Super-Earth’ found orbiting Sun’s nearest single star' - Complete Analysis

• Astronomers have discovered a potentially hospitable planet about 3 times the size of the earth orbiting the nearest solitary star from our Sun.

Highlights

• The cold ‘super earth’ discovered is found to be orbiting Barnard's Star which is the closest single star to our Sun.
• The ‘Barnard’s star b’, as the planet is called is found to be a frozen, dimly lit world with temperature of -170 degree centigrade at least 3.2 times heavier than Earth.
• According to findings the planet is said to be orbiting the Barnard's Star once every 233 days.
• The scientists used radial velocity method to detect the exoplanet.

Where is it found?

• Contrary to popular expectations the potentially hospitable frozen planet lies at a region from the star known as the ‘snow line’.
• Snow line of a star is beyond the habitable zone in which conditions of life could possibly exist like temperature, liquid water etc.
• The cold ‘super-earth’ though lies in the ‘snow line’ could possibly have a substantial atmosphere that rise the temperature and make it potentially more hospitable.

About Bernard’s star

• Barnard's star is the closest single star and the second closest star system to the Sun.
• The closest star to our solar system is a triple star system called Alpha Centauri star system.
• While Alpha Centauri star system is 4 light years away, Bernard’s star is 6 light years away.
• Bernard’s star is a faint low-mass red dwarf like Alpha Centauri triple stellar system.

Exoplanets

• Planets outside our solar system are called exoplanets.
• Most exoplanets are part of star systems.
• Besides there are some “rogue” exoplanets that are not a part of any star system.
• According to NASA there are 3449 confirmed exoplanets from among 4,669 candidates in 2,577 solar systems.
• The search for exoplanets is also the search for alien life and habitable spaces beyond our star system.
• NASA’s Kepler and K2 missions have identified several such candidates.  
• In order to be considered habitable exoplanets must orbit within a distance of their stars in which liquid water can exist on the planet’s surface.
• This distance is called the Goldilocks zone.
• It is found that red dwarfs are the best place to find ‘exoplanets’.

Radial Velocity method

• While the gravity of the star makes the planet revolve around it, planet’s weaker gravity can make the star to wobble.
• If astronomers can detect the star’s wobbling motion, they could tell that there was a large planet orbiting the star.
• A wobbling star will alternately move away from and toward the planet.
• In the radial velocity method, astronomers measure the Doppler shift of the star’s spectrum as it moves alternately toward and away from the Earth.
• The amount of Doppler shift determines the size of the star’s orbit, which in turn tells us about the unseen planet’s orbit.