Kepler-14
Encyclopedia
Kepler-14 is a binary star
system targeted by the Kepler spacecraft. It is host to one known planet: the Jupiter-like Kepler-14b
. The star system was identified early by Kepler as a possible planetary host, but when imaging revealed that Kepler-14 was a binary star system and not a single star, the confirmation process was protracted. The stars are separated by at least 280 AU, and the stars complete an orbit around a common center of mass every 2800 years. Both stars are larger than the Sun; they are both of similar absolute magnitude
s. However, the primary star is brighter as seen from Earth.
launched the satellite in April 2009. Kepler-14 was provisionally designated KOI-98. Because Kepler-14's transit signal seemed to imply that the possible planet had a short orbit and a clear effect on Kepler-14's brightness, the Kepler science team forwarded the candidate to the Kepler Follow-up Program
(KFOP).
KFOP used the Fibre-fed Échelle Spectrograph (FIES) on the Nordic Optical Telescope
to measure Kepler-14's radial velocity
in October 2009. Other radial velocity measurements were collected using W.M. Keck Observatory. The FIES and Keck data, combined with speckle imaging
data from WIYN Observatory
and near-infrared adaptive optics
measurements at Palomar Observatory
and the MMT Observatory
, revealed that Kepler-14 was actually a closely knit binary star
, something that radial velocity data alone could not recognize. Because of this new discovery, further investigation of Kepler-14 was postponed until after the publishing of the first five new Kepler planets (the ones orbiting Kepler-4
, Kepler-5
, Kepler-6
, Kepler-7
, and Kepler-8
). Analysis of the collected data revealed that, of the two component stars in the Kepler-14 system, both stars are of nearly equal magnitude, although one of the stars was fainter. The brighter star was designated the "A" component, and the fainter star received the "B" designation. The transit signal was also observed in orbit around the A component of the system, meaning that the planetary candidate would be in orbit of the primary star of Kepler-14. On August 7, 2010, the Infrared Array Camera on the Spitzer Space Telescope
observed Kepler-14 to gather photometric
data. The photometric data confirmed this idea.
Analysis of both the Spitzer photometric data and the radial velocity data confirmed the idea of a planet as the source of the transit signal. The planet was designated Kepler-14b
, and was published alongside the data and research on Kepler-14 in a June 2011 paper. In the discovery paper, Kepler-14's nature as a close binary star was almost missed by the astronomers, and would not have been known if high-resolution imaging of the star had not been undertaken. The Kepler team acknowledged that a number of transiting planets' host stars may have actually been close visual binaries, and that (as a result) the characteristics of the stars and their planets may be incorrect. As a result of their studies into Kepler-14, the Kepler team suggested the implementation of a high-resolution imaging campaign to re-examine transiting planet hosts, an effort which would only require a modest amount of telescope time.
. The estimated orbital period
of the Kepler-14 binary system is approximated at 2800 years The two stars are of nearly equal brightness, but the primary component is slightly brighter as seen from Earth. The primary star has an estimated mass of 1.51 times that of the Sun
, and the secondary has an estimated mass of 1.39 times the Sun's mass.
Because Kepler-14 is so close-knit as seen fron Earth, it was impossible for the discovery team to separate the two stars and analyze their characteristics as separate stars. The Kepler team analyzed their characteristics anyways under the assumption that Kepler-14 was a single star. Kepler-14 is a binary star whose two components are separated by at least 280 distances between the Earth and Sun
. The estimated orbital period
of the Kepler-14 binary system is approximated at 2800 years The two stars are of nearly equal brightness, but the primary component is slightly brighter as seen from Earth. The primary star has an estimated mass of 1.51 times that of the Sun
, and the secondary has an estimated mass of 1.39 times the Sun's mass. The Kepler-14 system is 980 parsec
s (3,196 light years) from Earth. It has an apparent magnitude
of 12.12, and thus cannot be seen with the unaided eye.
Because Kepler-14 is so close-knit as seen fron Earth, it was impossible for the discovery team to separate the two stars and analyze their characteristics as separate stars. The Kepler team analyzed their characteristics anyways under the assumption that Kepler-14 was a single star.
If Kepler-14 were a single star, it would be an F-type star with a mass of 1.512 times the Sun's, and a size that is 2.048 times the Sun's radius. As a single star, the effective temperature
of Kepler-14 would be 6395 K, much hotter than the Sun, and the star's iron content
would be 0.12, or 132% the amount found in the Sun. Assuming that Kepler-14's two stars formed at about the same time, their gyrochronological age
s would be approximately 2.2 billion years.
