An exoplanet is a planet outside the solar system.
The planet, named 55 Cancri e, is 60 percent larger than Earth and eight times as massive. Twice as dense as Earth - almost as dense as lead - it is the densest solid planet known, according to the latest findings.
A team of astronomers from the Massachusetts Institute of Technology (MIT), the University of British Columbia (UBC), the Harvard-Smithsonian Centre for Astrophysics and the University of California at Santa Cruz (UCSC) were involved in research.
The research, based on observations from Canada's Microvariability and Oscillations of Stars (MOST) space telescope, was released online at arXiv.org, scheduled for publication in The Astrophysical Journal Letters.
MOST is a Canadian space agency mission.
Approximately 40 light years from Earth, 55 Cancri e orbits a star called 55 Cancri A so closely that its year is less than 18 hours long.
"You could set dates on this world by your wrist watch, not a calendar," says UBC astronomer Jaymie Matthews, according to an UBC statement.
The temperature on the planet's surface could be as high as 2,700 degrees Celsius.
"Because of the infernal heat, it's unlikely that 55 Cancri e has an atmosphere," says lead author Josh Winn of MIT. "So this is not the type of place where exobiologists would look for life."
While the planet is not visible, even through a telescope, its host star, 55 Cancri A, can be observed with the naked eye for the next two months on a clear dark night.
