Washington, June 2 :NASA has said that it will be studying two hot exoplanets classified as “super-Earths” that is situated 50 light years away and among them is planet ’55 Cancri e’, which is sort of like Earth but closer to star.
According to NASA, among the investigations planned for the first year are studies of two hot exoplanets classified as “super-Earths” for their size and rocky composition: the lava-covered 55 Cancri e and the airless LHS 3844 b.
The researchers will train James Webb Space Telescope’s high-precision spectrographs on these planets with a view to understanding the geologic diversity of planets across the galaxy, and the evolution of rocky planets like Earth.
55 Cancri e orbits less than 1.5 million miles from its Sun-like star (one twenty-fifth of the distance between Mercury and the Sun), completing one circuit in less than 18 hours. With surface temperatures far above the melting point of typical rock-forming minerals, the day side of the planet is thought to be covered in oceans of lava.
While it is considered that the hottest spot on the planet orbiting this close to their star would be the one facing the star at all times, the observations of 55 Cancri e from NASA’s Spitzer Space Telescope have suggested that the hottest region is offset from the part that faces the star most directly and the total amount of heat detected from the day side does vary.
“55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen. If it has an atmosphere, (Webb) has the sensitivity and wavelength range to detect it and determine what it is made of,” said Renyu Hu of NASA’s Jet Propulsion Laboratory in Southern California. He leads a team that will use Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) to capture the thermal emission spectrum of the day side of the planet.
Another intriguing possibility, however, is that 55 Cancri e is not tidally locked as it is rotating three times for every two orbits. As a result, the planet would have a day-night cycle.
Alexis Brandeker, a researcher from Stockholm University who leads another team studying the planet, said: “That could explain why the hottest part of the planet is shifted. Just like on Earth, it would take time for the surface to heat up. The hottest time of the day would be in the afternoon, not right at noon.”
