Optical Gravitational Lensing Experiment

The Optical Gravitational Lensing Experiment or OGLE is a Polish

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

astronomical

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

project based at the University of Warsaw

University of Warsaw

The University of Warsaw is the largest university in Poland and one of the most prestigious, ranked as best Polish university in 2010 and 2011...

that is chiefly concerned with discovering dark matter

Dark matter

In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

using the microlensing technique. Since the project began in 1992, it has discovered several 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...

s as a side benefit. The project is led by Professor

Professor

A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

Andrzej Udalski

Professor Andrzej Udalski, PhD is a Polish astronomer and director of the Astronomical Observatory of the University of Warsaw...

, who is a co-author of the discovery of OGLE-2005-BLG-390Lb

OGLE-2005-BLG-390Lb

OGLE-2005-BLG-390Lb is a 'super-Earth' extrasolar planet orbiting the star OGLE-2005-BLG-390L, which is situated 21,500 ± 3,300 light years away from Earth, near the center of the Milky Way galaxy...

.

The main targets of the experiment are the Magellanic Clouds

Magellanic Clouds

The two Magellanic Clouds are irregular dwarf galaxies visible in the southern hemisphere, which are members of our Local Group and are orbiting our Milky Way galaxy...

and the Galactic Bulge, because of the large number of intervening stars that can be used for microlensing during a stellar 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...

. Most of the observations have been taken at the Las Campanas Observatory

Las Campanas Observatory

Las Campanas Observatory is an astronomical observatory owned and operated by the Carnegie Institution for Science It was established in 1969 and remains the primary observing site of that institution. The headquarters is located in La Serena, Chile and the observatory is in the southern Atacama...

in Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. Cooperating institutions include Princeton University

Princeton University

Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....

and the Carnegie Institution.

The three phases of the project had already been concluded, OGLE-I (1992–1995), OGLE-II (1996–2000), and OGLE-III (2001–2009). OGLE-I was the project pilot phase; for OGLE-II, a 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...

was specially constructed, placed in Las Campanas Observatory and dedicated to the project. The 8-chip mosaic CCD camera was built in Poland and shipped to Chile. OGLE-III was primarily devoted to detecting gravitational microlensing

Gravitational 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 ...

events and transiting planets. As a byproduct of constant monitoring of hundreds of millions of stars, the largest catalogs of variable stars were constructed. The fields in four main directions where monitored during this phase: in the direction of the Galactic Bulge, the constellation 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:...

and toward both Large Magellanic Cloud

Large Magellanic Cloud

The Large Magellanic Cloud is a nearby irregular galaxy, and is a satellite of the Milky Way. At a distance of slightly less than 50 kiloparsecs , the LMC is the third closest galaxy to the Milky Way, with the Sagittarius Dwarf Spheroidal and Canis Major Dwarf Galaxy lying closer to the center...

and Small Magellanic Cloud

Small Magellanic Cloud

The Small Magellanic Cloud is a dwarf galaxy. It has a diameter of about 7,000 light-years and contains several hundred million stars. It has a total mass of approximately 7 billion times the mass of our Sun....

.
Also, first planets using the microlensing technique were detected during that phase. In 2010, following engineering work in 2009, the fourth phase, OGLE-IV, have been started using 32-chip mosaic CCD camera. The main goal for that phase is to increase the number of planetary detections using microlensing. The increased field of view of the new camera give the possibility for increased cadence of observations when keeping the monitored area of the sky at similar level.

Planets discovered

Fourteen planets have so far been discovered by the OGLE project. Eight of the planets were discovered by the transit method and six by the gravitational microlensing method.

Planets are shown in the order of discovery. Planets in multiple-planet systems are highlighted in yellow. Inclinations with + means orbit has at least that inclination.

