An exoplanet has been discovered 17,000 light-years from Earth hidden in data collected by the now retired Kepler space telescope.
It’s the farthest place in the world captured by the Planetary Hunting Observatory, twice the distance of the previous record. Surprisingly, the exoplanet is roughly the exact twin of Jupiter – of similar mass, and orbiting about the same distance as Jupiter’s distance from the Sun.
Named K2-2016-BLG-0005Lb, it represents the first confirmed exoplanet from the 2016 data set that revealed 27 possible objects using a technique called microgravity rather than Kepler’s initial discovery method. The discovery was submitted to Monthly Notices of the Royal Astronomical SocietyIt is available on the arXiv demo server.
“Kepler was never designed to find planets using microlensing, so it’s surprising in many ways that it did,” said astronomer Eamonn Kerns of the University of Manchester.
The Kepler spacecraft played a fundamental role in opening up the field of exoplanet astronomy. It was launched in 2009 and has spent nearly 10 years hunting for exoplanets or exoplanets. Meanwhile, his observations have revealed more than 3,000 confirmed exoplanets and 3,000 other candidates.
His technique is ingeniously simple and deceptive. Kepler looked at star fields, optimized to detect the faint, regular dips in starlight that indicate an exoplanet orbiting a star. It’s called the transit method, and it’s good for finding nearby larger exoplanets that orbit close to their stars.
Precision lenses are a little trickier, taking advantage of gravitational anomalies and random 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 space-time essentially acts as a magnifying glass, illuminating the light from the star very weakly and for a short time.
A microgravitational lens is very effective for finding exoplanets at long distances from Earth, and orbiting their stars at fairly large distances, down to very small planetary masses. The farthest exoplanet discovered so far has been captured by Microlensing, an Earth-mass world 25,000 light-years away.
Because Kepler has been optimized for detecting 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, you need a near-perfect alignment between the foreground planetary system and the background star,” Kerns explained.
“The probability of a background star being affected in this way by a planet ranges from 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 her for three months.”
One of the five events, K2-2016-BLG-0005Lb, looked promising for an exoplanet orbiting a star. So the team looked for data sets from five ground surveys that looked at the same piece of sky at the time Kepler was, to confirm their signals.
They found that Kepler noticed the signal a little earlier and for a little longer than the five readings of the Earth. This combined data set allowed the team to determine that the exoplanet is about 1.1 times the mass of Jupiter, orbiting its star at a circular distance of 4.4 AU. The average distance from Jupiter to the Sun is 5.2 astronomical units.
“The difference in perspective 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 monitor weather or daylight without interruption, which allowed us to accurately determine the mass of an exoplanet and the orbital distance of its host star. It is essentially the twin of Jupiter that is identical in mass and position relative to its Sun, and it accounts for about 60% of 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 been beneficial in the conditions that allowed the Earth to emerge and thrive on Earth; Finding the analogues of Jupiter orbiting distant stars can be one way to determine these terms.
The fact that Kepler, an instrument not designed for a precision lens, was able to perform this type of detection bodes well for future devices that will Be designed for precision lens. The scheduled launch of NASA’s Nancy Grace Roman Space Telescope in the next five years will look for micro-lens events, just like the European Space Agency’s Euclid, which is scheduled to launch next year.
These discoveries could revolutionize our understanding of exoplanets.
“We will learn how typical the structure of our solar system is,” Kerns said. “The data will also allow us to test our ideas about how planets form. It is the beginning of an exciting new chapter in our search for other worlds.”
The search was submitted to Monthly Notices of the Royal Astronomical Society It is available on arXiv.