OGLE-2005-BLG-390L
Encyclopedia
OGLE-2005-BLG-390L is a star thought to be a spectral type M - red dwarf
star (95% probability, 4% probability it is a white dwarf
, <1% probability it is a neutron star
or black hole
). This dim magnitude
16 galactic bulge star
is located in the Scorpius constellation
at the far distance of about 21,500 light years.
. Indications is that the planet is about five times Earth
mass, orbiting at about 2.6 astronomical unit
s from the parent star. The discovery was announced on January 25, 2006.
OGLE-2005-BLG-390Lb is considered one of the smallest known extrasolar planets around a main sequence
star, possibly rocky, with a mass
around 5.5 times that of the Earth. The orbital
radius (assuming a circular orbit) of the planet is 2.6 AU
, however the orbital elements are unknown. Based on its low mass and estimated temperature of around 50 K
, the planet is thought to consist mainly of ices, like Pluto
or Uranus
, rather than being a Jupiter
-like gas giant
.
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
star (95% probability, 4% probability it is a white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
, <1% probability it is a neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
or black hole
Black hole
A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
). This dim 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...
16 galactic bulge 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...
is located in the Scorpius 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....
at the far distance of about 21,500 light years.
Planetary system
OGLE-2005-BLG-390L has one known planet, which was discovered using the technique of gravitational microlensingGravitational microlensing
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects ranging from the mass of a planet to the mass of a star, regardless of the light they emit. Typically, astronomers can only detect bright objects that emit lots of light ...
. Indications is that the planet is about five times 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...
mass, orbiting at about 2.6 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s from the parent star. The discovery was announced on January 25, 2006.
OGLE-2005-BLG-390Lb is considered one of the smallest known extrasolar planets around a 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...
star, possibly rocky, with a mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
around 5.5 times that of the Earth. The orbital
radius (assuming a circular orbit) of the planet is 2.6 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
, however the orbital elements are unknown. Based on its low mass and estimated temperature of around 50 K
Kelvin
The kelvin is a unit of measurement for temperature. It is one of the seven base units in the International System of Units and is assigned the unit symbol K. The Kelvin scale is an absolute, thermodynamic temperature scale using as its null point absolute zero, the temperature at which all...
, the planet is thought to consist mainly of ices, like Pluto
Pluto
Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
or Uranus
Uranus
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...
, rather than being a 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,...
-like gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...
.
See also
- List of stars with extrasolar planets
- OGLE-2005-BLG-169LOGLE-2005-BLG-169LOGLE-2005-BLG-169L is a dim and distant magnitude 20 galactic bulge star located about 2,700 parsecs away in the constellation Sagittarius. If it is a main sequence star, then it is most likely a red dwarf with about half of the mass of the Sun...
- Optical Gravitational Lensing ExperimentOptical Gravitational Lensing ExperimentThe Optical Gravitational Lensing Experiment or OGLE is a Polish astronomical project based at the University of Warsaw that is chiefly concerned with discovering dark matter using the microlensing technique. Since the project began in 1992, it has discovered several extrasolar planets as a side...
(OGLE)