Kepler-62 is a

K-type main sequence star A K-type main-sequence star, also referred to as a K-type dwarf or an orange dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars ...

cooler and smaller than the Sun, located roughly 990

light years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

from

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 ...

in the constellation

Lyra Lyra (; Latin for lyre, from Greek ''λύρα'') is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was ...

. It resides within the field of vision of the ''Kepler'' spacecraft, the satellite that

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 Mission The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orb ...

used to detect planets that may be transiting their stars. On April 18, 2013, it was announced that the star has five planets, two of which,

Kepler-62e Kepler-62e (also known by its Kepler Object of Interest designation KOI-701.03) is a super-Earth exoplanet (extrasolar planet) discovered orbiting within the habitable zone of Kepler-62, the second outermost of five such planets discovered by NAS ...

and

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 ...

are within the star's

habitable zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kas ...

. The outermost, Kepler-62f, is likely a

rocky planet A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate Rock (geology), rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the S ...

Nomenclature and history

Prior to Kepler observation, Kepler-62 had the

2MASS The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and ...

catalogue number 2MASS J18525105+4520595. In the Kepler Input Catalog it has the designation of KIC 9002278, and when it was found to have transiting planet candidates it was given the Kepler object of interest number of KOI-701. Planetary candidates were detected around the star by

, a mission tasked with discovering planets in

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 ...

around their stars. The transit method that Kepler uses involves detecting dips in brightness in stars. These dips in brightness can be interpreted as planets whose orbits pass in front of their stars from the perspective of

, although other phenomenon can also be responsible which is why the term planetary candidate is used. Following the acceptance of the discovery paper, the Kepler team provided an additional moniker for the system of "Kepler-62". The discoverers referred to the star as Kepler-62, which is the normal procedure for naming the exoplanets discovered by the spacecraft. Hence, this is the name used by the public to refer to the star and its planets. Candidate planets that are associated with stars studied by the Kepler Mission are assigned the designations ".01", ".02", ".03", ".04", ".05" etc. after the star's name, in the order of discovery. If planet candidates are detected simultaneously, then the ordering follows the order of orbital periods from shortest to longest. Following these rules, the first three candidate planets were detected simultaneously, with orbital periods of 18.16406, 5.714932, and 122.3874 days, respectively, in the 2011 data release, with another two candidate planets, with orbital periods of 267.29 and 12.4417 days, respectively, being detected in a 2012 data release by the ''Kepler'' spacecraft. The designations ''b'', ''c'', ''d'', ''e'', and ''f'' derive from the order of discovery. The designation of ''b'' is given to the first planet orbiting a given star, followed by the other lowercase letters of the alphabet. In the case of Kepler-62, all of the known planets in the system were announced at one time, so ''b'' is applied to the closest planet to the star and ''f'' to the farthest. The name Kepler-62 derives directly from the fact that the star is the catalogued 62nd star discovered by ''Kepler'' to have confirmed planets.

Stellar characteristics

Kepler-62 is a

that is approximately 69% the mass of and 64% the radius of 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 ...

. It has a temperature of 4925 K and is 7 billion years old. In comparison, the Sun is about 4.6 billion years old and has a temperature of 5778 K. The star is somewhat poor in metals, with a

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

( e/H of about –0.37, or about 42% of the amount of iron and other heavier metals found in the Sun, which is similar to that of

Kepler-442 Kepler-442 is a K-type main-sequence star approximately 1,206 light years from Earth in the constellation Lyra. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect pla ...

. The star's luminosity is typical for a star like Kepler-62, with a luminosity of around 21% of that of the solar luminosity. 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 13.75. Therefore, it is too dim to be seen with the naked eye.

Planetary system

All known planets

the star; this means that all five planets' orbits appear to cross in front of their star as viewed from the Earth's perspective. Their

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

s relative to Earth's line of sight, or how far above or below the plane of sight they are, vary by less than one degree. This allows direct measurements of the planets' periods and relative diameters (compared to the host star) by monitoring each planet's transit of the star. The exact eccentricity of the planets are not known but estimates place it very close to 0, giving the planets a mostly circular orbit. The radii of the planets fall between 0.54 and 1.95

Earth radii Earth radius (denoted as ''R''🜨 or R_E) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid, the radius ranges from a maximum of nearly (equatorial radius, deno ...

. Of particular interest are the planets ''e'' and ''f'', as they are the best candidates for solid planets falling into the habitable zone of their star. Their radii, 1.61 and 1.41 Earth radii respectively, put them in a radius range where they may be solid

terrestrial planet A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury, Ve ...

s. Their positions within the Kepler-62 system mean that they fall within Kepler-62's habitable zone: the distance range where, for a given chemical composition (significant amounts of

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

for Kepler-62f, and a protective cloud cover for Kepler-62e), these two planets could have liquid water on their surfaces, perhaps completely covering them. The masses of the planets could not be directly determined using either the radial velocity or the transit timing method; this failure leads to weak upper limits for the planets' masses. For ''e'' and ''f'', that upper limit amounts to 36 and 35

Earth mass An Earth mass (denoted as M_\mathrm or M_\oplus, where ⊕ is the standard astronomical symbol for Earth), is a unit of mass equal to the mass of the planet Earth. The current best estimate for the mass of Earth is , with a relative uncertainty ...

es, respectively; the real masses are expected to be significantly lower. Based on composition models, the real masses of the planets are probably likely to be 2.1, 0.1, 5.5, 4.8, and 2.8 , respectively, taking into the uncertainty in composition and upper mass limits.NASA Kepler Discovers New Potentially Habitable Exoplanets
Abel Mendez. April 18, 2013. Retrieved August 10, 2016.Habitable Exoplanets Catalog
Planetary Habitability Laboratory. Retrieved August 10, 2016. The existence of an additional planet (at a distance of 0.22 AU, between Kepler-62e and Kepler-62f) of the Kepler-62 system was predicted but not detected yet. To keep this highly sensitive to perturbations planetary system stable, no additional giant planets can be located within 30 AU from the parent stars.

Gallery

References

External links

NASA – Mission overview

Kepler – Discoveries – Summary Table
–

.
Kepler – Discovery of New Planetary Systems (2013)

– NYT.
Video (02:27) - NASA Finds Three New Planets in "Habitable Zone" (04/18/2013).
{{Sky, 18, 52, 51.06, +, 45, 20, 59.5 Planetary systems with five confirmed planets K-type main-sequence stars Planetary transit variables Lyra (constellation)