OGLE-TR-111
Encyclopedia
OGLE-TR-111 is a yellow dwarf
star approximately 5,000 light-year
s away in the constellation
of Carina
(the Keel
). Having an apparent magnitude
of about 17 this distant and dim star has not yet been cataloged.
(OGLE) survey detected that the light from the star periodically dimmed very slightly every 4 day
s, indicating a planet
-sized body transit
ing the star. But since the mass of the object had not been measured, it was not clear that it was a true planet, low-mass red dwarf
or something else.
In 2004 radial velocity
measurements showed unambiguously that the transiting body is indeed a planet.
The planet is probably very similar to the other "hot Jupiter
s" orbiting nearby stars. Its mass is about half that of Jupiter
and it orbits the star at a distance less than 1/20th that of Earth
from the Sun
.
In 2005, evidence of another transit was announced. Planet "OGLE-TR-111c" is a possible extrasolar planet
orbiting the star. It was first proposed in 2005 based on preliminary evidence from the Optical Gravitational Lensing Experiment
(OGLE) survey. More data is required to confirm this planet candidate. If it is confirmed, OGLE-TR-111 would become one of the first stars with a pair of transiting planets
.
Yellow dwarf
A G-type main-sequence star , often called a yellow dwarf, is a main-sequence star of spectral type G and luminosity class V. Such a star has about 0.8 to 1.2 solar masses and surface temperature of between 5,300 and 6,000 K., Tables VII, VIII...
star approximately 5,000 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 Carina
Carina (constellation)
Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was formerly part of the larger constellation of Argo Navis until that constellation was divided in three.-Stars:...
(the Keel
Keel
In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...
). Having 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 about 17 this distant and dim star has not yet been cataloged.
Planetary system
In 2002 the Optical Gravitational Lensing ExperimentOptical Gravitational Lensing Experiment
The 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) survey detected that the light from the star periodically dimmed very slightly every 4 day
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...
s, indicating a planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
-sized body transit
Astronomical transit
The term transit or astronomical transit has three meanings in astronomy:* A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point...
ing the star. But since the mass of the object had not been measured, it was not clear that it was a true planet, low-mass red dwarf
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....
or something else.
In 2004 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 showed unambiguously that the transiting body is indeed a planet.
The planet is probably very similar to the other "hot Jupiter
Hot Jupiter
Hot Jupiters are a class of extrasolar planet whose mass is close to or exceeds that of Jupiter...
s" orbiting nearby stars. Its mass is about half that of 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,...
and it orbits the star at a distance less than 1/20th that of 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...
from the Sun
Sun
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...
.
In 2005, evidence of another transit was announced. Planet "OGLE-TR-111c" is a possible extrasolar planet
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...
orbiting the star. It was first proposed in 2005 based on preliminary evidence from the Optical Gravitational Lensing Experiment
Optical Gravitational Lensing Experiment
The 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) survey. More data is required to confirm this planet candidate. If it is confirmed, OGLE-TR-111 would become one of the first stars with a pair of transiting planets
Astronomical transit
The term transit or astronomical transit has three meanings in astronomy:* A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point...
.