Related Research Articles
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect. It can be used to detect objects that range 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 much light (stars) or large objects that block background light. These objects make up only a minor portion of the mass of a galaxy. Microlensing allows the study of objects that emit little or no light.
OGLE-2005-BLG-390Lb is a super-Earth exoplanet orbiting OGLE-2005-BLG-390L, a star 21,500 ± 3,300 light years from Earth near the center of the Milky Way. It is one of the most distant planets known. On 25 January 2006, Probing Lensing Anomalies NETwork/Robotic Telescope Network (PLANET/Robonet), Optical Gravitational Lensing Experiment (OGLE), and Microlensing Observations in Astrophysics (MOA) made a joint announcement of the discovery. The planet does not appear to meet conditions presumed necessary to support life.
OGLE-2005-BLG-390L is a star thought to be a spectral type M. This dim magnitude 16 galactic bulge star is located in the Scorpius constellation at a far distance of about 21,500 light years.
OGLE-2003-BLG-235/MOA 2003-BLG-53 was a gravitational microlensing event which occurred in the constellation of Sagittarius during July 2003. The event was observed both as part of the Optical Gravitational Lensing Experiment (OGLE) and by the Microlensing Observations in Astrophysics group (MOA), hence the double designation. The source star in the gravitational lens is a main sequence star of spectral type G located around 8.8 kiloparsecs away in the galactic bulge. The lens star is an orange dwarf star of spectral type K, which is accompanied by a giant planet.
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 0.49 solar mass (M☉), the planet has a mass of 13 times that of Earth (M⊕). Its mass and estimated temperature are close to those of Uranus. It is speculated that this planet may either be an ice giant like Uranus, or a "naked super-Earth" with a solid icy or rocky surface.
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. The star is probably a red dwarf with a mass 46% of that of our Sun.
OGLE-2006-BLG-109L is a dim magnitude 17 M0V galactic bulge star approximately 4,920 light-years away in the constellation of Scorpius.
RoboNet-1.0 was a prototype global network of UK-built 2-metre robotic telescopes, the largest of their kind in the world, comprising the Liverpool Telescope on La Palma, the Faulkes Telescope North on Maui (Hawaii), and the Faulkes Telescope South in Australia, managed by a consortium of ten UK universities under the lead of Liverpool John Moores University. For the technological aims of integrating a global network to act effectively as a single instrument, and maximizing the scientific return by applying the newest developments in e-Science, RoboNet adopted the intelligent-agent architecture devised and maintained by the eSTAR project.
OGLE-2006-BLG-109Lc is an extrasolar planet approximately 4,920 light-years away in the constellation of Sagittarius. The planet was detected orbiting the star OGLE-2006-BLG-109L in 2008 by a research team using Microlensing. The host star is about 50% the mass of the Sun and the planet is about 90% the mass of Saturn.
OGLE-2005-BLG-071Lb is a planet discovered by the Optical Gravitational Lensing Experiment (OGLE) 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. This would result in an effective temperature around 50 K, similar to that of Neptune. However, an alternative model which gives a slightly lower mass of 3.3 times that of Jupiter and a projected separation of 2.1 AU is only slightly less likely. It may be the most massive planet currently known around a red dwarf star.
MOA-2007-BLG-192L is a low-mass red dwarf star or brown dwarf, approximately 3,000 light-years away in the constellation of Sagittarius. It is estimated to have a mass approximately 6% of the Sun's. In 2008, an Earth-sized extrasolar planet was announced to be orbiting this object.
MOA-2008-BLG-310L is a 23rd magnitude star located at least 20000 light years away in the constellation Scorpius. This star has mass 0.67 solar masses which imply that it could probably be a late K-type star. In 2009 during the microlensing event, a planet was found orbiting this star at a distance of 1.25 AU and has mass 0.23 times that of Jupiter.
MOA-2008-BLG-310Lb is an extrasolar planet which orbits probably the late K-type star MOA-2008-BLG-310L, located at least 20000 light years away in the constellation Scorpius. This planet has mass 23% of Jupiter or 77% of Saturn and orbits at 1.25 AU from the star. This planet was discovered by using the gravitational microlensing method on August 4, 2009. As it is typical for exoplanets detected by microlensing method, the orbital period and eccentricity are not determined.
OGLE-2007-BLG-368Lb is an extrasolar planet located approximately 19,230 light-years away in the constellation of Scorpius, orbiting the star OGLE-2007-BLG-368L. This planet was detected on December 8, 2009 by the gravitational microlensing by Sumi. It has mass 6.94% of Jupiter and is located 3.3 AU from the star when observed. Based on those properties it would classify as a Cold Neptune. It is the second Cold Neptune to be observed, the first being OGLE-2005-BLG-169Lb. This planet is most likely be similar to Uranus and Neptune in the solar system in terms of atmospheric and internal properties.
The Microlensing Follow-Up Network is an informal group of observers who monitor high magnification gravitational microlensing events in the Milky Way's Galactic Bulge. Its goal is to detect extrasolar planets via microlensing of the parent star by the planet. μFUN is a follow-up network - they monitor microlensing events identified by survey groups such as OGLE and Microlensing Observations in Astrophysics (MOA).
OGLE-2014-BLG-0124Lb is one of the farthest planets that we know of today. It is approximately 13,000 light years away, located near the center of the galaxy. The planet was discovered using a technique called microlensing. In this case it took 150 days. Two telescopes are used to detect the planet and the time difference between identification by each telescope is used to calculate the distance to the planet. This also contributes to determining the mass of the planet which is about half of Jupiter's. The planet orbits a star with a mass of 0.7 solar masses and is 3.1 AUs from it.
OGLE-2007-BLG-349(AB)b is a circumbinary extrasolar planet about 8,000 light-years away in the constellation of Sagittarius. It is the first circumbinary exoplanet to be discovered using the microlensing method of detecting exoplanets.
OGLE-2016-BLG-1195Lb is an extrasolar planet located nearly 13,000 light-years from Earth, orbiting the star OGLE-2016-BLG-1195L, which is only 7.8 percent the size of the Sun. This planet was detected in 2017 using gravitational microlensing techniques managed by the Korea Astronomy and Space Science Institute and the Spitzer Space Telescope. It has a mass similar to Earth and is located about the same distance from its host star as the Earth is from the Sun. However, the host star is so small that it may not be a star at all. It may be "a brown dwarf or an ultracool dwarf" instead, so the planet is likely far too cold to be habitable. Based on its currently observed properties, the 'iceball' planet may be described as a very cold Earth-like exoplanet.
OGLE-2016-BLG-1190Lb is an extremely massive exoplanet, with a mass about 13.4 times that of Jupiter (MJ), or is, possibly, a low mass brown dwarf, orbiting the G-dwarf star OGLE-2016-BLG-1190L, located about 22,000 light years from Earth, in the constellation of Sagittarius, in the galactic bulge of the Milky Way.
References
- ↑ Gaudi, B. S.; et al. (2008). "Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing". Science . 319 (5865): 927–930. arXiv: 0802.1920 . Bibcode:2008Sci...319..927G. doi:10.1126/science.1151947. PMID 18276883. S2CID 119281787. web preprint
