There are another 2,423 Kepler telescopes yet to be confirmed. This meant that the sizes of both the star and the planet were significantly underestimated and thus scientists were unable to explain certain characteristics of the proposed system. Kepler-1658b, orbiting with a period of just 3.8 days, was the first exoplanet candidate discovered by Kepler almost 10 years ago. Instituto de Astrofísica de Canarias.
Planets orbiting evolved stars similar to Kepler-1658 are rare, and the reason for this absence is poorly understood.
The star has 50 per cent more mass than our sun, and it's three times larger. From the planet's surface, its star would appear 60 times larger in diameter than Earth's sun appears from its surface.
Hot Jupiters were common discoveries during the early days of exoplanet hunting because they were easy to find, but they represent only about 1% of known exoplanets now.
Despite being the very first planet candidate discovered by Kepler in 2011, Kepler-1658 b had a rocky road to confirmation.
The candidate, known as KOI (Kepler Object of Interest) 4.01, was originally pegged as a possible Neptune-size planet orbiting a star a smidge bigger than our sun. When the numbers didn't add up, scientists thought they had made a mistake and said the data didn't point to a planet.
Kepler 1658b bounced back and forth between being a planetary candidate and being false positive until its collected data was refined with computer software.
"Our new analysis, which uses stellar sound waves observed in the Kepler data to characterize the star, demonstrated that the star [and the planet are] in fact three times larger than previously thought", she told NASA.
"This in turn means that the planet is three times larger, revealing that Kepler-1658 b is actually a hot Jupiter-like planet", Chontos said in a statement.
"We were able to extract this astroseismic signal from the data using two different techniques, and in so doing pin-down the size of the star with great precision", said University of Birmingham's Dr. Guy Davies.
After Chontos and her team's initial analysis, the presence of a planet was confirmed using follow-up observations conducted by astronomer Dave Latham from Harvard University.
"Kepler-1658 is a ideal example of why a better understanding of host stars of exoplanets is so important", Chontos said. The newly confirmed planet orbits at a distance of only twice the star's diameter, making it one of the closest-in planets around a more evolved star - one that resembles a future version of our Sun.
The extreme nature of the Kepler-1658 system allows astronomers to place new constraints on the complex physical interactions that can cause planets to spiral into their host stars.
"Confirming that Kepler's first exoplanet candidate really is a planet is a wonderful legacy result, which brings things full-circle, now that Kepler has finished taking data", Bill Chaplin, an author of the study from the University of Birmingham in the United Kingdom, said in a statement.