Month: April 2020

Kepler-1649 c

Kepler-1649 c is an Earth-sized exoplanet discovered by re-analyzing data from the Kepler space telescope. Its size is around 1.06 times the radius of the earth, and the mass is 1.21 times the mass, estimated by ExoKyoto. The host star, Kepler-1649, is an M5V type red-dwarf with a surface temperature of 3240K. Its radius is estimated to be about 25% of the sun and its mass is about 21.9%. The exoplanet orbits the red dwarf, at around 0.0855 astronomical units (1,280,000 km) which takes about 19.5 days. The estimated black body temperature of Kepler-1649 c is 245.39K assuming an albedo of 0.3, which is almost the same as the earth (255K). If the atmospheric pressure and components are similar to the earth, it is very probable that its environment also resembles the Earth

However, the exoplanet is most likely tidally locked, due to it revolving around a red dwarf star. Also, the light seen from the surface of the planet would be significantly different from sunlight on Earth, composed of about 90% infrared rays and only 8.87% visible light component (according to Exo Kyoto).

Ultraviolet radiation, including extreme ultraviolet radiation, is estimated to be about 0.17%, which requires more detailed observation.

Kepler-1649 c’s orbit and habitable zone according to Kopparapu et al.2013.
Size comparison according to ExoKyoto

Kepler-1649’s estimated spectra using the ExoKyoto spectrum module

For more detailed information on Kepler-1649 please visit to the following database page


WASP-76b is an exoplanet that revolves around the star WASP-76 about 640 light years away in the Pisces constellation.

The star WASP-76 has an apparent magnitude of 9.5, an absolute magnitude of 4.1, and is a spectral F7 type star with a surface temperature of 6250K.

The star has a mass about 1.5 times that of the sun and a radius about 1.7 times that of the sun.

WASP-76b is the only planet orbiting WASP-76 and it is classified as a hot jupiter.

The exoplanet was discovered by the transit method in 2013.

Its mass is about 0.92 times that of Jupiter, but the powerful radiation from the main star expands the atmosphere and the radius is about 1.83 times that of Jupiter, making it a low-density planet.

The largest radius of its orbit is about 0.033 AU (5 million km) and its orbit lasts around 1.8 days.

Its temperature is 2700K on the day-side and 1800K on the night-side; it is tidally locked. 

In 2020, observations at the Paranal Observatory with the Very Large Telescope (VLT) revealed that the day-side atmosphere was rich in iron vapor.

A strong wind blows on the surface because the temperature difference between the day-side and the night-side is close to 1000K. The wind and the rotation carry iron vapor from the day-side to the night-side, which causes cooling. It is thought that this causes condensation, which becomes rain.