A Super-Earth is a type of exoplanet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although "mini-Neptunes" is a more common term.
An exoplanet is a planet located outside the Solar System. The first evidence of an exoplanet was noted as early as 1917, but was not recognized as such until 2016; no planet discovery has yet come from that evidence. What turned out to be the first detection of an exoplanet was published among a list of possible candidates in 1988, though not confirmed until 2003. The first confirmed detection came in 1992, with the discovery of terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method. As of 18 June 2024, there are 6,140 confirmed exoplanets in 4,527 planetary systems, with 969 systems having more than one planet. This is a list of the most notable discoveries.
Kepler-10, formerly known as KOI-72, is a Sun-like star in the constellation of Draco that lies 607 light-years from Earth. Kepler-10 was targeted by NASA's Kepler spacecraft, as it was seen as the first star identified by the Kepler mission that could be a possible host to a small, transiting exoplanet. The star is slightly less massive, slightly larger, and slightly cooler than the Sun; at an estimated 11.9 billion years in age, Kepler-10 is 2.3 times the age of the Sun.
Kepler-69c is a confirmed super-Earth extrasolar planet, likely rocky, orbiting the Sun-like star Kepler-69, the outermore of two such planets discovered by NASA's Kepler spacecraft. It is located about 2,430 light-years from Earth.
Kepler-62d is the third innermost and the largest exoplanet discovered orbiting the star Kepler-62, with a size roughly twice the diameter of Earth. It was found using the transit method, in which the dimming that a planet causes as it crosses in front of its star is measured. Its stellar flux is 15 ± 2 times Earth's. Due to its closer orbit to its star, it is a super-Venus or, if it has a volatile composition, a hot Neptune, with an estimated equilibrium temperature of 510 K, too hot to sustain life on its surface.
Kepler-62b is the innermost and the second smallest discovered exoplanet orbiting the star Kepler-62, with a diameter roughly 30% larger than Earth. It was found using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It is likely to have an equilibrium temperature slightly higher than the surface temperature of Venus, high enough to melt some types of metal. Its stellar flux is 70 ± 9 times Earth's.
K2-3d, also known as EPIC 201367065 d, is a confirmed exoplanet of probable mini-Neptune type orbiting the red dwarf star K2-3, and the outermost of three such planets discovered in the system. It is located 143 light-years away from Earth in the constellation of Leo. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. It was the first planet in the Kepler "Second Light" mission to receive the letter "d" designation for a planet. Its discovery was announced in January 2015.
K2-33b is a very young super-Neptune exoplanet, orbiting the pre-main-sequence star K2-33. It was discovered by NASA's Kepler spacecraft on its "Second Light" mission. It is located about 456 light-years away from Earth in the constellation of Scorpius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.
Kepler-1229 is a red dwarf star located about 875 light-years (268 pc) away from the Earth in the constellation of Cygnus. It is known to host a super-Earth exoplanet within its habitable zone, Kepler-1229b, which was discovered in 2016.
K2-72 is a cool red dwarf star of spectral class M2.7V located about 217 light-years away from the Earth in the constellation of Aquarius. It is known to host four planets, all similar in size to Earth, with one of them residing within the habitable zone.
K2-72e (also known by its EPIC designation EPIC 206209135.04), is a confirmed exoplanet, likely rocky, orbiting within the habitable zone of the red dwarf star K2-72, the outermost of four such planets discovered in the system by NASA's Kepler spacecraft on its "Second Light" mission. It is located about 217.1 light-years (66.56 parsecs, or nearly 2.0538×1015 km) away from Earth in the constellation of Aquarius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.
LHS 1140 b is an exoplanet orbiting within the conservative habitable zone of the red dwarf LHS 1140. Discovered in 2017 by the MEarth Project, LHS 1140 b is about 5.6 times the mass of Earth and about 70% larger in radius, putting it within the super-Earth category of planets. It was initially thought to be a dense rocky planet, but refined measurements of its mass and radius have found a lower density, indicating that it is likely an ocean world with 9-19% of its mass composed of water. LHS 1140 b orbits entirely within the star's habitable zone and gets 43% the incident flux of Earth. The planet is 49 light-years away and transits its star, making it an excellent candidate for atmospheric studies with ground-based and/or space telescopes.
Kepler-1652b is a super-Earth exoplanet, orbiting within the habitable zone of the red dwarf Kepler-1652 about 822 light-years away in the Cygnus constellation. Discovered by NASA's Kepler spacecraft, Kepler-1652b was first announced as a candidate in 2013, but wasn't validated until four years later in 2017. It is a potential super-Earth with 160% Earth's radius. The planet orbits well within the habitable zone of its system, the region where liquid water can exist on a planet's surface. The planet is an eyeball planet candidate.
K2-141b is a massive rocky exoplanet orbiting extremely close to a K Type orange main-sequence star K2-141. The planet was first discovered by the Kepler space telescope during its K2 “Second Light” mission and later observed by the HARPS-N spectrograph. It is classified as an Ultra-short Period (USP) and is confirmed to be terrestrial in nature. Its high density implies a massive iron core taking up between 30% and 50% of the planet's total mass.
K2-155d is a potentially habitable Super-Earth exoplanet in the K2-155 system. It is the outermost of three known planets orbiting around the K-type star K2-155 in the constellation Taurus. It is one of 15 new exoplanets around red dwarf stars discovered by Japanese astronomer Teruyuki Hirano of the Tokyo Institute of Technology and his team. The team used data from NASA's Kepler Space Telescope during its extended K2 "Second Light" mission. K2-155d orbits near the so-called habitable zone of its system, and has the potential to host liquid water.
K2-229b is an extremely hot, solid, iron-rich exoplanet in a close orbit around the active K-dwarf K2-229 in the constellation Virgo, 335 light years away from Earth.
K2-239 is a small red dwarf star in the constellation Sextans, about 32 parsecs away from Earth. Observed by the Kepler Space Telescope during Campaign 14 of its K2 "Second Light" mission, it was found to have three hot, likely rocky Earth-sized planets in orbit around it.
K2-236b is a Neptune-like exoplanet that orbits an F-type star. It is also called EPIC 211945201 b. Its mass is 27 Earths, it takes 19.5 days to complete one orbit of its star, and is 0.148 AU from its star. Its discovery was announced in 2018. This was the first exoplanet discovered by scientists based in India. The discoverers were Abhijit Chakraborty (PRL), Arpita Roy (Caltech), Rishikesh Sharma (PRL), Suvrath Mahadevan, Priyanka Chaturvedi, Neelam J.S.S.V Prasad (PRL), and B. G. Anandarao (PRL).
K2-288Bb is a super-Earth or mini-Neptune exoplanet orbiting in the habitable zone of K2-288B, a low-mass M-dwarf star in a binary star system in the constellation of Taurus about 226 light-years from Earth. It was discovered by citizen scientists while analysing data from the Kepler spacecraft's K2 mission, and was announced on 7 January 2019. K2-288 is the third transiting planet system identified by the Exoplanet Explorers program, after the six planets of K2-138 and the three planets of K2-233.
K2-332 b is a potentially habitable Super-Earth or Mini-Neptune exoplanet with a radius of 2.2 earths. It is in the empirical habitable zone, receiving 1.17 times the light that Earth gets from the sun. Its star, K2-332, is type M4V, with a temperature of ~3300 K. It was detected using the transit method in 2016 and is 402 light-years away.
