Kepler-37d
Super-Earth orbiting Kepler-37
From Wikipedia, the free encyclopedia
Kepler-37d is an exoplanet discovered by the Kepler space telescope in February 2013.[4] It is located 209 light years away,[5] in the constellation Lyra.[4] With an orbital period of 39.8 days,[3] it is the largest of the three known planets orbiting its parent star Kepler-37.[6]
| Discovery[1] | |
|---|---|
| Discovery site | Kepler space telescope |
| Discovery date | 2013 |
| Transit | |
| Orbital characteristics[2] | |
| 0.2109±0.0030 AU | |
| Eccentricity | <0.10 |
| 39.7922622(65) d | |
| Inclination | 89.335°+0.043° −0.047° |
| Star | Kepler-37 |
| Physical characteristics[2] | |
| 2.030+0.030 −0.039 R🜨 | |
| Mass | 5.4±1.4 M🜨[3] or <2.0 M🜨[2] |
Mean density | 4.29+0.52 −0.74 g/cm3[3] or <1.3 g/cm3[2] |
| Temperature | 499±7 K (226 °C; 439 °F, equilibrium) |
A 2021 study detected Kepler-37d via radial velocity, finding a mass of about 5.4 M🜨,[3] but a 2023 study instead found an upper limit on its mass of only 2 M🜨.[2] In either case, it is not a rocky planet, but a low-density planet rich in volatiles.
In 2015, a grant was approved to further expand the Sagan Planet Walk by installing a Kepler-37d station on the Moon 384,500 kilometers (238,900 mi) away.[7][8]
Host star
The planet orbits a (G-type) star similar to the Sun, named Kepler-37, orbited by a total of four planets. The star has a mass of 0.80 M☉ and a radius of 0.79 R☉. It has a temperature of 5417 K and is 5.66 billion years old. In comparison, the Sun is 4.6 billion years old,[9] and has a temperature of 5778 K.[10]
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 9.71. Therefore, it is too dim to be seen with the naked eye.