Tel Aviv University researchers Prof. Shay Zucker, Head of the Porter School of the Environment and Earth Sciences, doctoral student Aviad Panhi from the Raymond and Beverly Sackler School of Physics & Astronomy, alongside Avraham Binnenfeld, Roy Gomel, and Sahar Shahaf, are among the scientists who in 2013 launched the spacecraft Gaia under the auspices of the European Space Agency (ESA), and are now collecting the amazing data the spacefaring observatory is sending back.
The study, conducted in cooperation with ESA and the research groups of the Gaia space telescope, was published in the scientific journal Astronomy & Astrophysics (The detection of transiting exoplanets by Gaia).
The spacecraft is designed for astrometry: measuring the positions, distances, and motions of stars with unprecedented precision. The mission aims to construct by far the largest and most precise 3D space catalog ever made, totaling approximately 1 billion astronomical objects, mainly stars, but also planets, comets, asteroids, and quasars, among others. It is expected to operate until 2025.
Most recently, Gaia has identified two new planets in remote solar systems, to be named hereafter Gaia-1b and Gaia-2b.
There are eight planets in our solar system (since Neil deGrasse Tyson demoted Pluto). But there are hundreds of thousands of other planets in our galaxy (the Milky Way, as long as deGrasse Tyson doesn’t change it) which contains untold numbers of solar systems. Those planets (the name means ‘wanderers’ in Greek) in their remote solar systems were first discovered in 1995 and have been the subject of astronomers’ research ever since.
Aviad Panhi explains: “The planets were discovered thanks to the fact that they partially hide their suns every time they complete an orbit, causing a cyclical drop in the intensity of the light reaching us from that distant sun. To confirm that they are in fact planets, we performed tracking measurements with the American Large Binocular Telescope, located in Arizona. This telescope is equipped with two giant mirrors, each with a diameter of 8.4 meters, making it one of the largest telescopes in the world today. This telescope makes it possible to track small fluctuations in a star’s movement which are caused by the presence of an orbiting planet.”
Prof. Shay Zucker has extensive experience in discovering planets, ever since his days as a student of the senior astronomer Prof. Tzevi Mazeh. He recalls: “The measurements we made with the telescope in the US confirmed that these were, in fact, two giant planets, similar in size to the planet Jupiter in our solar system, and located so close to their suns that they complete an orbit in less than four days, meaning that each Earth year is comparable to 90 years of that planet. The discovery of the two new planets was made in the wake of precise searches, using methods of artificial intelligence. We have published also 40 more candidates Gaia detected. The astronomical community will now have to try to corroborate their planetary nature as we did for the first two candidates.”
“The data continues to accumulate, and Gaia will likely discover many more planets with this method in the future,” says Prof. Zucker.
And what about the possibility of life on the surface of those remote new planets? Panhi is not too optimistic. “As we said, the new planets are very close to their suns, and therefore the temperature on them is extremely high about one thousand degrees Celsius, so there is zero chance of life developing there,” he says. “In the astronomy community, such a planet is called a ‘Hot Jupiter’ – ‘Jupiter’ because of its size, and ‘hot’ because of its proximity to its sun.”
But, probably betraying his years spent glued to Sci-Fi books, Panhi remains hopeful: “Even though there is no real chance of life on the planets we found, I’m convinced that there are countless others that do have life on them, and it’s reasonable to assume that in the next few years we will discover signs of organic molecules in the atmospheres of remote planets. Most likely we will not get to visit those distant worlds any time soon, but we’re just starting the journey, and it’s very exciting to be part of the search.”
Kakh oti la’manhig shel’kha (Heb. for Take me to your leader).
