The best hidden player in a cosmic game of hide-and-seek has just been given away by its own gravitational attraction. For the first time ever, scientists have identified an invisible alien planet by just noticing the gravitational attraction it exerts on another planet, which has been observed. The game was won by the NASA’s Kepler Space Telescope.
An artist's impression of Kepler 19c tugging stealthily at Kepler 19b, as the latter makes its transit across the host star. (Courtesy: David Augilar, Harvard-Smithsonian Center for Astrophysics)
An Alien World
Kepler detected one alien planet as it made a transit across the star it orbits. However, it was noticed that the transit started five minutes early and ended five minutes later than expected. This could only mean that another planetary body tugs on this planet speeding up or delaying its orbital speed. The observed planet has been named Kepler 19b and the unseen planet, Kepler 19c. This is the first time this technique – known as transit timing variation or TTV – has been used to figure out the existence of an exoplanet. The planetary system is 650 light years away in the constellation Lyra.
Sarah Ballard of Harvard-Smithsonian Center for Astrophysics explains it in naughty-next-door-kid jargon:
No comments:
Post a Comment