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...	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....	App. mag. 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...	Distance (ly)	Spectral type Stellar classification In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...	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,...	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:... (M_J 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.... )	Radius Radius In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its... (R_J)	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... (d 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... )	Semi-major axis Semi-major axis The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape... (AU Astronomical unit An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance.... )	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...	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... (° Degree (angle) A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians... )	Discovery year
OGLE-TR-10 OGLE-TR-10 OGLE-TR-10 is a distant, magnitude 16 star in the constellation of Sagittarius. It is located near the Galactic Center.This star is listed as a eclipsing type variable star with the eclipse due to the passage of the planet as noted in the discovery papers.-Planetary system:This star is home to...	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...	15.78	5000	G2V	OGLE-TR-10 b OGLE-TR-10 b OGLE-TR-10b is an extrasolar planet orbiting the star OGLE-TR-10.The planet was first detected by the Optical Gravitational Lensing Experiment survey in 2002. The star, OGLE-TR-10, was seen dimming by a tiny amount every 3 days. The transit lightcurve resembles that of HD 209458 b, the first...	0.63	1.26	3.10129	0.04162	0	84.5	2002
OGLE-TR-111 OGLE-TR-111 OGLE-TR-111 is a yellow dwarf star approximately 5,000 light-years away in the constellation of Carina . Having an apparent magnitude of about 17 this distant and dim star has not yet been cataloged.- Planetary system :...	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:...	16.96	5000	G	OGLE-TR-111 b	0.53	1.0	4.01610	0.047	0	88.1	2002
OGLE-TR-132 OGLE-TR-132 OGLE-TR-132 is a distant magnitude 15.72 star in the star fields of the constellation Carina. Because of its great distance, about 4900 light years, and location in the crowded field it was not notable in any way...	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:...	15.72	7110	F	OGLE-TR-132 b	1.14	1.18	1.689868	0.0306	0	85	2003
OGLE-TR-56	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...	16.56	4892	G	OGLE-TR-56 b	1.29	1.30	1.211909	0.0225	0	78.8	2003
OGLE-TR-113 OGLE-TR-113 OGLE-TR-113 is a dim, distant magnitude 16 binary star in the star fields of the constellation Carina. Because of its distance of about 1800 light years, and location in a crowded field it was not notable in any way...	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:...	16.08	1800	K	OGLE-TR-113 b	1.32	1.09	1.4324757	0.0229	0	89.4	2004
OGLE-2003-BLG-235L /MOA-2003-BLG-53L	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...		19000	K	OGLE-2003-BLG-235Lb OGLE-2003-BLG-235Lb OGLE-2003-BLG-235Lb/MOA-2003-BLG-53Lb is an extrasolar planet discovered in April 2004 by the OGLE and MOA collaborations. Its high mass indicates that it is most probably a gas giant planet similar to Jupiter. It is located around 4.3 AU away from its parent star.- External links :***SPACE.com: ...	2.6			4.3			2004
OGLE-2005-BLG-071L OGLE-2005-BLG-071L OGLE-2005-BLG-071L is a distant, magnitude 19.5 galactic bulge star located in the constellation Scorpius, approximately 11000 light years away from the Solar System...	Scorpius Scorpius Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east...	19.5	9500	M	OGLE-2005-BLG-071Lb OGLE-2005-BLG-071Lb OGLE-2005-BLG-071Lb is an planet discovered by the Optical Gravitational Lensing Experiment and others in 2005, using gravitational microlensing. According to the best fit model, it has about 3.5 times the mass of Jupiter and a projected separation of 3.6 astronomical units from the star...	3.5		3600	3.6			2005
OGLE-2005-BLG-169L OGLE-2005-BLG-169L OGLE-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...	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...	19.4	8800	M?	OGLE-2005-BLG-169Lb OGLE-2005-BLG-169Lb OGLE-2005-BLG-169Lb is an extrasolar planet located approximately 2700 parsecs away in the constellation of Sagittarius, orbiting the star OGLE-2005-BLG-169L. This planet was discovered by the OGLE project using the gravitational microlensing method. Based on a most likely mass for the host star of...	0.041	0.345					2006
OGLE-2005-BLG-390L OGLE-2005-BLG-390L OGLE-2005-BLG-390L is a star thought to be a spectral type M - red dwarf star OGLE-2005-BLG-390L is a star thought to be a spectral type M - red dwarf star 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,...	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...		21500	M?	OGLE-2005-BLG-390Lb OGLE-2005-BLG-390Lb OGLE-2005-BLG-390Lb is a 'super-Earth' extrasolar planet orbiting the star OGLE-2005-BLG-390L, which is situated 21,500 ± 3,300 light years away from Earth, near the center of the Milky Way galaxy...	0.018						2006
OGLE-TR-211 OGLE-TR-211 OGLE-TR-211 is a distant magnitude 14 star located about 17,000 light years away in the constellation of Carina.-Planetary system:OGLE-TR-211 has a transiting planet in a very close orbit, another hot Jupiter....	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:...		5300	F	OGLE-TR-211 b	1.03	1.36	3.67724	0.051	0	87.2+	2007
OGLE-TR-182 OGLE-TR-182 OGLE-TR-182 is a dim magnitude 17 star far off in the constellation Carina at a distance of approximately 12,700 light years.-Planetary system:This star is home to the transiting extrasolar planet OGLE-TR-182b discovered in October 2007....	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:...	16.84	12700	G	OGLE-TR-182 b	1.01	1.13	3.9791	0.051	0	85.7	2007
OGLE2-TR-L9 OGLE2-TR-L9 OGLE2-TR-L9 is a magnitude 15 star in the constellation Carina at a distance of approximately 2,935 light years.-Planetary system:This star is home to the transiting extrasolar planet OGLE2-TR-L9b discovered in 2008....	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:...		2935	F3	OGLE2-TR-L9 b	4.5	1.61	2.4855335	0.0308			2008
OGLE-2006-BLG-109L OGLE-2006-BLG-109L OGLE-2006-BLG-109L is a dim magnitude 17 unclassified galactic bulge star approximately 4,920 light-years away in the constellation of Sagittarius.- Planetary system :...	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...		4900		OGLE-2006-BLG-109Lb	0.71		1825	2.3			2008
OGLE-2006-BLG-109L OGLE-2006-BLG-109L OGLE-2006-BLG-109L is a dim magnitude 17 unclassified galactic bulge star approximately 4,920 light-years away in the constellation of Sagittarius.- Planetary system :...	Sagittarius Sagittarius (constellation) Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...		4900		OGLE-2006-BLG-109Lc	0.27		5100	4.8	0.11	59	2008

Note. For events detected by the gravitational microlensing method, year stands for OGLE season, BLG means that an event detected is in the Galactic BuLGe, and the following 3-digit number is an ordinal number of microlensing event in that season. For events detected by the transit method TR stands for TRansit and the following 3-digit number is an ordinal number of transit event.

External links

OGLE Homepage in Warsaw, Poland
OGLE-IV sky coverage: OGLE-IV fields

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Planets discovered

See also

External links