Exoplanets Discovered

The large majority of exoplanets found to date are within just a few hundred light years of Earth. However, as we keep scouring the skies we are slowly finding new ones farther afield. Here, we’ve mapped some of the most notable planets across the Milky Way.

SWEEPS-04

This exoplanet is the most distant discovered to date. It is approximately 22,000 light years from us, and has a mass 3.8 times that of Jupiter despite being thought to only have 0.81 times its radius. It orbits very close to Its host star, about 0.055 AU, taking just 4.2 days to complete an orbit. It was found using the transit method.

KOI-428b

This hot Jupiter planet, In orbit around a red giant 8,800 light years away, was spotted using the transit method by Kepler. It is twice as big as Jupiter but up to 13 times its temperature, making It comparable In density to Neptune but hotter than Mercury. In fact, it orbits five times closer to Its parent star than Mercury does to the Sun.

Kepler-22b

This exoplanet could be one of the most Earth-like discovered to date. Positioned 600 light years from our world, Kepler-22b is known to orbit comfortably within its host star’s habitable zone.

KOI-961-02

This planet Is part of a system of three orbiting the red dwarf star KOI-961, where KOI stands for Kepler Object of Interest. It is 0.78 times the size of Earth and 126 light years from the Sun. The planets were discovered by the Kepler telescope using the transit method. It was only the second system discovered to have planets which were less than Earth’s radius. Its temperature is 728K (455“C/850“F) and it has the shortest orbital period we know of.

MOA-2011-BLG-293L b

This planet, 2.4 times the size of Jupiter, is roughly 7,000 light years from Earth and orbits its host star at an Earth-like distance of 1AU. Found in early-2012, it is one of the more recent distant planets to be discovered.

OGLE-2005-BLG-0390Lb

This planet, in orbit around a red dwarf star, is the most distant planet found to date. It Is a super-Earth located roughly 21,500 light years away near the centre of the Milky Way. It does not appear to have the capability to support life. It has a mass about five and a half times that of Earth. However, It is a super-chilly planet, with a temperature of only about 50K (-220“C/-370“F) and It takes ten Earth years to orbit its star.

NGC 4349 No 127 b

This large gas giant 7,100 light years away, is up to 20 times the mass of Jupiter. For this reason it is possible that It could be a brown dwarf, but currently it Is classed as a gas giant. Its orbit Is quite elliptical, like Mercury In our solar system. It takes 678 days to orbit its star at a distance of 2.38 AU and was found using the radial-velocity technique.

HD 85512 b

This exoplanet in orbit around an orange dwarf called Gliese 370 is one of the most potentially habitable planets discovered to date. It is 36 light years from Earth, and has a mass about 3.6 times that of our home planet but, due to it being larger, has an estimated surface gravity of 1.4 g. Its predicted temperature is 24“C (75“F), though, which is well within the range for liquid water, and so life, to exist.

Epsilon Eridani b

Discovered back in 2000 using the radial-velocity method, this gas giant with about 1.56 times the mass of Jupiter is the closest-known exoplanet to Earth. It orbits Its host star at a distance of 3.4 AU in 2,500 Earth days.

WASP-17b

This planet is about half the mass of Jupiter but is almost twice its size, making it both the largest planet found to date and the least dense.

PSR B1257 +12a

At just twice the mass of Earth’s moon, this pulsar planet (pictured right) is the smallest-known exoplanet to date in our galaxy. It orbits its star at about 0.2 AU.

PSR J1719-1438 b

This pulsar planet, discovered around a millisecond pulsar (MSP) in late-2011, is the densest planet found to date and is thought to be possibly made of diamond.

KOI-55 b

This terrestrial planet roughly four times the mass of Earth has the shortest-known orbit of its host star, completing a lap in just under six hours.

PSR B1620-26 b

Also known as Methuselah or the Genesis planet, this exoplanet Is estimated to be 12.7 billion years old, making it currently the oldest-known planet in the universe.

OGLE-2005-BLG-390Lb

The most distant exoplanet discovered to date is this planet with a mouthful of a name. It Is just over five times the mass of Earth but is quite far from its star so is believed to be very icy.