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Star Hopping
Star hopping is a technique that amateur astronomers often use to locate astronomical objects in the night sky. It can be used instead of or in addition to setting circles or go-to/push-to systems. The problem Many celestial objects of interest are too faint to be visible to the unaided eye. Telescopes or binoculars collect much more light, making faint objects visible, but have a smaller field of view, thus complicating orientation on the sky. The field of view of binoculars is rarely more than eight degrees, while that of typical amateur telescopes may be substantially less than one degree, depending on the magnification used. Many objects are best observed using higher magnifications, which inevitably go along with narrow fields of view. The technique Star hopping uses bright stars as a guide to finding fainter objects. A knowledge of the relative positions of bright stars and target objects is essential. After planning the star hop with the aid of a star chart, the obser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Astronomy
Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the Naked eye, unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers make contributions in doing citizen science, such as by monitoring variable stars, double stars, sunspots, or occultations of stars by the Moon or asteroids, or by discovering transient astronomical events, such as comets, galactic novae or supernovae in other galaxy, galaxies. Amateur astronomers do not use the field of astronomy as their primary source of income or support, and usually have no professional degree in astrophysics or advanced academic training in the subject. Most amateurs are hobbyists, while others have a high degree of experience in astronomy and may often assist and work alongside professional astronomers. Many astronomers have studied the sky throughout history in an amateur framework; however, since the be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterism (astronomy)
An asterism is an observational astronomy, observed pattern or group of stars in the sky. Asterisms can be any identified star pattern, and therefore are a more general concept than the IAU designated constellations, 88 formally defined constellations. Constellations are based upon asterisms, but unlike asterisms, constellations are defined regions with official boundaries which together encompass the entire sky. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. The patterns of stars seen in asterisms are not necessarily a product of any physical association between the stars, but are rather the result of the particular perspectives of their observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globular Cluster
A globular cluster is a spheroidal conglomeration of stars that is bound together by gravity, with a higher concentration of stars towards its center. It can contain anywhere from tens of thousands to many millions of member stars, all orbiting in a stable, compact formation. Globular clusters are similar in form to dwarf spheroidal galaxy, dwarf spheroidal galaxies, and though globular clusters were long held to be the more luminous of the two, discoveries of outliers had made the distinction between the two less clear by the early 21st century. Their name is derived from Latin (small sphere). Globular clusters are occasionally known simply as "globulars". Although one globular cluster, Omega Centauri, was observed in antiquity and long thought to be a star, recognition of the clusters' true nature came with the advent of telescopes in the 17th century. In early telescopic observations, globular clusters appeared as fuzzy blobs, leading French astronomer Charles Messier to incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messier 13
Messier 13, or M13 (also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules, the Hercules Globular Cluster, or the Great Hercules Cluster), is a globular cluster of several hundred thousand stars in the constellation of Hercules (constellation), Hercules. Discovery and visibility Messier 13 was discovered by Edmond Halley in 1714, and cataloged by Charles Messier on June 1, 1764, into his list of objects not to mistake for comets; Messier's list, including Messier 13, eventually became known as the Messier object, Messier catalog. It is located at right ascension 16h 41.7m, declination +36° 28'. Messier 13 is often described by astronomers as the most magnificent globular cluster visible to northern observers. About one third of the way from Vega to Arcturus, four bright stars in Hercules (constellation), Hercules form the Keystone Asterism (astronomy), asterism, the broad torso of the hero. M13 can be seen in this asterism of the way north (Points ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hercules Constellation Map
Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the Greek hero's iconography and myths for their literature and art under the name ''Hercules''. In later Western art and literature and in popular culture, ''Hercules'' is more commonly used than ''Heracles'' as the name of the hero. Hercules is a multifaceted figure with contradictory characteristics, which enabled later artists and writers to pick and choose how to represent him. This article provides an introduction to representations of Hercules in the later tradition. Mythology Birth and early life In Roman mythology, although Hercules was seen as the champion of the weak and a great protector, his personal problems started at birth. Juno sent two witches to prevent the birth, but they were tricked by one of Alcmene's servants and sent t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Astronomical Association
