55 Cancri e (55 Cnc e)
is a super-Earth of about 8 Earth masses,
orbiting a K-type star, but close to the star
with an orbital period of about 18 hours
(but was initially thought to have a period
of 2.8 days).
Its determined density is based on estimates
of the host star's mass and radius
along with data from observed transits
and the star's radial velocity, yielding
a radius of roughly 2 Earth radii and
a density slightly (5%-10%) more than Earth's.
Given its proximity to the star, the temperature
of the star-facing side has been calculated
to be more than 3000 K.
Characteristics: