NASA announces the sign of 5,000 exoplanets already confirmed by science – 03/22/2022

More than 5,000 exoplanets have been officially discovered so far, according to the NASA Exoplanet Archive on Monday (21). The announcement came after 65 new scientists were added to the official count for the US agency, whose file has been installed at the California Institute of Technology (California Institute of Technology).

Currently, the official number of exoplanets – planets outside our solar system – is 5,005. There are rocky Earth-like, super-gaseous planets known as “hot Jupiters” and also “little Neptune”, a shortened and potentially habitable version of Neptune that we find in our solar system. Stars, at least two different identification methods are used (transit method and gravitational effect).

According to the astronomer and principal investigator at NASA Exoplanet ArchiveMost exoplanets lie “in the little bubble around our solar system” because, here, they are “easy to find”.

“Of the 5,000 known exoplanets, 4,900 are located about 1,000 light-years away from us,” he explained to the official Caltech blog on Monday.

first planets

The first discovery was made in 1992, with two exoplanets located about 2,300 light-years from our solar system. Named after the Poltergeist and Phobetor, they had a mass of 4.3 and 3.9 times the mass of Earth and were found by astronomers Alexander Wolszchan and Dale Frail. At the time, these space planets were orbiting a dead pulsar-type star, which are neutron stars formed from the dead cores of other very massive stars.

Shortly after the discovery by Poltergeist and Phobetor, in 1994, another exoplanet was found orbiting the same star, which is now known as Lich. This world, called Draugr, was relatively smaller than its brethren, with a mass of about 0.02 times the mass of Earth.

Since the process of neutron star formation is a very aggressive process, involving continuous explosions of large dimensions, the discovery of these three worlds in the orbit of such a star drew attention to the fact that there could be many more exoplanets scattered around the world.

“If you can find planets orbiting a neutron star, [então] Planets should be basically everywhere [do universo]’,” Wolszchan explained to Official NASA Blog On this Monday.

Identification methods

To discover the first three exoplanets, a system that works only with stars of the pulsar type was used. That’s because the technique, which identifies planets from oscillations in the wavelength of stars, was based on millisecond pulses, which are only emitted by neutron stars.

Thus, to find exoplanets in galaxies with stars similar to our Sun, it will be necessary to search for other methodologies. This is where the transit method, first developed by NASA astronomer William Borucki, also came into play.

The transit method is widely used today and works by observing regular drops in the brightness of stars. That’s because these “drops,” when stationary, are actually the passage of an exoplanet between the host star (a star similar to the Sun) and our field of view.

In addition to the transit method, another technique astronomers use to identify exoplanets is the gravitational effect that these stars exert on their host stars. This methodology works similarly to transits, and is able to identify other worlds from oscillations in the wavelength of the stars being observed.

More than just different methods, new technologies used in space studies have also helped crowd the identification of exoplanets. To give you an idea, only with the Kepler telescope, which was launched into space in 2009, about 3,000 new scientists have been added to the official NASA archive.

From a terrestrial perspective, there is also the Harps spectrometer, which has been set up at the Paranal Observatory in Chile and has already identified about 150 exoplanets.

“It’s not just a number,” astronomer Jesse Christiansen said. “Everyone [desses exoplanetas] It’s a new world, a newly discovered planet.”

The expectation is that with the launch of new telescopes, such as James Webb, Released December 2021and Nancy Grace Roman, predicted that in 2027, the number of discovered exoplanets will increase.