14 Herculis b
Encyclopedia
14 Herculis b or 14 Her b is an extrasolar planet
approximately 59 light-year
s away in the constellation
of Hercules
. The planet was found orbiting the star
14 Herculis
, with a mass that would likely make the planet a Jovian planet roughly the same size as Jupiter
but much more massive. It was discovered in July 1998 by the Geneva Extrasolar Planet Search
team. At the time of discovery was the extrasolar planet with the longest orbit
al period, though longer-period planets have subsequently been discovered.
satellite suggest that this planet has an orbital inclination
of 155.3° with respect to plane of the sky, which would imply a true mass
of 11.1 times that of Jupiter, close to the deuterium burning
threshold that some astronomers use to define the distinction between a planet and a brown dwarf
. However subsequent analysis suggests that the Hipparcos measurements were not precise enough to accurately determine the orbits, so the actual inclination and true mass of the planet remains unknown. Its inclination is being calculated via astrometry with Hubble. The astrometricians expect publication by mid 2009. It may also be targeted by future astrometric missions such as Gaia
and the Space Interferometry Mission
.
CFHT 3.60m telescope
on Mauna Kea
did not make such a detection, confirming the object is not a star.
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
approximately 59 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Hercules
Hercules (constellation)
Hercules is a constellation named after Hercules, the Roman mythological hero adapted from the Greek hero Heracles. Hercules was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations today...
. The planet was found orbiting the star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
14 Herculis
14 Herculis
14 Herculis or 14 Her is an orange dwarf star approximately 59 light-years away in the constellation Hercules. Because of its apparent magnitude, the star cannot be seen with the naked eye...
, with a mass that would likely make the planet a Jovian planet roughly the same size as Jupiter
Jupiter
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,...
but much more massive. It was discovered in July 1998 by the Geneva Extrasolar Planet Search
Geneva Extrasolar Planet Search
The Geneva Extrasolar Planet Search is a variety of observational programs run by M. Mayor, D. Naef, F. Pepe, D. Queloz, N.C. Santos, and S. Udry. The program is located at the site of Sauverny in Versoix, a small town near Geneva, Switzerland...
team. At the time of discovery was the extrasolar planet with the longest orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
al period, though longer-period planets have subsequently been discovered.
Discovery
Like the majority of known extrasolar planets, 14 Herculis b was detected by measuring variations in its star's radial velocity as a result of the planet's gravity. This was done by making precise measurements of the Doppler shift of the spectrum of 14 Herculis. Prior to this analysis, another possible explanation of previous Doppler shift analysis included face-on spectroscopic binaries.Orbit and mass
Preliminary astrometric measurements made by the HipparcosHipparcos
Hipparcos was a scientific mission of the European Space Agency , launched in 1989 and operated between 1989 and 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky...
satellite suggest that this planet has an orbital inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
of 155.3° with respect to plane of the sky, which would imply a true mass
True mass
The term true mass is synonymous with the term mass, but is used in astronomy to differentiate the measured mass of a planet from the lower limit of mass usually obtained from radial velocity techniques...
of 11.1 times that of Jupiter, close to the deuterium burning
Deuterium burning
Deuterium burning is a nuclear fusion reaction that occurs in stars and some substellar objects, in which a deuterium nucleus and a proton combine to form a helium-3 nucleus...
threshold that some astronomers use to define the distinction between a planet and a brown dwarf
Brown dwarf
Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth...
. However subsequent analysis suggests that the Hipparcos measurements were not precise enough to accurately determine the orbits, so the actual inclination and true mass of the planet remains unknown. Its inclination is being calculated via astrometry with Hubble. The astrometricians expect publication by mid 2009. It may also be targeted by future astrometric missions such as Gaia
Gaia probe
Gaia is a European Space Agency astrometry space mission, and a successor to the ESA Hipparcos mission. It was included within the context of the ESA Horizon 2000 Plus long-term scientific programme in 2000. Arianespace expects to launch Gaia for the ESA in March 2013, using a Soyuz rocket from...
and the Space Interferometry Mission
Space Interferometry Mission
The Space Interferometry Mission, or SIM, also known as SIM Lite , was a planned space telescope developed by the U.S. National Aeronautics and Space Administration , in conjunction with contractor Northrop Grumman...
.
Direct imaging
Because of the wide separation between this planet and its host star, and the proximity of the 14 Herculis system to the Sun, it is a promising candidate for direct imaging of the planet, as the angular separation of the planet and host star will be large enough that the light from the planet and star might be spatially resolved. However, a search made using the adaptive opticsAdaptive 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...
CFHT 3.60m telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
on Mauna Kea
Mauna Kea
Mauna Kea is a volcano on the island of Hawaii. Standing above sea level, its peak is the highest point in the state of Hawaii. However, much of the mountain is under water; when measured from its oceanic base, Mauna Kea is over tall—significantly taller than Mount Everest...
did not make such a detection, confirming the object is not a star.