Kepler-10
Encyclopedia
Kepler-10, formerly known as KOI-72, is a sunlike star in constellation Draco
that lies 173 parsec
s (564 light years) away from the Earth. Kepler-10 was targeted by NASA
's Kepler spacecraft, as it was seen the first star identified by the Kepler mission as 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 almost 2.6 times the age of the Sun. Kepler-10 is host to a planetary system
made up of at least two planets. Kepler-10b
, the first undeniably rocky planet, was discovered in its orbit after eight months of observation and announced on January 10, 2011. The planet orbits its star closely, completing an orbit every 0.8 days, and has a density similar to that of iron. The second planet, Kepler-10c, was confirmed on May 23, 2011, based on follow-up observations by the Spitzer Space Telescope
. The data shows it has an orbital period of 42.3 days.
that transit, or cross in front of, their host stars with respect to Earth
. The transit slightly dims the host star; this periodic dimming effect is then noted by Kepler. After eight months of observation ranging from May 2009 to January 2010, the Kepler team established Kepler-10b as the first rocky exoplanet discovered by the Kepler satellite. Kepler-10 was the first Kepler-targeted star suspected of having a small planet in orbit. Because of that, verifying Kepler's discovery was prioritized by telescopes at the W.M. Keck Observatory in Hawaii. The discovery was successfully verified. Although there had been many potentially rocky exoplanets discovered in the past, Kepler-10b was the first definitively rocky planet to have been discovered.
The discovery of Kepler-10b was announced to the public at a winter meeting of the American Astronomical Society
on January 10, 2011 in Seattle. On May 23, 2011, the existence of Kepler-10c was confirmed at the 218th AAS meeting in Boston.
. With a mass of 0.895 (± 0.06) Msun
and a radius of 1.056 (± 0.021) Rsun, the star is approximately 10% smaller than and 5% wider than the Sun. The metallicity
of Kepler-10, as measured in [Fe/H] (the amount of iron
in the star), is -0.15 (± 0.04); this means that Kepler-10 is about 70% less metal-rich than the Sun. Metallicity tends to play a large role in the formation of planets, determining if they form, and what kind of planet they will form. In addition, Kepler-10 is estimated to be 11.9 billion years old and to have an effective temperature
of 5627 (± 44) K; To compare, the Sun is younger and hotter, with an age of 4.6 billion years and an effective temperature of 5778 K.
Kepler-10 is located at a distance of 173 (± 27) parsecs from the Earth, which equates to approximately 564 light years. Also, Kepler-10's apparent magnitude
, or brightness as seen from Earth, is 10.96; it therefore cannot be seen with the naked eye
.
, the first definitively rocky exoplanet, was discovered in the orbit of Kepler-10. The planet has a mass that is 4.56 times that of Earth's and a radius that is 1.416 times that of Earth. The planet's estimated density is 8.8 g/cm³, or 880% that of water. This is similar to that of iron
. The planet orbits Kepler-10 at a distance of 0.01684 AU
every 0.8375 days; this can be compared to the orbit and orbital period
of planet Mercury
, which circles the Sun at a distance of 0.3871 AU every 87.97 days. Because the planet orbits so closely to its star, its eccentricity
is virtually zero. It, thus, has an extremely circular orbit.
Kepler-10c is an exoplanet that was also discovered by NASA's Kepler Mission
in the orbit of Kepler-10. Measurements of the body suggest that it has a mass of at most 0.063 MJ
and a radius of 0.199 RJ (2 Earth radii). Kepler-10c would orbit Kepler-10 at a distance of 0.24 AU every 42.29 days.
Draco (constellation)
Draco is a constellation in the far northern sky. Its name is Latin for dragon. Draco is circumpolar for many observers in the northern hemisphere...
that lies 173 parsec
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
s (564 light years) away from the Earth. Kepler-10 was targeted by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Kepler spacecraft, as it was seen the first star identified by the Kepler mission as 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 almost 2.6 times the age of the Sun. Kepler-10 is host to a planetary system
Planetary system
A planetary system consists of the various non-stellar objects orbiting a star such as planets, dwarf planets , asteroids, meteoroids, comets, and cosmic dust...
made up of at least two planets. Kepler-10b
Kepler-10b
Kepler-10b is the first confirmed terrestrial planet to have been discovered outside the Solar System. Discovered after several months of data collection during the course of the NASA-directed Kepler Mission, which aims to discover Earth-like planets crossing in front of their host stars, the...