-like planet in the orbit of the primary star of Kepler-14. The planet is 8.4 times Jupiter's mass
, the equivalent of 2670 times Earth's mass. The planet is slightly larger than Jupiter at 1.14 Jupiter radii The density of Kepler-14b is 7.1 grams/cm3, the second densest planet confirmed by the Kepler spacecraft after Kepler-10b
. Kepler-14b completes an orbit every 6.79 days with a slightly irregular orbit indicated its orbital eccentricity
of 0.035.
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system targeted by the Kepler spacecraft. It is host to one known planet: the Jupiter-like Kepler-14b
Kepler-14b
Kepler-14b is an extrasolar planet in orbit around the primary star of the binary Kepler-14 system. It is currently the only planet known to exist in this star system. Kepler-14b is 8.4 times the mass of Jupiter and has a radius 1.14 times that of Jupiter, and it orbits its host star every 6.79 days...
. The star system was identified early by Kepler as a possible planetary host, but when imaging revealed that Kepler-14 was a binary star system and not a single star, the confirmation process was protracted. The stars are separated by at least 280 AU, and the stars complete an orbit around a common center of mass every 2800 years. Both stars are larger than the Sun; they are both of similar absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
s. However, the primary star is brighter as seen from Earth.
Observational history
Kepler-14 was identified as a possible host to a planet as early as the first four months of Kepler's operational data, which began when NASANASA
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...
launched the satellite in April 2009. Kepler-14 was provisionally designated KOI-98. Because Kepler-14's transit signal seemed to imply that the possible planet had a short orbit and a clear effect on Kepler-14's brightness, the Kepler science team forwarded the candidate to the Kepler Follow-up Program
Kepler Follow-up Program
The Kepler-Follow-up Program, known also as the Kepler Follow-up Observation Program and KFOP, is a program instituted to conduct follow-up observations on Kepler Objects of Interest , or signals noticed by the Kepler spacecraft that may indicate the presence of a planet transiting its host star...
(KFOP).
KFOP used the Fibre-fed Échelle Spectrograph (FIES) on the Nordic Optical Telescope
Nordic Optical Telescope
The Nordic Optical Telescope is an astronomical telescope located at Roque de los Muchachos Observatory, La Palma in the Canary Islands. First light came in 1988, with regular observing beginning in 1989. It is funded by Denmark, Sweden, Iceland, Norway and Finland...
to measure Kepler-14's radial velocity
Radial velocity
Radial velocity is the velocity of an object in the direction of the line of sight . In astronomy, radial velocity most commonly refers to the spectroscopic radial velocity...
in October 2009. Other radial velocity measurements were collected using W.M. Keck Observatory. The FIES and Keck data, combined with speckle imaging
Speckle imaging
Speckle imaging describes a range of high-resolution astronomical imaging techniques based either on the shift-and-add method or on speckle interferometry methods...
data from WIYN Observatory
WIYN Observatory
The WIYN Observatory is owned and operated by the WIYN Consortium. Its telescope, a 3.5-meter instrument, is the newest and second largest telescope on Kitt Peak in Arizona...
and near-infrared adaptive optics
Adaptive optics
Adaptive optics is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion, and in retinal imaging systems to reduce the...
measurements at Palomar Observatory
Palomar Observatory
Palomar Observatory is a privately owned observatory located in San Diego County, California, southeast of Pasadena's Mount Wilson Observatory, in the Palomar Mountain Range. At approximately elevation, it is owned and operated by the California Institute of Technology...
and the MMT Observatory
MMT Observatory
The MMT Observatory is an astronomical observatory on the site of Fred Lawrence Whipple Observatory . The Whipple observatory complex is located on Mount Hopkins, Arizona, USA in the Santa Rita Mountains...
, revealed that Kepler-14 was actually a closely knit binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
, something that radial velocity data alone could not recognize. Because of this new discovery, further investigation of Kepler-14 was postponed until after the publishing of the first five new Kepler planets (the ones orbiting Kepler-4
Kepler-4
Kepler-4 is a sunlike star located about 1631 light-years away in the constellation Draco. It is in the field of view of the Kepler Mission, a NASA operation purposed with finding Earth-like planets. Kepler-4b, a Neptune-sized planet that orbits extremely close to its star, was discovered in its...
, Kepler-5
Kepler-5
Kepler-5 is a star located in the constellation Cygnus in the field of view of the Kepler Mission, a NASA project aimed at detecting planets in transit of, or passing in front of, their host stars as seen from Earth. One closely orbiting, Jupiter-like planet, named Kepler-5b, has been detected...
