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Pelorus (instrument)
In marine navigation, a pelorus is a reference tool for maintaining bearing of a vessel at sea. It is a "simplified compass" without a directive element, suitably mounted and provided with vanes to permit observation of relative bearings. The instrument was named for one Pelorus, said to have been the pilot for Hannibal, circa 203 BC. Ancient use Harold Gatty described the use of a pelorus by Polynesians before the use of a compass. In equatorial waters the nightly course of stars overhead is nearly uniform during the year. This regularity simplified navigation for the Polynesians using a pelorus, or dummy compass: Reading from North to South, in their rising and setting positions, these stars are:List comes from Tolmacheva (1980:p. 183), based "with some reservations" on Tibbets (1971: p. 296, n. 133). The sidereal rose given in Lagan (2005p.66 has some differences, e.g. placing Orion's belt in East and Altair in EbN. : The true position of these stars is only approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMS Belfast - Wheelhouse - Pelorus
HMS or hms may refer to: Education * Habib Medical School, of the Islamic University in Uganda * Hartley–Melvin–Sanborn Community School District of Iowa, United States * Harvard Medical School of Harvard University * Heidelberg Middle School, a former American school in Heidelberg, Germany * Hongwanji Mission School, in Hawaii, United States * Horley Methodist School, Teluk Intan, in Malaysia Medicine and science * Hartford Medical Society, an American professional association based in Hartford, Connecticut * Health management system * Hexose monophosphate shunt, an alternative name for the pentose phosphate pathway * Highly migratory species, a classification of fish * Hypermobility spectrum disorder, formerly hypermobility syndrome or HMS * HMS, a brand name of medrysone Technology * Huawei Mobile Services, proprietary apps and services from Huawei bundled with Android devices * HMS Networks, a company in the field of industrial communications * Heavy meltin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altair
Altair is the brightest star in the constellation of Aquila (constellation), Aquila and the list of brightest stars, twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinisation of names, Latinised from α Aquilae and abbreviated Alpha Aql or α Aql. Altair is an A-type main-sequence star, A-type main-sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle Asterism (astronomy), asterism; the other two vertices are marked by Deneb and Vega. It is located at a distance of from the Sun. Altair is currently in the G-cloud—a nearby interstellar cloud formed from an accumulation of gas and dust. Altair rotates rapidly, with a velocity at the equator of approximately 286 km/s.From values of ''v'' sin ''i'' and ''i'' in the second column of Table 1, Monnier et al. 2007. This is a significant fraction of the star's estimated breakup speed of 400 km/s. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Rose
A compass rose or compass star, sometimes called a wind rose or rose of the winds, is a polar coordinates, polar diagram displaying the orientation of the cardinal directions (north, east, south, and west) and their points of the compass, intermediate points. It is used on compass, compasses (including magnetic compass, magnetic ones), maps (such as compass rose networks), or monuments. It is particularly common in navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, satellite navigation devices ("GPS (device), GPS"). Types Linguistic anthropological studies have shown that most human communities have four points of cardinal direction. The names given to these directions are usually derived from either locally-specific geographic features (e.g. "towards the hills", "towards the sea") or from celestial bodies (especially the sun) or from atmospheric features (winds, temperature). Most mobile populations tend to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubber Line
A lubber line, also known as a lubber's line, is a fixed line on the binnacle of a compass, or a plan position indicator radar display, pointing towards the front of the ship or aircraft, and corresponding to the craft's centerline (being the customary direction of movement). The line represents 0 degrees and is therefore the zero point from which relative bearings are measured, e.g., "twenty degrees to port". Compasses on sailboats may have additional lubber lines at forty-five degrees from the centerline. This represents about as close to the wind as the average boat will sail. These lubber lines may be used when sailing close hauled A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind ... to see if one is on the closest course to the destination, without having to add or subtract the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Repeater
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings which are commonly stated in degrees. If local variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the Chinese Han dynasty (since c. 206 BC), Li Shu-hua, p. 176 and later adopted for navigation by the Song dynasty Chinese during the 11th centur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with North magnetic pole, magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers. Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearing (angle), bearings which are commonly stated in degrees. If local magnetic declination, variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north. Among the Four Great Inventions, the magnetic compass was first invented as a device for divination as early as the history of science and technology in China, Chinese Han dynasty (since c. 206 BC),#Li, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass Rose
