An Exoplanet is Just Next Door!
An international team of scientists from nine countries announced that an earth-like world has been found orbiting the nearest star Proxima Centauri, the closest star to our sun.
The discoverers named the new planet Proxima Centauri b which is 4.2 light years away from home.
The team is headed by Dr. Guillem Anglada-Escud of the Queen Mary University of London with the collaboration of Dr. Aviv Ofir from Weizmann Institute of Sciences.
Meet Proxima Centauri b
Scientists calculated that Proxima Centauri b has a mass of at least 1.3 times that of Earth. It takes only 11 days for the newly discovered planet to orbit its sun.
Since its sun is so dim, the temperature on Proxima Centauri b is warm enough for liquid water. The range of distances where a planet’s temperature permits liquid water is commonly referred to as the habitable zone.
The newly discovered planet was discovered with an observatory in Chile. However, the earth-mass planet cannot be seen in Israel. The scientists explained that the planet is below the southern horizon, making it unobservable from the Middle East all year round.
How Proxima Centauri b was Discovered
Proxima Centauri b was discovered through measurements of the radial velocity of the star. These measurements depend on the Doppler effect, also known as the shift in wavelength as an object moves closer or away from the viewer.
According to the scientists, the star is moving at a speed of about a meter a second (or 3.6 km/h) towards and away from Earth. The scientists explain that the orbiting planet and its star are both orbiting a shared center of gravity.
Since the mass of the star is greater than that of its planets, that center of gravity is usually close to center of the star, and planets make the star’s motion appear as a wobble. Interestingly, this wobble can be detected by today’s instruments.
Proxima Centauri is a red dwarf a star with a diameter about one-seventh that of our Sun, and far dimmer. It gives off only 1/600 the light of our Sun.
