 | This article does not cite any sources .(December 2009) (Learn how and when to remove this template message) |
Compression Networks is a digital content delivery system developed by TV/COM International that evolved into the current DVB-S standard for satellite broadcasting. The system provided MPEG2 video, audio, signalling, enhanced program guide, and conditional access for pay-television services like AlphaStar.
 | This article about television technology is a stub. You can help Wikipedia by expanding it. |
Apparent magnitude is a measure of the brightness of a star or other astronomical object observed from the Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer.
Alpha Centauri is the closest star system and closest planetary system to Earth's Solar System at 4.37 light-years from the Sun. It is a triple star system, consisting of three stars: α Centauri A, α Centauri B, and α Centauri C.
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917, but was not recognized as such. The first confirmation of detection occurred in 1992. This was followed by the confirmation of a different planet, originally detected in 1988. As of 1 February 2020, there are 4,173 confirmed exoplanets in 3,096 systems, with 678 systems having more than one planet.
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
A star is an astronomical object consisting of a luminous spheroid of plasma held together by its own gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye from Earth during the night, appearing as a multitude of fixed luminous points in the sky due to their immense distance from Earth. Historically, the most prominent stars were grouped into constellations and asterisms, the brightest of which gained proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable Universe contains an estimated 1×1024 stars, but most are invisible to the naked eye from Earth, including all stars outside our galaxy, the Milky Way.
The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, the dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.
Sirius is the brightest star in the night sky. Its name is derived from the Greek word Σείριος Seirios "glowing" or "scorching". With a visual apparent magnitude of −1.46, Sirius is almost twice as bright as Canopus, the next brightest star. Sirius is a binary star consisting of a main-sequence star of spectral type A0 or A1, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The distance between the two varies between 8.2 and 31.5 astronomical units as they orbit every 50 years.
The following are lists of stars. These are astronomical objects that spend some portion of their existence generating energy through thermonuclear fusion.
The zodiac is an area of the sky that extends approximately 8° north or south of the ecliptic, the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets are also within the belt of the zodiac.
A binary star is a star system consisting of two stars orbiting around their common barycenter. Systems of two or more stars are called multiple star systems. These systems, especially when more distant, often appear to the unaided eye as a single point of light, and are then revealed as multiple by other means.
An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe. In astronomy, the terms object and body are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial object is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures.
The Most Excellent Order of the British Empire is a British order of chivalry, rewarding contributions to the arts and sciences, work with charitable and welfare organisations, and public service outside the civil service. It was established on 4 June 1917 by King George V and comprises five classes across both civil and military divisions, the most senior two of which make the recipient either a knight if male or dame if female. There is also the related British Empire Medal, whose recipients are affiliated with, but not members of the order.
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a star cluster or galaxy, although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies.
A planetary system is a set of gravitationally bound non-stellar objects in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with the planets revolving around it, including Earth, is known as the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
A multiplayer video game is a video game in which more than one person can play in the same game environment at the same time, either locally or online over the internet. Multiplayer games usually require players to share the resources of a single game system or use networking technology to play together over a greater distance; players may compete against one or more human contestants, work cooperatively with a human partner to achieve a common goal, supervise other players' activity, co-op. Multiplayer games allow players interaction with other individuals in partnership, competition or rivalry, providing them with social communication absent from single-player games.
In astronomy, magnitude is a unitless measure of the brightness of an object in a defined passband, often in the visible or infrared spectrum, but sometimes across all wavelengths. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus.
The planetary systems of stars other than the Sun and the Solar System are a staple element in many works of the science fiction genre.
Hotel ratings are often used to classify hotels according to their quality. From the initial purpose of informing travellers on basic facilities that can be expected, the objectives of hotel rating have expanded into a focus on the hotel experience as a whole. Today the terms 'grading', 'rating', and 'classification' are used to generally refer to the same concept, that is to categorize hotels.