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List of Largest Stars
Below is a list of the largest stars currently known, ordered by radius. The unit of measurement used is the radius of the Sun (approximately 695,700 km; 432,300 mi). The angular diameters of stars can be measured directly using stellar interferometry. Other methods can use lunar occultations or from eclipsing binaries, which can be used to test indirect methods of finding stellar radii. Only a few useful supergiant stars can be occulted by the Moon, including Antares A (Alpha Scorpii A). Examples of eclipsing binaries are Epsilon Aurigae (Almaaz), VV Cephei, and V766 Centauri (HR 5171). Angular diameter measurements can be inconsistent because the boundary of the very tenuous atmosphere (opacity) differs depending on the wavelength of light in which the star is observed. Uncertainties remain with the membership and order of the list, especially when deriving various parameters used in calculations, such as stellar luminosity and effective temperature. Often stellar radii can only be expressed as an average or be within a large range of values. Values for stellar radii vary significantly in different sources and for different observation methods. All the sizes stated in this list have various inaccuracies and may be disputed. This list is still a work in progress and various parameters are extremely disputed.
  • 1.5K
  • 21 Nov 2022
Topic Review
List of Messier Objects
The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his "Catalogue des Nébuleuses et des Amas d'Étoiles" ("Catalogue of Nebulae and Star Clusters"). A preliminary version first appeared in Memoirs of the French Academy of Sciences in 1771, and the last item was added in 1966 by Kenneth Glyn Jones, based on Messier's observations. The first version of Messier's catalogue contained 45 objects and was published in 1774 in the journal of the French Academy of Sciences in Paris. In addition to his own discoveries, this version included objects previously observed by other astronomers, with only 17 of the 45 objects being Messier’s. By 1780 the catalog had increased to 80 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784. However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually filled out the list up to 110 objects. The catalogue consists of a diverse range of astronomical objects, ranging from star clusters, nebula and galaxies. Messier 1 is the supernova remnant of Crab Nebula and the great spiral Andromeda Galaxy is M 31. Many further inclusions followed in the next century when the first addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier’s side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967. Because Messier was interested in finding only comets, he created a list of non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as the Messier catalogue. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier number.
  • 566
  • 06 Dec 2022
Topic Review
List of Meteor Air Bursts
Many explosions recorded in Earth's atmosphere are likely to be caused by the air bursts that result from meteors exploding as they hit the thicker part of the atmosphere. These types of meteors are also known as fireballs or bolides with the brightest known as superbolides. Before entering Earth's atmosphere, these larger meteors were originally asteroids and comets of a few to several tens of metres in diameter, contrasting with the much smaller and much more common "shooting stars". The most powerful recorded air burst is the 1908 Tunguska event. Extremely bright fireballs traveling across the sky are often witnessed from a distance, such as the 1947 Sikhote-Alin meteor and the 2013 Chelyabinsk meteor, both in Russia. If the bolide is large enough, fragments may survive such as the Chelyabinsk meteorite. Modern developments in infrasound detection by the Comprehensive Nuclear-Test-Ban Treaty Organization and infrared Defense Support Program satellite technology have increased the likelihood of detecting airbursts.
  • 1.7K
  • 11 Nov 2022
Topic Review
List of Objects at Lagrangian Points
This is a list of known objects which occupy, have occupied, or are planned to occupy any of the five Lagrangian points of two-body systems in space.
  • 1.2K
  • 08 Nov 2022
Topic Review
List of Photonics Equations
This article summarizes equations in the theory of photonics, including geometric optics, physical optics, radiometry, diffraction, and interferometry.
  • 218
  • 17 Oct 2022
Topic Review
List of Rooftop Photovoltaic Installations
This lists large-scale rooftop photovoltaic installation projects. Photovoltaic arrays in buildings are often either integrated into them, or mounted on to their roofs. Arrays are most often retrofitted into existing buildings, usually mounted on top of the existing roof structure. In 2010, more than four-fifths of the 9,000 MW of solar PV operating in Germany was installed on rooftops. Most of the large-scale stations are not installed on the roofs, but rather integrated are ground-mounted. Most rooftop applications are done in small and medium-sized installations for consumption within the buildings that host the arrays. There are many significant installation projects which have been completed and many are under construction or proposed. The following lists the rooftop photovoltaic installation projects that are larger than 1 MW in total installation size. It does not include rooftop installations of non-building structures such as detached carports and tunnels.
  • 968
  • 12 Oct 2022
Topic Review
List of Unnumbered Minor Planets: 2001 A–R
This is a partial list of unnumbered minor planets for principal designations assigned between 1 January 2001 and 15 September 2001 (A–R).
  • 240
  • 24 Oct 2022
Topic Review
List of Unnumbered Minor Planets: 2001 S–Y
This is a partial list of unnumbered minor planets for principal designations assigned between 16 September 2001 and 31 December 2001 (S–Z).
  • 226
  • 29 Nov 2022
Topic Review
List of Unnumbered Minor Planets: 2002 A–O
This is a partial list of unnumbered minor planets for principal designations assigned between 1 January 2002 and 31 July 2002 (A–O).
  • 266
  • 29 Nov 2022
Topic Review
List of Unnumbered Minor Planets: 2002 P–Q
This is a partial list of unnumbered minor planets for principal designations assigned between 1 August 2002 and 31 August 2002 (P–Q).
  • 316
  • 10 Nov 2022
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