Over 300 new exoplanets identified from Kepler data
Image credit: UNIVERSITY OF CAMBRIDGE
Astronomers have used a new planet detection algorithm to identify 366 new exoplanets, including one planetary system that comprises a star and at least two gas giant planets.
The term ‘exoplanets’ is used to describe planets outside of our own solar system. The number of exoplanets that have been identified by astronomers totals fewer than 5,000 in all, so the identification of hundreds of new ones is a significant advance.
The team from University Of California – Los Angeles (UCLA) believe that studying such a large new group of bodies could improve understanding of how planets form and orbits evolve, and it could provide new insights about how unusual our solar system is.
“Discovering hundreds of new exoplanets is a significant accomplishment by itself, but what sets this work apart is how it will illuminate features of the exoplanet population as a whole,” said Erik Petigura, a UCLA astronomy professor and co-author of the research.
One challenge in identifying new planets is that reductions in stellar brightness may originate from the instrument or from an alternative astrophysical source that mimics a planetary signature. Teasing out which ones are which requires extra investigation, which traditionally has been extremely time-consuming and can only be accomplished through visual inspection.
The new algorithm is able to separate which signals indicate planets and which are merely noise.
“I have no doubt they will sharpen our understanding of the physical processes by which planets form and evolve,” said Erik Petigura, co-author of the research.
The exoplanets were identified using data from Nasa’s Kepler Space Telescope which unfortunately came to an unexpected end in 2013 when a mechanical failure left the spacecraft unable to precisely point at the patch of sky it had been observing for years.
But astronomers repurposed the telescope for a new mission known as K2, whose objective is to identify exoplanets near distant stars. Data from K2 is helping scientists understand how stars’ location in the galaxy influences what kind of planets are able to form around them.
For the new study, the researchers used the new software to analyse the entire dataset from K2 — about 500 terabytes of data encompassing more than 800 million images of stars — to create a “catalogue” that will soon be incorporated into Nasa’s master exoplanet archive.
In addition to the 366 new planets the researchers identified, the catalogue lists 381 other planets that had been previously identified.
The researchers believe their findings could be a significant step toward helping astronomers understand which types of stars are most likely to have planets orbiting them and what that indicates about the building blocks needed for successful planet formation.
The discovery of a planetary system with two gas giant planets was also significant because it’s rare to find gas giants — like Saturn in our own solar system — as close to their host star as they were in this case.
Last year, another team of researchers identified two dozen exoplanets that may be better than the Earth at supporting life because they were deemed to be slightly warmer and wetter.
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