WASP-24
Encyclopedia
WASP-24 is an F-type star with the Hot Jupiter
planet WASP-24b
in orbit. WASP-24 is slightly larger and more massive than the Sun, but is more metal-rich and hotter than the Sun. However, it is probably not a part of the main sequence
, as seen in its young age. WASP-24 was first observed by the SuperWASP
planet-searching organization, which flagged it as a potential host to a planet before following up with radial velocity
and spectral measurements. Analysis of these confirmed the planetary nature of WASP-24b, which was later released to the public on the SuperWASP website.
Consortium observed the night sky in WASP-24's vicinity. The star, in particular, was flagged as a host to a planetary candidate. After accumulating over 9,750 datapoints for a light curve on WASP-24, all information on the star that had been previously catalogued was collected alongside the new data, and the star was set aside for manual follow-up observations.
The 2.56m Nordic Optical Telescope
(NOT) at the Canary Islands' Roque de los Muchachos Observatory
was used to collected radial velocity
measurements. The Fibre-Fed Echelle Spectrograph, or FIES, was the instrument that collected these observations between December 2008 and April 2009; also used was the CORALIE spectrograph
on the Leonhard Euler Telescope
at Chile's La Silla Observatory
, which collected additional radial velocity and spectral measurements. Analysis of WASP-24's spectrum ruled out the possibility that WASP-24 is a rapidly rotating star, which could make confirmation of a planet difficult, or that it is a spectroscopic binary star system. Use of a span bisector analysis revealed that the star is not very active. WASP-24 was then observed using Hawaii's Faulkes Telescope North
and Australia's Faulkes Telescope South
, searching for a period at which the discovered planet WASP-24b
might transit, or cross in front of, its star, over various days in 2009 and 2010.
Using information collected by NOT, WASP-24's temperature, metallicity, and other characteristics were derived. Detected levels of lithium
and the star's surface gravity suggests that the star does not follow the main sequence
. These stellar characteristics were later used to derive its planet's characteristics.
WASP-24 and, specifically, the discovery of orbiting Hot Jupiter
WASP-24b were first reported on SuperWASP's website.
s, or 1,076 light years, away. With an apparent magnitude
of 11.3, the star is invisible to the naked eye
from the Earth's perspective. WASP-24 is 1.129 solar mass
es and 1.147 solar radii, making it just slightly larger and more massive than the Sun. However, it is hotter, with an effective temperature
of 6075 K. The star has a metallicity
of [M/H] = 0.07, which means that it has 1.17 times the amount of metals (elements heavier than He) than what is found in the Sun. The best fit for WASP-24's age is 1.6 billion years, although this is not well-constrained, and its actual age may lie anywhere between 0 and 3.7 billion years.
The star's surface gravity, logg = 4.15, and its low levels of lithium helped derive the star's age, and revealed that it most likely evolved away from the main sequence
.
es and 1.104 Jupiter radii. Thus, the planet is slightly larger and slightly more massive than Jupiter is. WASP-24b orbits at a distance of 0.0359 AU
, roughly 3.5% of the mean distance between the Earth and Sun. It is the only planet yet discovered in WASP-24's orbit.
Hot Jupiter
Hot Jupiters are a class of extrasolar planet whose mass is close to or exceeds that of Jupiter...
planet WASP-24b
WASP-24b
WASP-24b is a Hot Jupiter detected in the orbit of the F-type star WASP-24. The planet is approximately the same size and mass of Jupiter, but it orbits at approximately 4% of the mean distance between the Earth and the Sun every two days...
in orbit. WASP-24 is slightly larger and more massive than the Sun, but is more metal-rich and hotter than the Sun. However, it is probably not a part of the main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
, as seen in its young age. WASP-24 was first observed by the SuperWASP
SuperWASP
SuperWASP is an international academic organisation performing an ultra-wide angle search for transiting extrasolar planets with the aim of covering the entire sky down to ~15th magnitude.-Equipment:...
planet-searching organization, which flagged it as a potential host to a planet before following up with 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...
and spectral measurements. Analysis of these confirmed the planetary nature of WASP-24b, which was later released to the public on the SuperWASP website.
Observational history
Between March 2008 and April 2009, the northern and southern portions of the SuperWASPSuperWASP
SuperWASP is an international academic organisation performing an ultra-wide angle search for transiting extrasolar planets with the aim of covering the entire sky down to ~15th magnitude.-Equipment:...
