Seventh TRAPPIST-1 Planet Confirmed
The small red dwarf star M8 TRAPENSE-1 became famous after astronomers have discovered seven small exoplanets orbiting around it. By the time the scouts made the announcement in February, they could not say much about the ultrapériphé world marked: Astronomers had seen the world – or at least they thought it was a planet – going through the star only once.
Rodrigo Luger (University of Washington, Seattle) and his colleagues, including members of the original discovery team have now confirmed Planet M and some of its specifications.
The team used more than 70 days of data from the Kepler spacecraft reused by NASA, taken as part of its K2 mission. The spacecraft has detected h across its star four times, with an orbital period of 18.77 – just what researchers expect, based on their previous observations. (They also analyzed the data in three different ways, just to be sure). This orbit places the exoplanet well out of the habitable zone of TRAPENSE-1: the amount of energy received by the tiny star planet is at the height of the dwarf planet Ceres receives Du Soleil, at his home in the main asteroid belt.
Transits reveal that planet h is 75% as wide as Earth, or about 40% higher than in March. But we still do not know the global mass. The researchers used small equipment in the six transit times of exoplanets to estimate their gravitational influence on each other and, therefore, their masses. Unfortunately, Planet M’s metered traffic is not clean enough to reveal the weather changes due to the gravitational pull of its siblings, Luger said.
The orbital period of the exoplanet is a complicated pattern with periods of those around it, the authors explain May 22 in nature astronomy. Normally, when we talk about resonant orbits, we think of situations like the Galilean moons of Jupiter for each circuit, Ganymede does around Jupiter, Europe makes two. The TRAPENSE-1 planets have a more complicated arrangement, known as Laplace’s higher-order resonance, in which the pattern is a combination of three periods that do not exactly produce the simple and simple multiple as we normally think. For those interested in mathematics, the relationship is
X / P1 – (x + y) / y + P2 / P3 = 0
Where x and y are integers and P1, P2 and P3 are the orbital periods of planet 1, to planet 2 and 3 in the planet body neighbor trio is compared.
For those who are not interested in mathematics, know that for every two laps, the planet is about TRAPENSE h-1, the planet is about 3 g, and the planet is f (more or less) four. The exoplanets have migrated in this complex array arrangement some time after the system is formed, then it is gravitently blocked.
How old is TRAPENSE-1?
Luger’s team also tried to limit the age of TRAPENSE-1. The appointment as expensive stars as it is difficult. How an old star depends on its mass; In a mass of 8% of the mass of the Sun, TRAPENSE-1 will age very slowly.
With K2 data, astronomers could use the stars to see the period of rotation of the dwarfs at 3.3 days (approximately twice as long as the previously reported period). It’s half way to ultra cool dwarf stars. Kepler has not found much activity, but caught at least one significant spark. Based on the level of spin and activity, the authors estimate that the star’s age is between 3 and 8 billion years.