Kepler-62b (also known by its Kepler Object of Interest designation ''KOI-701.02'') is the innermost and the second smallest discovered

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

orbiting the star

Kepler-62 Kepler-62 is a K-type main sequence star cooler and smaller than the Sun, located roughly 990 light years from Earth in the constellation Lyra. It resides within the field of vision of the ''Kepler'' spacecraft, the satellite that NASA' ...

, with a diameter roughly 30% larger than

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. It was found using the

transit method Any planet is an extremely faint light source compared to its parent star. For example, a star like the Sun is about a billion times as bright as the reflected light from any of the planets orbiting it. In addition to the intrinsic difficulty o ...

, 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 Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...

(around ), high enough to melt some types of metal. Its stellar flux is 70 ± 9 times Earth's.

Physical characteristics

Mass, radius and temperature

Kepler-62b is a

super-Earth A super-Earth is an extrasolar planet 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 ...

, an exoplanet with a radius and mass bigger than Earth but smaller than that of the ice giants

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

and

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...

. It has an

equilibrium temperature The planetary equilibrium temperature is a theoretical temperature that a planet would be if it were a black body being heated only by its parent star. In this model, the presence or absence of an atmosphere (and therefore any greenhouse effect) is ...

of . This is hot enough to melt some types of metal. It has a radius of 1.3 , placing it below the estimated radius of ≤1.6 where it would otherwise be a

mini-Neptune A Mini-Neptune (sometimes known as a gas dwarf or transitional planet) is a planet less massive than Neptune but resembling Neptune in that it has a thick hydrogen–helium atmosphere, probably with deep layers of ice, rock or liquid oceans (made ...

with a volatile composition, with no solid surface. However, the mass is currently not known, estimates place an upper limit of <9 , the actual mass is expected to be significantly lower than this.

Host star

The planet orbits a ( K-type)

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

named

, orbited by a total of five planets, of which

Kepler-62f Kepler-62f (also known by its Kepler Object of Interest designation ''KOI-701.04'') is a super-Earth exoplanet orbiting within the habitable zone of the star Kepler-62, the outermost of five such planets discovered around the star by NASA's ''Ke ...

has the lengthiest orbital period. The star has a mass of 0.69 and a radius of 0.64 . It has a temperature of 4925 K and is 7 billion years old. In comparison, the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

is 4.6 billion years old and has a surface temperature of 5778 K. The star's

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

, or how bright it appears from Earth's perspective, is 13.65. Therefore, it is too dim to be seen with the naked eye.

Orbit

Kepler-62b orbits its host star with an orbital period of 5 days at a distance of about 0.05 AU (compared to the same distance as

Mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

from the Sun, which is about 0.38 AU). It receives 70 times as much

sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...

than Earth does from the Sun.

Discovery

In 2009,

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws o ...

spacecraft was completing observing stars on its

photometer A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, ph ...

, the instrument it uses to detect

transit Transit may refer to: Arts and entertainment Film * ''Transit'' (1979 film), a 1979 Israeli film * ''Transit'' (2005 film), a film produced by MTV and Staying-Alive about four people in countries in the world * ''Transit'' (2006 film), a 2006 ...

events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed stars in the

Kepler Input Catalog The Kepler Input Catalog (or KIC) is a publicly searchable database of roughly 13.2 million targets used for the Kepler Spectral Classification Program (SCP) and ''Kepler''. Overview The Kepler SCP targets were observed by the 2MASS project ...

, including Kepler-62; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Observations for the potential exoplanet candidates took place between 13 May 2009 and 17 March 2012. After observing the respective transits, which for Kepler-62b occurred roughly every 5 days (its orbital period), it was eventually concluded that a planetary body was responsible for the periodic 5-day transits. The discovery, along with the planetary system of the star

Kepler-69 Kepler-69 (''KOI-172'', ''2MASS J19330262+4452080'', KIC 8692861') is a G-type main-sequence star similar to the Sun in the constellation Cygnus, located about from Earth. On April 18, 2013 it was announced that the star has two planet ...

were announced on April 18, 2013.

References

{{Sky, 18, 52, 51.06019, +, 45, 20, 59.507 Exoplanets discovered in 2013 Kepler-62 Transiting exoplanets Lyra (constellation) 62d