NASA’s Kepler space telescope has seen a Jupiter look-alike in a new discovery, even though the instrument stopped operating four years ago.
An international team of astrophysicists using NASAs Kepler space telescope, which ceased operations in 2018, has discovered an exoplanet similar to Jupiter, located 17,000 light-years from Earth, making it the most distant exoplanet ever found by Kepler. That exoplanetofficially designated K2-2016-BLG-0005Lb, was seen in data captured by Kepler in 2016. Throughout its lifetime, Kepler observed over 2,700 now confirmed planets.
“Kepler was also able to observe continuously by weather or daylight, allowing us to determine the exact mass of the exoplanet and its orbital distance from its host star,” said Eamonn Kerins, an astronomer at the University of Manchester in the United Kingdom. said in a statement. “It’s basically Jupiter’s identical twin in terms of its mass and its position from its sun, which is about 60% of the mass of our own sun.”
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The team, led by David Specht, a Ph.D. students at the University of Manchester, utilized a phenomenon known as gravitational microlensing to spot the exoplanet. With this phenomenon, which was predicted by Einstein’s theory of relativityobjects in space can be seen and studied in more detail when the light from a background star is distorted and thus magnified by the gravity of a denser solid object.
Hoping to use the skewed light from a distant star to discover an exoplanet, the team used three months of observations that Kepler made of the stretch of sky where that planet lies.
“To see the effect at all, it requires almost perfect alignment between the foreground planetary system and a background star,” Kerins added in the same statement. “The chance of a background star being affected in this way by a planet is tens of thousands to hundreds of millions against one against. But there are hundreds of millions of stars towards the center of our galaxy. So Kepler just sat and watched them in three months. “
The team then worked with Iain McDonald, another astronomer at the University of Manchester, who developed a new search algorithm. Together, they were able to reveal five candidates in the data, one of which most clearly showed signs of an exoplanet. Other terrestrial observations of the same celestial body confirmed the same signals that Kepler saw of the possible exoplanet.
“The difference in vantage point between Kepler and observers here on Earth allowed us to triangulate where along our line of sight the planetary system is located,” Kerins said.
Aside from the thrill of discovering an exoplanet with an instrument that is no longer in operation, the team’s work is remarkable because Kepler was not designed to detect exoplanets using this phenomenon. However, it is important to note that Kepler’s mission was extended in 2016. In 2013, after two reaction wheel failures, it was suggested that Kepler be used for a K2 “second light” mission that would see the scope of discovering potentially habitable exoplanets. This extension was approved in 2014, and the mission was extended well past the scope’s expected end date until it finally ran out of fuel on October 30, 2018.
“Kepler was never designed to find planets using microlensing, so in many ways it’s amazing that it has,” Kerins said, adding that upcoming instruments such as NASA’s Nancy Grace Roman Space Telescope and the European Space Agency’s Euclid spacecraft mission could be able to use microlensing to study exoplanets and would be able to advance such research.
“Roman and Euclid, on the other hand, will be optimized for this kind of work. They will be able to complete the planet count started by Kepler,” Kerins said. “We will learn how typical the architecture of our own solar system is. The data will also allow us to test our ideas on how planets form. This is the start of a new exciting chapter in our search for other worlds.”
This discovery was described in a study submitted March 31 to preprint server ArXiv.org and has been submitted for publication in the Monthly Notices of the Royal Astronomical Society.