Graphical representation of an Exoplanet (Click Image to Download)
For the first time, an international team of astronomers has used a ground-based telescope to detect and observe the transit of a planet in front of a Sun-like star outside of our own solar system.
Until now, only space-based telescopes were capable of detecting the transits of exoplanets as they passed by bright stars.
Distortions caused by the atmosphere , the same phenomenon that makes stars look like they’re twinkling, makes it difficult for astronomers to observe transiting planets around bright stars from telescopes based on Earth.
In September, 2013, Japanese astronomers, using the ground-based Subaru telescope were able to observe the transit of super-Earth, GJ 1214b , but this exoplanet orbits a much dimmer star, known as a red dwarf.
According to team leader, Dr. Ernst de Mooij of Queen’s University Belfast in Northern Ireland, 55 Cancri e, was measured to have a diameter of about 26,000 km, which is twice that of Earth, but with eight times its mass.
This artist’s conception shows the super-Earth 55 Cancri e (right) compared to the Earth (left). (NASA/JPL) (Click Image to Download)
The most recent achievement involves a super-sized Earth-like planet in a binary star system more than 40-light years away. Called 55 Cancri e , the planet orbits its primary star 55 Cancri A , in the constellation Cancer. The solar system’s secondary star, 55 Cancri B, is a red dwarf star which is located about 159,321,732,615 km from the primary star.
Scientists say that while the primary star can be seen with the naked eye, it takes ideal conditions such as a clear and moonless night.
An artist’s concept of exoplanet 55 Cancri e as it closely orbits its star 55 Cancri A (NASA/JPL-Caltech) (Click Image to Download)
Previous studies have found that the planet makes one complete orbit around its sun in about 18 hours and that since its daytime temperature can reach nearly 1,700° Celsius, 55 Cancri e is not at all hospitable to life.
A number of small, extra-solar planets are expected to be discovered in the next ten years as new observational space missions — including NASA’s Transiting Exoplanet Survey Satellite (TESS) , and the European Space Agency’s Planetary Transits and Oscillations of Stars (PLATO) –are launched.
Both PLATO – set to go in 2014 and TESS, scheduled for a 2017 launch – will look for transiting Earth-like planets circling nearby bright stars.
Source : blogs.voanews.com
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