An international group of astronomers using a 2-meter-class ground-based telescope has detected the shallow transit of a nearby exoplanet called 55 Cancri e.
A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body. The most notable solar transit is that of Venus, when during a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun.
Discovered in 2004, 55 Cancri e is one of five planets orbiting the Sun-like star 55 Cancri that is located 40 light-years from our planet yet visible to the naked eye in the constellation of Cancer.
The system consists of a G-type star and a smaller red dwarf, separated by over 1,000 AU (one thousand times the distance from the Earth to the Sun).
55 Cancri A has an apparent magnitude of 5.95, making it visible through binoculars. It is just visible to the naked eye under very dark skies. The red dwarf 55 Cancri B is of the 13th magnitude and only visible through a telescope.
55 Cancri e is a rushes around its star every 18 hours, in contrast to Earth’s 365 days. It is about 26 times closer than Mercury is to our sun, and locked so that one face is always blistering under the close heat of the star.
Previous observations of this exoplanet transit had to rely on space-borne telescopes, but now, astronomers led by Professor Ernst de Mooij from the University of Toronto have measured the passing of 55 Cancri e in front of its parent star using the 2.5-meter Nordic Optical Telescope in Spain.
This movement, a transit across a star, means that it blocks a tiny fraction of the starlight, dimming the star by 1/2000th (or 0.05 percent) for almost two hours. It is the first time a “super earth” has been seen from a ground telescope.
A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body. The most notable solar transit is that of Venus, when during a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun.
Discovered in 2004, 55 Cancri e is one of five planets orbiting the Sun-like star 55 Cancri that is located 40 light-years from our planet yet visible to the naked eye in the constellation of Cancer.
The system consists of a G-type star and a smaller red dwarf, separated by over 1,000 AU (one thousand times the distance from the Earth to the Sun).
55 Cancri A has an apparent magnitude of 5.95, making it visible through binoculars. It is just visible to the naked eye under very dark skies. The red dwarf 55 Cancri B is of the 13th magnitude and only visible through a telescope.
55 Cancri e is a rushes around its star every 18 hours, in contrast to Earth’s 365 days. It is about 26 times closer than Mercury is to our sun, and locked so that one face is always blistering under the close heat of the star.
Previous observations of this exoplanet transit had to rely on space-borne telescopes, but now, astronomers led by Professor Ernst de Mooij from the University of Toronto have measured the passing of 55 Cancri e in front of its parent star using the 2.5-meter Nordic Optical Telescope in Spain.
This movement, a transit across a star, means that it blocks a tiny fraction of the starlight, dimming the star by 1/2000th (or 0.05 percent) for almost two hours. It is the first time a “super earth” has been seen from a ground telescope.