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A rogue black hole (also termed a free-floating, nomad, orphan, unbound or wandering black hole) is an interstellar or intergalactic black hole. [2]
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A rogue black hole (also termed a free-floating, nomad, orphan, unbound or wandering black hole) is an interstellar or intergalactic black hole. [2]
These are objects without a host galactic group, caused by collisions between two galaxies or when the merging of two black holes is disrupted. It has been estimated that there could be 12 rogue supermassive black holes on the edge of the Milky Way galaxy. [3]
In January 2022, a team of astronomers reported of OGLE-2011-BLG-0462/MOA-2011-BLG-191, the first unambiguous detection and mass measurement of an isolated stellar black hole using the Hubble Space Telescope together with the Microlensing Observations in Astrophysics (MOA) and the Optical Gravitational Lensing Experiment (OGLE). [4] [1] [5] This black hole is located 5,000 light-years away, has a mass 7.1 times that of the Sun, and moves at about 45 km/s. [6] While there have been other candidates, they have been detected more indirectly. [7]
A gravitational lens is matter, such as a cluster of galaxies or a point particle, that bends light from a distant source as it travels toward an observer. The amount of gravitational lensing is described by Albert Einstein's general theory of relativity. If light is treated as corpuscles travelling at the speed of light, Newtonian physics also predicts the bending of light, but only half of that predicted by general relativity.
A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf.
Gravitational microlensing is an astronomical phenomenon caused by 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, making it one of the most distant planets known. On January 25, 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.
The Optical Gravitational Lensing Experiment (OGLE) is a Polish astronomical project based at the University of Warsaw that runs a long-term variability sky survey (1992–present). The main goals are the detection and classification of variable stars, discovery of microlensing events, dwarf novae, and studies of the structure of the Galaxy and the Magellanic Clouds. Since the project began in 1992, it has discovered a multitude of extrasolar planets, together with the first planet discovered using the transit method (OGLE-TR-56b) and gravitational microlensing. The project has been led by professor Andrzej Udalski since its inception.
Microlensing Observations in Astrophysics (MOA) is a collaborative project between researchers in New Zealand and Japan, led by Professor Yasushi Muraki of Nagoya University. They use microlensing to observe dark matter, extra-solar planets, and stellar atmospheres from the Southern Hemisphere. The group concentrates especially on the detection and observation of gravitational microlensing events of high magnification, of order 100 or more, as these provide the greatest sensitivity to extrasolar planets. They work with other groups in Australia, the United States and elsewhere. Observations are conducted at New Zealand's Mt. John University Observatory using a 1.8 m (70.9 in) reflector telescope built for the project.
OGLE-2003-BLG-235L (MOA-2003-BLG-53L) is a star in the constellation of Sagittarius. The first gravitational microlensing event for which a planet orbiting the lens was detected around this star. The event occurred in during July 2003. Two groups observed and independently detected the event: the Optical Gravitational Lensing Experiment (OGLE) and the Microlensing Observations in Astrophysics (MOA), hence, the double designation. It is an orange dwarf star of spectral type K, which is accompanied by a giant planet.
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.
MOA-2007-BLG-192Lb, occasionally shortened to MOA-192 b, is an extrasolar planet approximately 7,000 light-years away in the constellation of Sagittarius. The planet was discovered orbiting the low-mass star MOA-2007-BLG-192L. It was found when it caused a gravitational microlensing event on May 24, 2007, which was detected as part of the MOA-II microlensing survey at the Mount John University Observatory in New Zealand.
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.
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).
An intergalactic star, also known as an intracluster star or a rogue star, is a star not gravitationally bound to any galaxy. Although a source of much discussion in the scientific community during the late 1990s, intergalactic stars are now generally thought to have originated in galaxies, like other stars, before being expelled as the result of either galaxies colliding or of a multiple-star system traveling too close to a supermassive black hole, which are found at the center of many galaxies.
MOA-2010-BLG-477L is a star whose existence was detected when it caused a microlensing event in August, 2010. The microlensing event also revealed the existence of a planet orbiting the star. At first the star was thought to be about 0.67 times the mass of the Sun, in the main-sequence phase of its stellar evolution. But by the time the star should have been separated enough in the sky from the source star of the microlensing event it was not detected, implying that it is actually a dim white dwarf star.
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-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.
OGLE-2011-BLG-0462, also known as MOA-2011-BLG-191, is a stellar-mass black hole isolated in interstellar space. OGLE-2011-BLG-0462 lies at a distance of 1,720 parsecs in the direction of the galactic bulge in the constellation Sagittarius. The black hole has a mass of about 6.03 M☉. OGLE-2011-BLG-0462 is the first truly isolated black hole which has been confirmed.
