It took William Herschel a lifetime to discover Uranus back in 1781. Cosmologist James Peebles and astronomers Michel Mayor and Didier Queloz took nearly 7 years discovering and confirming the existence of an exoplanet in the year 1995, for which they were awarded for the Nobel Prize for physics in 2019. But a 17-year-old just outperformed them. Wolf Cuckier joined NASA’s Goddard Space Flight Center as a summer intern under Planet Hunters TESS citizen science project. He was assigned to examine the variation in the brightness of distant stars in search for the existence of exoplanets. And guess what!! He did it in just 3 days into his internship. This was the quickest discovery of an exoplanet. What he discovered was a dip in the brightness of a Double Star system. The resulting comprehension confirms the presence of a circumbinary planet, a world orbiting two stars.
The planet, called TOI 1338 b, is around 6.9 times larger than Earth, or between the sizes of Neptune and Saturn. It lies in a system 1,300 light-years away in the constellation Pictor. The stars in the system make an eclipsing binary, which occurs when the stellar companions circle each other in our plane of view. One is about 10% more massive than our Sun, while the other is cooler, dimmer and only one-third the Sun’s mass. TOI 1338 b’s transits are irregular, between every 93 and 95 days, and vary in depth and duration thanks to the orbital motion of its stars. TESS only sees the transits crossing the larger star — the transits of the smaller star are too faint to detect. Its orbit is stable for at least the next 10 million years. The orbit’s angle to us, however, changes enough that the planet transit will cease after November 2023 and resume eight years later. (Source: NASA’s Goddard Space Flight Center)
This remarkable discovery is a part of NASA’s Transiting Exoplanet Survey Satellite (TESS) mission which started in early 2019 with a launch aboard SpaceX Falcon 9 on April 18, 2019. The mission objective is to search for planets outside of our solar system (technically called exoplanets), that can support life or have earth-like features. The mission uses transit photometry as a tool to determine the existence of such planets. In this method, the periodic variation in the brightness of the light coming from a distant star is measured to determine the presence of an exoplanet around it. The photometric signature is used to find the size, distance, orbit and relative position of the star with that of its orbiting planet.
The TESS mission has been planned to conduct this extraterrestrial search in a very systematic way. According to NASA, TESS will survey the entire sky over the course of two years by breaking it up into 26 different sectors, each by 24 degrees by 96 degrees across. The powerful cameras on the spacecraft will stare at each sector for at least 27 days, looking at the brightest stars at a two-minute cadence. From Earth, the moon occupies half a degree, which is less than 1/9,000th the size of the TESS tiles. TESS will create a catalog of about thousands of exoplanets and upon compiling the data, a ground-based analysis will be conducted in order to confirm the existence of these exoplanets.
The ground-based telescopes will collaborate with other ground-based telescopes to measure the masses of the planets. Using the known planet size, orbit and mass, TESS and ground-based follow-up will be able to determine the planets’ compositions. This will reveal whether the planets are rocky (like Earth), gas giants (like Jupiter) or something even more unusual. Additional follow-up with ground- and space-based missions, including NASA’s James Webb Space Telescope, will also allow astronomers to study the atmospheres of many of these planets.
The quest for the search of extraterrestrial life has been the hottest interest of modern astronomy lovers. And this discovery by Wolf has triggered worldwide interest in ‘Exoplanet Hunting’. However, the relevance of this discovery or this very objective remains a debatable topic among scholars given the present scenario. Despite being able to find life on such a remote planet, humanity does not justify the sustenance of life on earth itself.
Read this article in the Scientia Magazine. Click here to go to the page.