Kepler 1658 b - first exoplanet confirmed by NASA as real world

  

Ten years after it was launched, the first exoplanet candidate spotted by NASA's Kepler space telescope has finally been confirmed as a real world, scientists say. 

The exoplanet designated as Kepler-1658 b is a massive hot Jupiter sized planet that whips around its native star every 3.85 days, said researchers from University of Hawaii in US. 

From the surface of the planet, its star would appear 60 times larger as compared to that of our Sun as seen from earth, they said. 

Kepler space telescope has discovered thousands of exoplanets since it was launched ten years ago in 2009. To do so, it uses the transit method - small fluctuations in the star's brightness when a planet crosses it. 

However, other phenomena can also mimic the transit, such as a group of asteroids or dust and gases etc. Hence, further analysis is required to confirm them as genuine planets, as said in a study published in the Astronomical Journal. 

Despite being the very first candidate to be discovered by Kepler in 2011, the Kepler-1658 b had a rocky road to confirmation.

The initial estimates about the size of its host star was incorrect, so the size of both the star as well as the planet were vastly underestimated, researchers said. 

It was later set aside as a false positive when the numbers did not quite make sense for the effects seen on the star for a body of that size, they said. 

"Our new analysis, which uses stellar sound waves observed in the Kepler data to characterize the host star, demonstrated that the star is infact three times larger than previously thought", said Ashley Chontos - a graduate student in the University of Hawaii. 

"This in turn means that the planet Kepler-1658 b is also three times larger, revealing that it is actually a hot Jupiter-like planet", Chontos further added in his statement. 

With this refined analysis, everything pointed to the object truly being a planet, but confirmation from new observations was still required. 

Kepler-1658 star is 50 percent more massive and three times larger than our Sun, researchers said. 

The newly confirmed planet orbits at a distance of only twice the diameter of its star - making it one of the closest planets around a more evolved star - one that resembles a future version of our Sun. 

Standing on the planet, the star would appear 60 times larger than our sun, as seen from earth, said the researchers.

Planets orbiting evolved stars like Kepler-1658 are rare, and the reasons for this absence is poorly understood, they said. 

The extreme nature of the Kepler-1658 system allows the astronomers to put new constraints on the complex physical interactions that can cause planets to spiral into their host stars. 

The insights gained from Kepler-1658 b suggest that this process happens slower than previously thought, and therefore may not be the primary reason for the lack of planets around more evolved stars. 

Image credits: NASA/JPL-Caltech