Alcor ( / ˈ æ l k ɔːr / ) is a binary star system in the constellation of Ursa Major . It is the fainter companion of Mizar , the two stars forming a naked eye double in the handle of the Big Dipper (or Plough) asterism in Ursa Major. The two lie about 83 light-years away from the Sun , as measured by the Hipparcos astrometry satellite.
13-520: Alcor may refer to: Alcor (star) , also known as 80 Ursae Majoris, a star in Ursa Major very close to Mizar Alcor Life Extension Foundation Alcor sailplane , a high altitude pressurized sailplane developed by aeronautical engineer Robert Lamson ALCOR , a programming language French name of the anime and manga hero Kouji Kabuto See also [ edit ] USS Alcor Topics referred to by
26-516: A table of the first two batches of names approved by the WGSN; which included Alcor for 80 UMa. With normal eyesight Alcor appears at about 12 minutes of arc from the second-magnitude star Mizar. Alcor is of magnitude 3.99 and spectral class A5V. Mizar's and Alcor's proper motions show they move together, along with most of the other stars of the Big Dipper except Dubhe and Alkaid , as members of
39-643: Is different from Wikidata All article disambiguation pages All disambiguation pages Alcor (star) Alcor has the Flamsteed designation 80 Ursae Majoris . Alcor derives from Arabic الخوار al-khawāri , meaning 'faint one'; notable as a faintly perceptible companion of Mizar . In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included
52-752: The American Museum of Natural History , is the principal investigator for the project. The two main instruments behind Project 1640 is an Integral field spectrograph (IFS) and an Apodized-pupil Lyot coronagraph at the Hale Telescope at Palomar. This instrument is the basis of a high-contrast imaging long-term observational program. The instrument uses the chromatic nature of the speckle noise to distinguish it from any true astrophysical companions, including software which increases sensitivity by 10-20 times. Such sensitivity can detect planets of several Jupiter masses . The spectrograph obtains 23 images across
65-422: The J and H bands (1.06-1.78 μm ), with a spectral resolution of 45. In approximately 2013, a Post-coronagraph Wave Front Calibration System was added. Its goal is to achieve a wave front irregularity of less than 10 nm. On March 10, 2013, Project 1640 made its first remote imaging of another solar system. It imaged four red exoplanets orbiting the star HR8799 , 128 light years away from Earth, determining
78-498: The Ursa Major Moving Group , a mostly dispersed group of stars sharing a common birth. However, it has yet to be demonstrated conclusively that they are gravitationally bound. Recent studies indicate that Alcor and Mizar are somewhat closer together than previously thought: approximately 74,000 ± 39,000 AU , or 0.5–1.5 light-years. The uncertainty is due to our uncertainty about the exact distances from us. If they are exactly
91-518: The Ursa Major Moving Group , a stellar group of stars of similar ages and velocities, and the closest cluster-like object to Earth. In Arabic, Alcor is also known as Al-Sahja (the rhythmical form of the usual al-Suhā) meaning "forgotten", "lost", or "neglected". In traditional Indian astronomy , Alcor was known as Arundhati , wife of one of the Saptarishi . In the Miꞌkmaq myth of the great bear and
104-471: The 5-meter Hale Telescope at Palomar Observatory . Alcor B is one second of arc away from Alcor A. Its spectral type is M3-4 and it is a main-sequence star , a red dwarf. Alcor A and B are situated 1.2 light-years away from, and are co-moving with, the Mizar quadruple system, making the system the second-closest stellar sextuplet—only Castor is closer. The Mizar–Alcor stellar sextuple system belongs to
117-520: The 6.5-meter telescope at MMT Observatory . Another led by Neil Zimmerman, a graduate student at Columbia University and member of Project 1640 , an international collaborative team that includes astrophysicists at the American Museum of Natural History , the University of Cambridge 's Institute of Astronomy, the California Institute of Technology , and NASA 's Jet Propulsion Laboratory , used
130-419: The same distance from us (somewhat unlikely) then the distance between them is only 17,800 AU (0.281 light-years). In 2009, Alcor was discovered to have a companion star Alcor B, a magnitude 8.8 red dwarf . Alcor B was discovered independently by two groups. One group led by Eric Mamajek ( University of Rochester ) and colleagues at Steward Observatory University of Arizona used adaptive optics on
143-407: The same term [REDACTED] This disambiguation page lists articles associated with the title Alcor . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Alcor&oldid=1003672183 " Category : Disambiguation pages Hidden categories: Short description
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#1733085061614156-486: The seven hunters, Mizar is Chickadee and Alcor is his cooking pot. USS Alcor (AD-34) and USS Alcor (AK-259) are both United States Navy ships. Project 1640 Project 1640 is a high contrast imaging project at Palomar Observatory . It seeks to image brown dwarfs and Jupiter-sized planets around nearby stars. Rebecca Oppenheimer , associate curator and chair of the Astrophysics Department at
169-453: The spectra for all four. One significant result was the detection of a chemical abnormality. At normal temperatures, such as those surrounding the four exoplanets, ammonia and methane should both be present in significant amounts. However, the exoplanets have either ammonia or methane in abundance, while the other chemical is missing. Other chemicals such as acetylene (not previously detected on any exoplanet) may also be present. There
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