Characteristics | |
---|---|
Apparent magnitude (K) | 22.3 |
Observation data Epoch J2000 Equinox J2000 | |
Constellation | Sagittarius [1] |
Right ascension | 18h 00m 23.48s [2] |
Declination | −31° 14′ 42.93″ [2] |
Astrometry | |
Distance | 24,400±3,000 ly (7,490±910 pc) [3] |
Details [3] | |
Mass | 0.193±0.029 M☉ |
Database references | |
SIMBAD | data |
MOA-2011-BLG-262L is a red dwarf with an orbiting exoplanet, both detected through the gravitational microlensing event MOA-2011-BLG-262. [3] It was once believed to be either an exoplanet with 3.2 times the mass of Jupiter and a exomoon with 0.47 times Earth's mass or a red dwarf with a mass of 0.11 solar masses orbited by a ~17 M🜨 planet, [2] [4] but the latter scenario was confirmed in 2024 based on observations of the host star by the Keck telescope, 10 years after the ending of the microlensing event. [3]
The system is located 24,400 light-years from Earth, in the constellation Sagittarius. [1] The host star is a red dwarf, with 19% the Sun's mass and a faint apparent magnitude of 22.3 in the K-band. It has a transverse velocity of 541.3±65.75 km/s , the highest ever found for any star with a known exoplanet. [3]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 28.92±4.75 M🜨 | 0.98+0.56 −0.20 | — | — | — | — |
A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. For example, the Sun together with the planetary system revolving around it, including Earth, form the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
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.
An exomoon or extrasolar moon is a natural satellite that orbits an exoplanet or other non-stellar extrasolar body.
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.
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.
MACHO-1997-BLG-41, commonly abbreviated as 97-BLG-41 or MACHO-97-BLG-41, was a gravitational microlensing event located in Sagittarius which occurred in July 1999. The source star is likely a giant or subgiant star of spectral type K located at a distance of around 8 kiloparsecs. The lens star is a binary system approximately 10,000 light-years away in the constellation Sagittarius. The two stars are separated from each other by about 0.9 AU and have an orbital period of around 1.5 years. The most likely mass of the system is about 0.3 times that of the Sun. Star A and star B are both red dwarfs.
OGLE-2005-BLG-071L is a distant, magnitude 19.5 galactic bulge star located in the constellation Scorpius, approximately 11,000 light years away from the Solar System. The star is probably a red dwarf with a mass 43% of that of the Sun.
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.
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.
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.
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).
MOA-2009-BLG-387L is a red dwarf in the Sagittarius constellation that is host to the planet MOA-2009-BLG-387Lb. The star is estimated to be nearly 20,000 light years away and approximately one fifth the mass of the Sun, although large confidence intervals exist, reflecting the uncertainties in both the mass and distance. The star drew the attention of astronomers when it became the lens of gravitational microlensing event MOA-2009-BLG-387L, in which it eclipsed a background star and created distorted caustics, an envelope of reflected or refracted light rays. Analysis of the caustic events and of follow-up observational data led to the planet's discovery, which was reported in February 2011.
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-2016-BLG-1195Lb is an extrasolar planet located about 22,000 light-years from Earth, in the galactic bulge, orbiting the 0.57±0.06 M☉ star OGLE-2016-BLG-1195L, discovered in 2017. The planet was detected using gravitational microlensing techniques managed by the Korea Astronomy and Space Science Institute and the Spitzer Space Telescope. Initially, it was believed the planet has a mass similar to Earth and is located about the same distance from its host star as the Earth is from the Sun, although it was expected to be much colder.
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.
KMT-2020-BLG-0414L is a white dwarf star about 4,000 light-years away in the constellation Sagittarius, which is orbited by an Earth-mass exoplanet and a brown dwarf.