The British Astronomical Association (BAA) was formed in 1890 as a national body to support the UK's amateur astronomers. Throughout its history, the BAA has encouraged observers to make scientifically valuable observations, often in collaboration with professional colleagues. Among the BAA's first presidents was Walter Maunder, discoverer of the seventeenth century dearth in sunspots now known as the Maunder Minimum which he achieved by analysing historical observations. Later, this spirit of observing the night sky scientifically was championed by George Alcock, who discovered five comets and five novae using nothing more than a pair of binoculars. The BAA continues to contribute to the science of astronomy, even despite modern competition from space-based telescopes and highly automated professional observatories. Modern digital sensors, coupled with techniques such as lucky imaging, mean that even modest amateur equipment can rival what professional observatories could h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Declination
In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or south (negative) of the celestial equator, along the hour circle passing through the point in question. The root of the word ''declination'' (Latin, ''declinatio'') means "a bending away" or "a bending down". It comes from the same root as the words ''incline'' ("bend forward") and ''recline'' ("bend backward"). In some 18th and 19th century astronomical texts, declination is given as ''North Pole Distance'' (N.P.D.), which is equivalent to 90 – (declination). For instance an object marked as declination −5 would have an N.P.D. of 95, and a declination of −90 (the south celestial pole) would have an N.P.D. of 180. Explanation Declination in astronomy is comparable to geographic latitude, projected onto the celestial sphere, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ascension
Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in question above the Earth. When paired with declination, these celestial coordinate system, astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' (), "''Ascensio recta'' Solis, stellæ, aut alterius cujusdam signi, est gradus æquatorus cum quo simul exoritur in sphæra recta"; roughly translated, "''Right ascension'' of the Sun, stars, or any other sign, is the degree of the equator that rises together in a right sphere" refers to the ''ascension'', or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator perpendicular, intersects the horizon at a right angle. It contrasts wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Coordinate System
The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of astronomical object, celestial objects. It may be implemented in spherical coordinate system, spherical or Cartesian coordinate system, rectangular coordinates, both defined by an origin (mathematics), origin at the centre of Earth, a fundamental plane (spherical coordinates), fundamental plane consisting of the projective geometry, projection of Earth's equator onto the celestial sphere (forming the celestial equator), a primary direction towards the March equinox, March equinox (celestial coordinates), equinox, and a right-hand rule, right-handed convention. The origin at the centre of Earth means the coordinates are ''geocentric model, geocentric'', that is, as seen from the centre of Earth as if it were transparency and translucency, transparent. The fundamental plane and the primary direction mean that the coordinate system, while aligned with Earth's equator and geograp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Mount
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis, called ''polar axis'', parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescope mount, telescopes and cameras. The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed. Such an arrangement is called a ''sidereal drive'' or ''clock drive''. Equatorial mounts achieve this by aligning their rotational axis with the Earth, a process known as ''polar alignment''. Astronomical telescope mounts In astronomical telescope mounts, the equatorial axis (the ''right ascension'') is paired with a second perpendicular coordinate axis, axis of motion (known as the ''declination''). The equatorial axis of the mount is often equipped with a motorized "''clock drive''", that rotates that axis one revolution e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC Sky At Night
''BBC Sky at Night'' is a British monthly magazine about astronomy aimed at amateur astronomers and published by Immediate Media Company. Its title is taken from the television program produced by the BBC, ''The Sky at Night''. The magazine, in comparison with the TV series, includes more technical and scientific information. Until 2015, it also included a bonus CD-ROM with software programs, the latest astronomical photographs, written materials and 'classic' episodes of ''The Sky at Night'' from the BBC archives (from 2015, the monthly content was moved online). History ''BBC Sky at Night'' was launched in 2005. The first issue, which featured Patrick Moore on the cover and included a copy of Moore's Moon map as a free gift, sold out and back issues are no longer available. Copies of Issue 1 have since sold for over £100 on eBay. In April 2007, the magazine celebrated the 50th anniversary of ''The Sky at Night ''The Sky at Night'' is a documentary television programme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Distance
Angular distance or angular separation is the measure of the angle between the orientation (geometry), orientation of two straight lines, ray (geometry), rays, or vector (geometry), vectors in three-dimensional space, or the central angle subtended by the radius, radii through two points on a sphere. When the rays are Line of sight, lines of sight from an observer to two points in space, it is known as the apparent distance or apparent separation. Angular distance appears in mathematics (in particular geometry and trigonometry) and all natural sciences (e.g., kinematics, astronomy, and geophysics). In the classical mechanics of rotating objects, it appears alongside angular velocity, angular acceleration, angular momentum, moment of inertia and torque. Use The term ''angular distance'' (or ''separation'') is technically synonymous with ''angle'' itself, but is meant to suggest the linear distance between objects (for instance, a pair of stars observed from Earth). Measurement Sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