Consortium observed the night sky in WASP-24's vicinity. The star, in particular, was flagged as a host to a planetary candidate. After accumulating over 9,750 datapoints for a light curve on WASP-24, all information on the star that had been previously catalogued was collected alongside the new data, and the star was set aside for manual follow-up observations.
The 2.56m 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...
(NOT) at the Canary Islands' Roque de los Muchachos Observatory
Roque de los Muchachos Observatory
Roque de los Muchachos Observatory is an astronomical observatory located in the municipality of Garafía on the island of La Palma in the Canary Islands...
was used to collected 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...
measurements. The Fibre-Fed Echelle Spectrograph, or FIES, was the instrument that collected these observations between December 2008 and April 2009; also used was the CORALIE spectrograph
CORALIE spectrograph
The CORALIE spectrograph is an echelle type spectrograph used for astronomy. This instrument used with a telescope to measure star spectra for the Doppler effect to detect the presence of extrasolar planets by the radial velocity method...
on the Leonhard Euler Telescope
Leonhard Euler Telescope
Leonhard Euler Telescope, or Swiss 1.2-m Leonhard Euler Telescope, is a diameter aperture reflecting telescope at the Geneva Observatory at La Silla Observatory. It is use for astronomy, and runs the CORALIE echelle spectrograph to search for planets. Its first planet discovery was of one in orbit...
at Chile's La Silla Observatory
La Silla Observatory
La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory organisation, and several others are partly maintained by ESO...
, which collected additional radial velocity and spectral measurements. Analysis of WASP-24's spectrum ruled out the possibility that WASP-24 is a rapidly rotating star, which could make confirmation of a planet difficult, or that it is a spectroscopic binary star system. Use of a span bisector analysis revealed that the star is not very active. WASP-24 was then observed using Hawaii's Faulkes Telescope North
Faulkes Telescope North
The Faulkes Telescope North is a clone of the Liverpool Telescope, and is located at Haleakala Observatory in the U.S. state of Hawaii.The telescope is owned and operated by LCOGT. This telescope and its sister telescope Faulkes Telescope South are used by research and education groups across the...
and Australia's Faulkes Telescope South
Faulkes Telescope South
The Faulkes Telescope South is a clone of the Liverpool Telescope and is located at Siding Spring Observatory. It is a Ritchey-Chrétien telescope....
, searching for a period at which the discovered planet WASP-24b
WASP-24b
WASP-24b is a Hot Jupiter detected in the orbit of the F-type star WASP-24. The planet is approximately the same size and mass of Jupiter, but it orbits at approximately 4% of the mean distance between the Earth and the Sun every two days...
might transit, or cross in front of, its star, over various days in 2009 and 2010.
Using information collected by NOT, WASP-24's temperature, metallicity, and other characteristics were derived. Detected levels of lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
and the star's surface gravity suggests that the star does not follow the main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
. These stellar characteristics were later used to derive its planet's characteristics.
WASP-24 and, specifically, the discovery of orbiting Hot Jupiter
Hot Jupiter
Hot Jupiters are a class of extrasolar planet whose mass is close to or exceeds that of Jupiter...
WASP-24b were first reported on SuperWASP's website.
Characteristics
WASP-24 is an F-type star that lies 330 parsecParsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
s, or 1,076 light years, away. With 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 11.3, the star is invisible to 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"...
from the Earth's perspective. WASP-24 is 1.129 solar mass
Solar mass
The solar mass , , is a standard unit of mass in astronomy, used to indicate the masses of other stars and galaxies...
es and 1.147 solar radii, making it just slightly larger and more massive than the Sun. However, it is hotter, with 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 6075 K. The star has a 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 [M/H] = 0.07, which means that it has 1.17 times the amount of metals (elements heavier than He) than what is found in the Sun. The best fit for WASP-24's age is 1.6 billion years, although this is not well-constrained, and its actual age may lie anywhere between 0 and 3.7 billion years.
The star's surface gravity, logg = 4.15, and its low levels of lithium helped derive the star's age, and revealed that it most likely evolved away from the main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
.
Planetary system
WASP-24b is a Hot Jupiter that is 1.032 Jupiter massJupiter 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....
es and 1.104 Jupiter radii. Thus, the planet is slightly larger and slightly more massive than Jupiter is. WASP-24b orbits at a distance of 0.0359 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
, roughly 3.5% of the mean distance between the Earth and Sun. It is the only planet yet discovered in WASP-24's orbit.