Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from Latin: Boōtēs, which comes from Greek: Βοώτης, translit. Boṓtēs 'herdsman' or 'plowman'.
Canes Venatici is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and the constellation is often depicted in illustrations as representing the dogs of Boötes the Herdsman, a neighboring constellation.
The observable universe is a ball-shaped region of the universe consisting of all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time; the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. Initially, it was estimated that there may be 2 trillion galaxies in the observable universe. That number was reduced in 2021 to only several hundred billion based on data from New Horizons. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.
The Sachs–Wolfe effect, named after Rainer K. Sachs and Arthur M. Wolfe, is a property of the cosmic microwave background radiation (CMB), in which photons from the CMB are gravitationally redshifted, causing the CMB spectrum to appear uneven. This effect is the predominant source of fluctuations in the CMB for angular scales larger than about ten degrees.
Constellation Records is a Canadian independent record label based in Montreal, Quebec. It has released albums by many post-rock bands, including Godspeed You! Black Emperor, Thee Silver Mt. Zion Memorial Orchestra & Tra-La-La Band and Do Make Say Think.
A boot is a type of footwear.
Eridanus is a constellation in the southern celestial hemisphere. It is represented as a river. One of the 48 constellations listed by the 2nd century astronomer Ptolemy, it remains one of the 88 modern constellations. It is the sixth largest of the modern constellations, and the one that extends farthest in the sky from north to south. The same name was later taken as a Latin name for the real Po River and also for the name of a minor river in Athens.
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the 88 formally defined constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux.
A constellation is formally any of certain areas of the celestial sphere, or popularly and traditionally a perceived pattern of stars.
The Boötes Void is an approximately spherical region of space found in the vicinity of the constellation Boötes, containing only 60 galaxies instead of the 2000 that should be expected from an area this large, hence its name. With a radius of 62 megaparsecs, it is one of the largest voids in the visible universe, and is referred to as a supervoid.
The Northern Local Supervoid is a region of space devoid of rich clusters of galaxies, known as a void. It is the closest supervoid and is located between the Virgo (Local), Coma and Hercules superclusters. On the sky, it is located between Boötes, Virgo, and Serpens Caput constellations. It contains a few small galaxies and galaxy clusters, but is mostly empty. The faint galaxies within this void divide the region into smaller voids, which are 3–10 times smaller than the supervoid. The center is located 61 Mpc (199 Mly) away at approximately and it is 104 Mpc (339 Mly) in diameter across its narrowest width.
The Great Diamond, also called the Diamond of Virgo, is an asterism that can be seen during spring evenings in the Northern Hemisphere. It is composed of the following stars:
The CMB Cold Spot or WMAP Cold Spot is a region of the sky seen in microwaves that has been found to be unusually large and cold relative to the expected properties of the cosmic microwave background radiation (CMBR). The "Cold Spot" is approximately 70 μK (0.00007 K) colder than the average CMB temperature, whereas the root mean square of typical temperature variations is only 18 μK. At some points, the "cold spot" is 140 μK colder than the average CMB temperature.
Barnard 68 is a molecular cloud, dark absorption nebula or Bok globule, towards the southern constellation Ophiuchus and well within the Milky Way galaxy at a distance of about 125 parsecs. It is both close and dense enough that stars behind it cannot be seen from Earth. American astronomer Edward Emerson Barnard added this nebula to his catalog of dark nebulae in 1919. His catalog was published in 1927, at which stage it included some 350 objects. Because of its opacity, its interior is extremely cold, its temperature being about 16 K (−257 °C/-431 °F). Its mass is about twice that of the Sun and it measures about half a light-year across.
Colin Stetson is a Canadian-American saxophonist, multireedist, and composer based in Montreal. He is best known as a regular collaborator of the indie rock acts Arcade Fire, Bon Iver, Bell Orchestre, and Ex Eye. In addition to saxophone, he plays clarinet, bass clarinet, French horn, flute, and cornet.
A void galaxy is a galaxy located in a cosmological void. Few galaxies exist in voids; most are located in sheets, walls and filaments that surround voids and supervoids. Many void galaxies are connected through void filaments or tendrils, less massive versions of the regular galaxy filaments that surround voids. These filaments are often straighter than their non-void counterparts due to the lack of influence by surrounding filaments. These filaments can even be rich enough to form poor galaxy clusters. The void galaxies themselves are thought to represent pristine examples of galactic evolution, having few neighbours, and likely to have formed from pure intergalactic gas.
The Giant Void is an extremely large region of space with an underdensity of galaxies and located in the constellation Canes Venatici. It is the second-largest-confirmed void to date, with an estimated diameter of 300 to 400 Mpc and its centre is approximately 1.5 billion light-years away. It was discovered in 1988, and was the largest void in the Northern Galactic Hemisphere, and possibly the second-largest ever detected. Even the hypothesized "Eridanus Supervoid" corresponding to the location of the WMAP cold spot is dwarfed by this void, although the Giant Void does not correspond to any significant cooling to the cosmic microwave background.
The KBC Void is an immense, comparatively empty region of space, named after astronomers Ryan Keenan, Amy Barger, and Lennox Cowie, who studied it in 2013. The existence of a local underdensity has been the subject of many pieces of literature and research articles.
