The most distant exoplanet found by Kepler is … surprisingly familiar

An exoplanet has been found 17,000 light-years from Earth hiding in data collected by the now retired Kepler space telescope.

It’s the farthest world ever captured by the Planetary Observatory, twice the distance of the previous record. Surprisingly, the exoplanet is almost an exact twin of Jupiter – of similar mass, and orbits about the same distance as Jupiter’s distance from the Sun.

Named K2-2016-BLG-0005Lb, it represents the first exoplanet confirmed from 2016 data run that detected 27 possible objects using a technique called microgravity rather than Kepler’s initial discovery method. This discovery was submitted to Monthly Notices of the Royal Astronomical Societyand he Available on arXiv prepress server.

“Kepler was never designed to find planets using the micro-lens, so, in many ways, it’s amazing that it did,” Astronomer Eamonn Kearns said, from the University of Manchester.

The Kepler spacecraft has played a key role in opening up the field of extrasolar astronomy. Launched in 2009, it has spent nearly 10 years searching for planets outside the solar system, or exoplanets. During that time, his observations revealed more than 3,000 confirmed exoplanets, and 3,000 other candidates.

Its technology is deceptively simple and deceptively simple. Kepler stared at fields of stars, which were optimized to detect the faint, regular dips in starlight that would indicate an exoplanet in orbit around a star. This is called the transit method, and it’s good for finding nearby, larger exoplanets that orbit close to their stars.

Microlensing is a bit more complex, taking advantage of gravitational anomalies and shell alignment. The mass of an object like a planet creates a gravitational curvature of spacetime around it. If this planet passes in front of a star, the curved spacetime essentially acts as a magnifying glass that makes the star’s light shine dimly and for a short period.

A micro-gravitational lens is very good at finding exoplanets at a long distance from Earth, orbiting their stars at very large distances, down to very small masses of planets. The farthest exoplanet discovered so far has been captured by the micro-lens, an Earth-mass world 25,000 light-years away.

Because Kepler has been optimized to detect changes in starlight, a team of researchers led by the University of Manchester recently considered looking at Kepler data for microlensing events, from an observation window over several months in 2016. They identified 27 events, five of which were entirely new. , and has not yet been identified in data from ground-based telescopes.

“To see the effect at all would require a nearly perfect alignment between the foreground planetary system and the background star,” Kearns explained.

“The probability of a background star being affected in this way by a planet is tens to hundreds of millions to one. But there are hundreds of millions of stars toward the center of our galaxy. So Kepler sat and watched them for three months.”

One of the five events, K2-2016-BLG-0005Lb, looked promising for an exoplanet orbiting a star. So the team rummaged through data sets from five ground surveys that had been looking at the same patch of sky at the time Kepler was, to confirm their signals.

They found that Kepler noticed the signal a little earlier, and a little longer, than the five ground surveys. This combined data set allowed the team to determine that the exoplanet has a mass about 1.1 times the mass of Jupiter, and orbits its star at a circular distance of 4.4 astronomical units. The average distance between Jupiter and the Sun is 5.2 astronomical units.

“The difference in vantage point between Kepler and observers here on Earth allowed us to triangulate where the planetary system is located along our line of sight,” Kearns said.

“Kepler was also able to observe uninterruptedly by weather or daylight, which allowed us to accurately determine the mass of an exoplanet and the distance of its orbit from its host star. It is essentially the twin of Jupiter that is identical in terms of its mass and position from the Sun, which is about 60 percent from the mass of our Sun.

Although we do not currently have more data on the system, this discovery has implications for our search for extraterrestrial life. There is evidence to suggest that Jupiter may have played an instrumental role in the conditions that allowed the Earth to emerge and thrive on Earth; Finding isotopes of Jupiter orbiting distant stars could be a way to determine these terms.

The fact that Kepler, a tool not designed for a precision lens, was able to make this type of detection, bodes well for upcoming devices that will Be designed for precision lens. NASA’s Nancy Grace Roman Space Telescope is set to launch In the next five yearsyou will search for exact lens events, as well as ESA Euclidslated to be launched next year.

These discoveries could revolutionize our understanding of exoplanets.

“We will learn how the structure of our solar system is typical,” Kearns said. “The data will also allow us to test our ideas about how planets form. This is the start of an exciting new chapter in our search for other worlds.”

The search was submitted to Monthly Notices of the Royal Astronomical Society and available in arXiv.