| Observatory code | 200  |
|---|---|
| Location | Beersel, Belgium |
| Coordinates | 50°45′37″N4°18′13″E / 50.7602°N 4.3036°E Coordinates: 50°45′37″N4°18′13″E / 50.7602°N 4.3036°E |
| Website | users |
  Location of Beersel Hills Observatory | |
Beersel Hills Observatory is an amateur astronomical observatory. Founded in April 1998, it is located near Beersel, Belgium. It is primarily dedicated to the study of variable stars and visual double stars, including Delta Scuti, eclipsing binaries, and visual double stars.
A binary star is a star system consisting of two stars orbiting around their common barycenter. Systems of two or more stars are called multiple star systems. These systems, especially when more distant, often appear to the unaided eye as a single point of light, and are then revealed as multiple by other means.
Albireo is a double star designated Beta Cygni. The International Astronomical Union uses the name "Albireo" specifically for the brightest star in the system. Although designated 'beta', it is fainter than Gamma Cygni, Delta Cygni, and Epsilon Cygni and is the fifth-brightest point of light in the constellation of Cygnus. Appearing to the naked eye to be a single star of magnitude 3, viewing through even a low-magnification telescope resolves it into its two components. The brighter yellow star, itself a very close binary system, makes a striking colour contrast with its fainter blue companion.
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.
Pictor is a constellation in the Southern Celestial Hemisphere, located between the star Canopus and the Large Magellanic Cloud. Its name is Latin for painter, and is an abbreviation of the older name Equuleus Pictoris. Normally represented as an easel, Pictor was named by Abbé Nicolas-Louis de Lacaille in the 18th century. The constellation's brightest star is Alpha Pictoris, a white main-sequence star around 97 light-years away from Earth. Pictor also hosts RR Pictoris, a cataclysmic variable star system that flared up as a nova, reaching apparent (visual) magnitude 1.2 in 1925 before fading into obscurity.
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies.
Robert Thorburn Ayton Innes FRSE FRAS was a Scottish astronomer best known for discovering Proxima Centauri in 1915, and numerous binary stars. He was also the first astronomer to have seen the Great January Comet of 1910, on 12 January. He was the founding director of a meteorological observatory in Johannesburg, which was later converted to an astronomical observatory and renamed to Union Observatory. He was the first Union Astronomer. Innes House, designed by Herbert Baker, built as his residence at the observatory, today houses the South African Institute of Electrical Engineers.
George A. Van Biesbroeck was a Belgian–American astronomer. He worked at observatories in Belgium, Germany and the United States. He specialized in the observation of double stars, asteroids and comets. He is notable for his long career as an observational astronomer.
Willem Hendrik van den Bos was a Dutch astronomer who worked at the Union Observatory in South Africa and became its director in 1941. He discovered nearly 3000 new double stars, made more than 71000 astronomical measurements and compiled a catalogue of Southern hemisphere double stars. He computed the orbits of more than 100 double stars using a method he invented and which later became the accepted standard.
Alpha Andromedae, officially named Alpheratz, is located 97 light-years from the Sun and is the brightest star in the constellation of Andromeda. Located immediately northeast of the constellation of Pegasus, it is the upper left star of the Great Square of Pegasus.
Alpha Comae Berenices is a binary star in the constellation of Coma Berenices, 17.8 parsecs (58 ly) away. It consists of two main sequence stars, each a little hotter and more luminous than the Sun.
Brooks Astronomical Observatory is an astronomical observatory owned and operated by Central Michigan University. It is located in Mount Pleasant, Michigan (USA). The observatory was established in 1964 and is located on the roof of the Brooks Hall science building. Both the building and observatory are named for Kendall P. Brooks, instructor of astronomy and other subjects in the period of 1910-1947.
The Carnegie telescope is a twin 20-inch (510 mm) refractor telescope located at Lick Observatory in California, United States. The double telescope's construction began in the 1930s with a grant from the Carnegie institution, although it was not completed until the 1960s when a second lens was added. The telescope is not designed for visual observation, rather it has two lenses used for taking photographs for a specific wavelength recorded on a film emulsion. It was used for photographic sky surveys in the late 20th century, which were successfully completed.
James Dunlop FRSE was a Scottish astronomer, noted for his work in Australia. He was employed by Sir Thomas Brisbane to work as astronomer's assistant at his private observatory, once located at Paramatta, New South Wales, about 23 kilometres (14 mi) west of Sydney during the 1820s and 1830s. Dunlop was mostly a visual observer, doing stellar astrometry work for Brisbane, and after its completion, then independently discovered and catalogued many new telescopic southern double stars and deep-sky objects. He later became the Superintendent of Paramatta Observatory when it was finally sold to the New South Wales Government.
The Royal Observatory of Belgium, has been situated in the Uccle municipality of Brussels (Belgium) since 1890. It was first established in Saint-Josse-ten-Noode in 1826 by William I under the impulse of Adolphe Quetelet. It was home to a 100 cm (39 in) diameter aperture Zeiss reflector in the first half of the 20th century, one of the largest telescopes in the world at the time. It owns a variety of other astronomical instruments, such as astrographs, as well as a range of seismograph equipment.
The University of Illinois Astronomical Observatory, located at 901 S. Mathews Avenue in Urbana, Illinois, on the campus of the University of Illinois Urbana-Champaign, was built in 1896, and was designed by Charles A. Gunn. It has been listed on the National Register of Historic Places since November 6, 1986, and on December 20, 1989, was designated a National Historic Landmark.
The Kenwood Astrophysical Observatory was the personal observatory of George Ellery Hale, constructed by his father, William E. Hale, in 1890 at the family home in the Kenwood section of Chicago. It was here that the spectroheliograph, which Hale had invented while attending MIT, was first put to practical use; and it was here that Hale established the Astrophysical Journal. Kenwood's principal instrument was a twelve-inch refractor, which was used in conjunction with a Rowland grating as part of the spectroheliograph. Hale hired Ferdinand Ellerman as an assistant; years later, the two would work together again at the Mount Wilson Observatory.
Alpha Doradus, Latinized from α Doradus, is the brightest star in the southern constellation of Dorado. The distance to this system, as measured using the parallax method, is about 169 light-years.
HD 125040 is a visual binary star in the northern constellation Boötes. The pair orbit each other with a semi-major axis of 105 astronomical units and a period of roughly 750 years.
HD 131473 is a binary star system in the northern constellation of Boötes. The primary is an F-type subgiant with a stellar classification of F4IV, while its companion is a G-type subgiant with a stellar classification of G1IV.
ADS 1359 is a quadruple star system in the constellation Cassiopeia. It is composed of two sun like stars in an eclipsing binary with a 2.5-day period, which is in turn orbited by an A-type main-sequence star with a 185-year orbital period. There is also HD 236848 which is a distant proper motion companion.
 | This article about a specific observatory, telescope or astronomical instrument is a stub. You can help Wikipedia by expanding it. |
 | This Belgium-related article is a stub. You can help Wikipedia by expanding it. |
