AU
Host star
Kepler-37 at 5357 K
Distance
208 light-years
Starlight blocked
0.001% at each transit
What you get from the shadow
The fraction of starlight blocked sets the radius against the star's.
Found by Kepler in 2013. Kepler watched a single field continuously, so it found the planets that come round often. A world with a long year simply never repeated within the mission.
Kepler-37 has 4 known planets. Planets in company tug on each other, and those tugs are measurable, which is how masses get pinned down without a wobble.
Size from the shadow, mass from elsewhere. Most transiting planets never get the second half, and without it composition stays a guess.