, Kepler-6
Kepler-6
Kepler-6 is a yellow giant situated in the constellation Cygnus. The star lies within the field of view of the Kepler Mission, which discovered it as part of a NASA-led mission to discover Earth-like planets...
, Kepler-7
Kepler-7
Kepler-7 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA operation in search of Earth-like planets. It is home to the fourth of the first five planets that Kepler discovered; this planet, a Jupiter-size gas giant named Kepler-7b, is as light as styrofoam...
, and Kepler-8
Kepler-8
| class=F5VKepler-8 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is slightly hotter, larger, and more massive than the Sun, has one gas giant in its orbit, Kepler-8b. This...
). Analysis of the collected data revealed that, of the two component stars in the Kepler-14 system, both stars are of nearly equal magnitude, although one of the stars was fainter. The brighter star was designated the "A" component, and the fainter star received the "B" designation. The transit signal was also observed in orbit around the A component of the system, meaning that the planetary candidate would be in orbit of the primary star of Kepler-14. On August 7, 2010, the Infrared Array Camera on 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...
observed Kepler-14 to gather photometric
Photometry (astronomy)
Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...
data. The photometric data confirmed this idea.
Kepler-14b
Kepler-14b is an extrasolar planet in orbit around the primary star of the binary Kepler-14 system. It is currently the only planet known to exist in this star system. Kepler-14b is 8.4 times the mass of Jupiter and has a radius 1.14 times that of Jupiter, and it orbits its host star every 6.79 days...
, and was published alongside the data and research on Kepler-14 in a June 2011 paper. In the discovery paper, Kepler-14's nature as a close binary star was almost missed by the astronomers, and would not have been known if high-resolution imaging of the star had not been undertaken. The Kepler team acknowledged that a number of transiting planets' host stars may have actually been close visual binaries, and that (as a result) the characteristics of the stars and their planets may be incorrect. As a result of their studies into Kepler-14, the Kepler team suggested the implementation of a high-resolution imaging campaign to re-examine transiting planet hosts, an effort which would only require a modest amount of telescope time.
Characteristics
Kepler-14 is a binary star whose two components are separated by at least 280 distances between the Earth and SunAstronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
. The estimated 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 the Kepler-14 binary system is approximated at 2800 years The two stars are of nearly equal brightness, but the primary component is slightly brighter as seen from Earth. The primary star has an estimated mass of 1.51 times that of the Sun
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
, and the secondary has an estimated mass of 1.39 times the Sun's mass.
Because Kepler-14 is so close-knit as seen fron Earth, it was impossible for the discovery team to separate the two stars and analyze their characteristics as separate stars. The Kepler team analyzed their characteristics anyways under the assumption that Kepler-14 was a single star. Kepler-14 is a binary star whose two components are separated by at least 280 distances between the Earth and Sun
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
. The estimated 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 the Kepler-14 binary system is approximated at 2800 years The two stars are of nearly equal brightness, but the primary component is slightly brighter as seen from Earth. The primary star has an estimated mass of 1.51 times that of the Sun
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
, and the secondary has an estimated mass of 1.39 times the Sun's mass. The Kepler-14 system is 980 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 (3,196 light years) from Earth. It has an 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...
of 12.12, and thus cannot be seen with the unaided eye.
Because Kepler-14 is so close-knit as seen fron Earth, it was impossible for the discovery team to separate the two stars and analyze their characteristics as separate stars. The Kepler team analyzed their characteristics anyways under the assumption that Kepler-14 was a single star.
If Kepler-14 were a single star, it would be an F-type star with a mass of 1.512 times the Sun's, and a size that is 2.048 times the Sun's radius. As a single star, the 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 Kepler-14 would be 6395 K, much hotter than the Sun, and the star's iron content
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...
would be 0.12, or 132% the amount found in the Sun. Assuming that Kepler-14's two stars formed at about the same time, their gyrochronological age
Gyrochronological age
The gyrochronological age of a star is determined by using the rate at which the star spins to find its true age. The process of the star was presented by Søren Meibom, who used data collected by the Kepler spacecraft to present his findings in 2010 after he analyzed cluster NGC 6811....
s would be approximately 2.2 billion years.
Planetary system
Kepler-14b is a JupiterJupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
-like planet in the orbit of the primary star of Kepler-14. The planet is 8.4 times Jupiter's mass
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....
, the equivalent of 2670 times Earth's mass. The planet is slightly larger than Jupiter at 1.14 Jupiter radii The density of Kepler-14b is 7.1 grams/cm3, the second densest planet confirmed by the Kepler spacecraft after 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...
. Kepler-14b completes an orbit every 6.79 days with a slightly irregular orbit indicated its orbital 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...
of 0.035.