Bone-crushingly cold Super Earth discovered orbiting nearby star
18 November, 2018, 23:18
The planet, Barnard's Star b, is the second-closest exoplanet (a planet outside of our solar system) to Earth, per USA Today.
Barnard's Star, a red dwarf star located in a solar system about six light-years away from Earth, may have some company. This would place the planet at the so-called snow-line of the star, where it is likely to be a frozen world.
Its surface temperature would not exceed -170 ° C, which excludes to find water in the liquid state and therefore life as we know it.
The team used the method called radial velocity, which uses the Doppler shifts of a star's light to measure the tug of a nearby planet. There are many, many stars that are thousands of light-years and millions of light-years away. The mass of Barnard's star is 0.17 mass of the Sun, and she is older than our star twice, she was inactive and very tiresome, the luminosity of the star is about 0,0004 Sunny.
Even if it is close to its star [0.4 times the distance between the Earth and the Sun], it would receive only 2% of the energy that the Earth receives from the Sun. "Fortunately, our long-running Keck planet search program gave us the years we needed to gather enough precision radial velocity data with HIRES to begin to sense the presence of a planet".
It's really near and therefore if you have the hope - like I do - of eventually seeing these planets to study them in detail we have to start with the immediate ones. "The combination of all data led to a total of 771 measurements - a huge amount of information!" It finishes its one revolution in 233 days.
One light year is equal to the distance travelled by light in one year so any visible light from the newly discovered planet is six years old. "After a very careful analysis, we are over 99 per cent confident that the planet is there, since this is the model that best fits our observations", said Ignasi Ribas from the Institute of Space Sciences in Spain. That designation is held by the roughly Earth-size world Proxima b, which orbits Proxima Centauri, one of the Alpha Centauri trio. "However, we must remain cautious and collect more data to nail the case in the future, because natural variations of the stellar brightness resulting from star spots can produce similar effects to the ones detected".
The team worked with the European Southern Observatory using astronomical instruments so accurate they can detect changes in a star's velocity as small as 3.5 kilometres per hour - a gentle walking pace.