, the first undeniably rocky planet, was discovered in its orbit after eight months of observation and announced on January 10, 2011. The planet orbits its star closely, completing an orbit every 0.8 days, and has a density similar to that of iron. The second planet, Kepler-10c, was confirmed on May 23, 2011, based on follow-up observations by the Spitzer Space Telescope
Spitzer Space Telescope
The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
. The data shows it has an orbital period of 42.3 days.
Nomenclature and history
Kepler-10 was named because it was the tenth planetary system observed by the Kepler spacecraft, a NASA satellite designed to search for Earth-like planetsTerrestrial 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 are the inner planets closest to the Sun...
that transit, or cross in front of, their host stars with respect to Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. The transit slightly dims the host star; this periodic dimming effect is then noted by Kepler. After eight months of observation ranging from May 2009 to January 2010, the Kepler team established Kepler-10b as the first rocky exoplanet discovered by the Kepler satellite. Kepler-10 was the first Kepler-targeted star suspected of having a small planet in orbit. Because of that, verifying Kepler's discovery was prioritized by telescopes at the W.M. Keck Observatory in Hawaii. The discovery was successfully verified. Although there had been many potentially rocky exoplanets discovered in the past, Kepler-10b was the first definitively rocky planet to have been discovered.
The discovery of Kepler-10b was announced to the public at a winter meeting of the American Astronomical Society
American Astronomical Society
The American Astronomical Society is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC...
on January 10, 2011 in Seattle. On May 23, 2011, the existence of Kepler-10c was confirmed at the 218th AAS meeting in Boston.
Characteristics
Kepler-10 is a G-type star, like the SunSun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. With a mass of 0.895 (± 0.06) Msun
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
and a radius of 1.056 (± 0.021) Rsun, the star is approximately 10% smaller than and 5% wider than the Sun. The metallicity
Metallicity
In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium...
of Kepler-10, as measured in [Fe/H] (the amount of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
in the star), is -0.15 (± 0.04); this means that Kepler-10 is about 70% less metal-rich than the Sun. Metallicity tends to play a large role in the formation of planets, determining if they form, and what kind of planet they will form. In addition, Kepler-10 is estimated to be 11.9 billion years old and to have an effective temperature
Effective temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation...
of 5627 (± 44) K; To compare, the Sun is younger and hotter, with an age of 4.6 billion years and an effective temperature of 5778 K.
Kepler-10 is located at a distance of 173 (± 27) parsecs from the Earth, which equates to approximately 564 light years. Also, Kepler-10's apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
, or brightness as seen from Earth, is 10.96; it therefore cannot be seen with the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
.
Planetary system
Kepler-10bKepler-10b
Kepler-10b is the first confirmed terrestrial planet to have been discovered outside the Solar System. Discovered after several months of data collection during the course of the NASA-directed Kepler Mission, which aims to discover Earth-like planets crossing in front of their host stars, the...
, the first definitively rocky exoplanet, was discovered in the orbit of Kepler-10. The planet has a mass that is 4.56 times that of Earth's and a radius that is 1.416 times that of Earth. The planet's estimated density is 8.8 g/cm³, or 880% that of water. This is similar to that of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. The planet orbits Kepler-10 at a distance of 0.01684 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
every 0.8375 days; this can be compared to the orbit and orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of planet Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
, which circles the Sun at a distance of 0.3871 AU every 87.97 days. Because the planet orbits so closely to its star, its eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
is virtually zero. It, thus, has an extremely circular orbit.
Kepler-10c is an exoplanet that was also discovered by NASA's Kepler Mission
Kepler Mission
The Kepler spacecraft is an American space observatory, the space-based portion of NASA's Kepler Mission to discover Earth-like planets orbiting other stars. The spacecraft is named in honor of the 17th-century German astronomer Johannes Kepler...
in the orbit of Kepler-10. Measurements of the body suggest that it has a mass of at most 0.063 MJ
Jupiter mass
Jupiter mass , is the unit of mass equal to the total mass of the planet Jupiter . Jupiter mass is used to describe masses of the gas giants, such as the outer planets and extrasolar planets. It is also used in describing brown dwarfs....
and a radius of 0.199 RJ (2 Earth radii). Kepler-10c would orbit Kepler-10 at a distance of 0.24 AU every 42.29 days.