NASA’s Kepler Space Telescope in its K2 mission recently collected data about 197 primary planet candidates that were evaluated by an international team of astronomers that confirmed 104 of them outside our solar system.
In the discovery, all authors present 197 planet candidates that were discovered using NASA K2 mission data with the results of an intensive program of photometric analyses, high-resolution imaging, stellar spectroscopy, and statistical validation. But from all 197 planets, 30 were false positives, 104 were validated, and 63 remain as candidates. Among the Earth telescopes used to find the exoplanets are the North Gemini telescope and the W.N. Keck Observatory in Hawaii, the Large Binocular Telescope operated by the University of Arizona, and the Automated Planet Finder of the University of California Observatories.
All new planets orbit the M dwarf star K2-72, which is found 181 light-years away in the direction of the Aquarius constellation. A dwarf star is an average star, although it could be smaller. The M dwarf star K2-72 compared to our sun is less than half the size and less bright. Scientists say that 2 of the planets could experience irradiation levels from their star, similar to those experienced on Earth.
Astronomers have plenty of data to go through
According to the document published online by the Astrophysical Journal Supplement Series, the exoplanets’ orbital periods can vary from 5 and a half to 24 days. According to Ian Crossfield, a Sagan Fellow at the University of Arizona’s Lunar and Planetary Laboratory and lead author of the paper, most of these planets orbit around their host star closer than Mercury orbits around the sun. But still, the possibility of finding life, or the conditions to create it, are not ruled out.
Among the 104 planets, 2 of them orbit in the “habitable zone” where is possible to find water on the surface. This does not mean that they orbit far from their sun, in fact, they still orbit closer to their star than Mercury does around our sun, but it is important to keep in mind that the M dwarf star K2-72 is that, a dwarf star. This means that planets can be closer to it because is smaller and cooler than our host star and thus, its habitable zone is closer to it.
NASA says that 1 of the two planets that possibly can host life, the one closer to the dwarf star, has a 15 day year, which is the time it takes to the newly discovered planet to complete its orbit around its star. The second planet would have a year equivalent to 24 Earth days because it farther from its sun. Regarding temperature, the closer planet is likely to be 10 percent hotter than Earth, and the other planet would be 6 percent cooler than Earth.
How the K2 mission discovered the more than 100 planets
Astronomers had to obtain high-resolution images and high-resolution optical spectroscopy to validate the candidate planets discovered by the K2 mission. They did this dispersing the starlight as through a prism that allows researchers to infer the mass, radius, temperature and other physical properties of a star. With this information, scientists can also understand the properties of planets that orbit the sun, NASA explains.
Steve Howell, who is a project scientist for the K2 mission at NASA’s Ames Research Center in Moffett Field, California says that the recent list of exoplanets highlights that the examination of bright stars and nearby stars provides many interesting planets. He added that the targets ease the astronomical community work of study and characterization of new planets. Regarding the James Webb Space Telescope, Howell said that the discoveries made by the K2 mission are “gems” for the Webb telescope that could help him describe the planet’s atmospheres.
All discoveries made by the Kepler and its K2 mission are milestones for NASA’s other upcoming exoplanets missions: the Transiting Exoplanet Survey Satellite and James Webb Space Telescope.
100+ exoplanets found by @NASAKepler's #K2mission includes 1 star w/ 4 Earth-size worlds: https://t.co/vhEYnbOddK pic.twitter.com/LJsjvLP8zN
— NASA PlanetQuest (@PlanetQuest) July 18, 2016
The Kepler Space Telescope: how does it work and its second chance to discover more planets
Kepler Space Telescope and its newest version created after a failure in its system, the K2 mission, can find new planets using and impressive system. The telescope can measure the subtle dip in a star’s brightness that is caused by a planet’s orbit when passes in front of its star. The Kepler telescope was build to surveyed just one patch of the sky in the northern hemisphere to determine the frequency of planets similar to Earth. The telescope was launched in 2009 and searches planets that are comparable to Earth’s size and temperature that are orbiting a star similar to our sun.
Unfortunately, in 2013, Kepler suffered a hardware failure and started to orbit differently, which make it impossible to the telescope to continue to stare its original target area. But not everything was lost. Thanks to science and some brilliant NASA engineers, the Kepler Space Telescope was fixed using the light from the sun that forces the telescope to stay in place, starting Kepler’s K2 mission.
The Kepler’s new mission covers more of the sky, thus, is capable of observing the more dwarf star and now can detect them even when they are cooler or smaller. The scientific community sets all K2 goals, and it is entirely directed by them, according to NASA.
Discovered: Five gas giants in one solar system, found by @NASAKepler's #K2mission: https://t.co/ZpzxsCkW4L pic.twitter.com/Wt7GToHT6z
— NASA PlanetQuest (@PlanetQuest) July 16, 2016
Source: NASA