A compass rose or compass star, sometimes called a wind rose or rose of the winds, is a polar coordinates, polar diagram displaying the orientation of the cardinal directions (north, east, south, and west) and their points of the compass, intermediate points. It is used on compass, compasses (including magnetic compass, magnetic ones), maps (such as compass rose networks), or monuments. It is particularly common in navigation systems, including nautical charts, non-directional beacons (NDB), VHF omnidirectional range (VOR) systems, satellite navigation devices ("GPS (device), GPS"). Types Linguistic anthropological studies have shown that most human communities have four points of cardinal direction. The names given to these directions are usually derived from either locally-specific geographic features (e.g. "towards the hills", "towards the sea") or from celestial bodies (especially the sun) or from atmospheric features (winds, temperature). Most mobile populations tend to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Cross
CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system to install and upgrade applications. Although ''crux'' is the Latin word for "cross," the choice of the name "CRUX" itself has no meaning. Per Lidén chose it because it "sounded cool," and ends in "X" which puts it in line with various other Unix flavors such as IRIX, Ultrix, Mac OS X and IBM AIX. Installation CRUX does not include a GUI installation program. Instead, the user boots the kernel stored on either a CD or diskette; partitions the hard disk drive(s) to which the operating system will be installed (using a program such as fdisk or cfdisk); creates the appropriate file systems on the various partitions; mounts the CD or NFS share along with the partitions made previously for use by the package installation script; comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achernar
Achernar is the brightest star in the constellation of Eridanus and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Achernar applies to the primary component of a binary system. The two components are designated Alpha Eridani A (the primary) and B (the secondary), with the latter known informally as Achernar B. As determined by the ''Hipparcos'' astrometry satellite, this system is located at a distance of approximately from the Sun. Of the ten brightest stars in the night-time sky by apparent magnitude, Alpha Eridani is the hottest and bluest in color because it is spectral type B. Achernar has an unusually rapid rotational velocity, causing it to become oblate in shape. The secondary is smaller, is spectral type A, and orbits Achernar at a distance of . Nomenclature ''α Eridani'' ( Latinised to ''Alpha Eridani'') is the system's Bayer designati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canopus
Canopus is the brightest star in the southern constellation of Carina (constellation), Carina and the list of brightest stars, second-brightest star in the night sky. It is also Bayer designation, designated α Carinae, which is Romanization, romanized (Transliteration, transliterated) to Alpha Carinae. With a visual apparent magnitude of −0.74, it is outshone only by Sirius. Located around from the Sun, Canopus is a bright giant of spectral type A9, so it is essentially white when seen with the naked eye. It has a luminosity over 10,000 times the luminosity of the Sun, is nine to ten times as mass of the Sun, massive, and has expanded to 71 times the Sun's radius. Its enlarged photosphere has an effective temperature of around . Canopus is undergoing stellar core, core helium fusion, helium burning and is currently in the so-called blue loop phase of its stellar evolution, evolution, having already passed through the red-giant branch after exhausting the h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Centauri
Alpha Centauri (, α Cen, or Alpha Cen) is a star system in the southern constellation of Centaurus (constellation), Centaurus. It consists of three stars: Rigil Kentaurus (), Toliman (), and Proxima Centauri (). Proxima Centauri is the List of nearest stars, closest star to the Sun at 4.2465 light-years (ly) which is 1.3020 parsecs (pc). Rigil Kentaurus and Toliman are Sun-like stars (G-type main-sequence star, class G and K-type main-sequence star, K, respectively) that together form the binary star system . To the naked eye, these two main components appear to be a single star with an apparent magnitude of −0.27. It is the brightest star in the constellation and the List of brightest stars, third-brightest in the night sky, outshone by only Sirius and Canopus. Rigil Kentaurus has 1.1 times the Solar mass, mass () and 1.5 times the Solar luminosity, luminosity of the Sun (), while Toliman is smaller and cooler, at and less than . The pair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antares
Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinisation of names, Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by Sigma Scorpii, σ Scorpii and Tau Scorpii, τ Scorpii near the center of the constellation. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from an apparent visual magnitude of +0.6 down to +1.6. It is on average list of brightest stars, the fifteenth-brightest star in the night sky. Antares is the brightest and most evolved stellar member of the Scorpius–Centaurus association, the nearest Stellar association#OB associations, OB association to the Sun. It is located about from Earth at the rim of the Upper Scorpius subgroup, and is illuminating the Rho Ophiuchi cloud complex in its foreground. Classified as stellar classification#Spectral types, spectral type Stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
