|
ε Crucis
Epsilon Crucis, Latinised from ε Crucis (abbreviated Epsilon Cru, ε Cru) and also known as Ginan , is a single, orange-hued star in the southern constellation of Crux. Measurements made by the Gaia spacecraft showed an annual parallax shift of 14.2 mas, which provides a distance estimate of about 230 light-years. The star can be seen with the naked eye, having an apparent visual magnitude of 3.58. It is moving closer to the Sun with a radial velocity of −4.60 km/s. This is a giant star of type K with a stellar classification of K3III, indicating that it has exhausted the hydrogen at its core and evolved away from the main sequence. It is about two billion years old with 1.4–1.5 times the mass of the Sun and has expanded to 31 times the Sun's radius. The star is shining with around 282 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,210 K. Nomenclature ε Crucis ( Latinised to ''Epsilon Crucis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Of The Sun
The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. More precisely, the mass of the Sun is The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry of Earth. The first known estimate of the solar mass was by Isaac N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flag Of Australia
The national flag of Australia is based on the British Blue Ensign—a blue field with the Union Jack in the upper hoist quarter—augmented with a large white seven-pointed star (the Commonwealth Star) and a representation of the Crux, Southern Cross constellation, made up of five white stars (Epsilon Crucis, one small five-pointed star and four, larger, seven-pointed stars). Australia also has a number of other #Other Australian flags, official flags representing its States and territories of Australia, states and territories, Indigenous Australians, Indigenous peoples and government bodies. The original version of the flag first flew as the Commonwealth blue ensign on 3 September 1901, after being selected alongside a merchant naval Australian red ensign, red ensign in 1901 Federal Flag Design Competition, a competition held following Federation of Australia, Federation. A slightly simplified version as approved by King Edward VII was officially adopted in 1903. It was later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portuguese Language
Portuguese ( or ) is a Western Romance language of the Indo-European language family originating from the Iberian Peninsula of Europe. It is the official language of Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique, Portugal and São Tomé and PrÃncipe, and has co-official language status in East Timor, Equatorial Guinea and Macau. Portuguese-speaking people or nations are known as Lusophone (). As the result of expansion during colonial times, a cultural presence of Portuguese speakers is also found around the world. Portuguese is part of the Iberian Romance languages, Ibero-Romance group that evolved from several dialects of Vulgar Latin in the medieval Kingdom of Galicia and the County of Portugal, and has kept some Gallaecian language, Celtic phonology. With approximately 250 million native speakers and 17 million second language speakers, Portuguese has approximately 267 million total speakers. It is usually listed as the List of languages by number of native speaker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Crucis
Acrux is the brightest star in the southern constellation of Crux. It has the Bayer designation α Crucis, which is Latinised to Alpha Crucis and abbreviated Alpha Cru or α Cru. With a combined visual magnitude of +0.76, it is the 13th-brightest star in the night sky. It is the most southerly star of the asterism known as the Southern Cross and is the southernmost first-magnitude star, 2.3 degrees more southerly than Alpha Centauri. This system is located at a distance of 321 light-years from the Sun. To the naked eye Acrux appears as a single star, but it is actually a multiple star system containing six components. Through optical telescopes, Acrux appears as a triple star, whose two brightest components are visually separated by about 4 arcseconds and are known as Acrux A and Acrux B, α1 Crucis and α2 Crucis, or α Crucis A and α Crucis B. Both components are B-type stars, and are many times more massive and luminous than the Sun. This system was the second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IAU Working Group On Star Names
The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education, Outreach and Heritage. The IAU states that it is keen to make a distinction between the terms ''name'' and ''designation''. To the IAU, ''name'' refers to the (usually colloquial) term used for a star in everyday conversation, while ''designation'' is solely alphanumerical, and used almost exclusively in official catalogues and for professional astronomy. (The WGSN notes that transliterated Bayer designations (e.g., Tau Ceti) are considered a special historical case and are treated as designations.) Terms of reference The terms of reference for the WGSN for the period 2016–2018 were approved by the IAU Executive Committee at its meeting on 6 May 2016. In summary, these are to: * establish IAU guidelines for the proposal and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilly Bag
A dillybag or dilly bag is a traditional Australian Aboriginal bag generally woven from plant fibres. Dillybags are mainly designed and used by women to gather and transport food, and are most commonly found in the northern parts of Australia. ''Dilly'' comes from the Jagera word ''dili'', which refers to both the bag and the plants from which it is made. Amongst some Aboriginal peoples dillybags are alternatively known as yakou, yibali, or but but bags. Some forms of dillybags are worn like a satchel with a cord around the neck; most come in an oval shape with a cord attached for carrying. Dillybags are normally woven out of vines or tough dried grasses. In Arnhem Land, Queensland, the Northern Territory and northern Western Australia, plant species of the ''Pandanus'' genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller islands. It has a total area of , making it the list of countries and dependencies by area, sixth-largest country in the world and the largest in Oceania. Australia is the world's flattest and driest inhabited continent. It is a megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and Climate of Australia, climates including deserts of Australia, deserts in the Outback, interior and forests of Australia, tropical rainforests along the Eastern states of Australia, coast. The ancestors of Aboriginal Australians began arriving from south-east Asia 50,000 to 65,000 years ago, during the Last Glacial Period, last glacial period. By the time of British settlement, Aboriginal Australians spoke 250 distinct l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Territory
The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regions of Australia. The Northern Territory shares its borders with Western Australia to the west (129th meridian east), South Australia to the south (26th parallel south), and Queensland to the east (138th meridian east). To the north, the Northern Territory looks out to the Timor Sea, the Arafura Sea, and the Gulf of Carpentaria, including Western New Guinea and various other islands of the Indonesian archipelago. The NT covers , making it the third-largest Australian federal division, and List of country subdivisions by area, the 11th-largest country subdivision in the world. It is sparsely populated, with a population of only 249,000 – fewer than half the population of Tasmania. The largest population centre is the capital city of Darw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wardaman People
The Wardaman people are a small group of Aboriginal Australians living about South-West of Katherine, on Menngen Aboriginal Land Trust in the Northern Territory of Australia. Language Wardaman is a non- Pama-Nyungan language. Though close to being a moribund language, it was, as late as the early 1990s, one of the most widely spoken Aboriginal languages in Katherine, with an estimated 30 speakers and perhaps 200 or more people who could understand it if spoken. Country The Wardaman controlled, according to Norman Tindale, some of territory from the headwaters of the southern branches of the upper Flora River, and westwards as far as the Victoria River Depot. Their southern limits lay around Jasper Gorge. The Wardaman presence, attested in post-contact times, at Delamere is historically recent. History of contact European contact with Wardaman and related peoples like the Dagoman and Yangman was characterized from the outset by considerable violence. Eventually, as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer Designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1564 stars. The brighter stars were assigned their first systematic names by the German astronomer Johann Bayer in 1603, in his star atlas ''Uranometria''. Bayer catalogued only a few stars too far south to be seen from Germany, but later astronomers (including Nicolas-Louis de Lacaille and Benjamin Apthorp Gould) supplemented Bayer's catalog with entries for southern constellations. Scheme Bayer assigned a lowercase Greek alphabet, Greek letter (alpha (α), beta (β), gamma (γ), etc.) or a Latin letter (A, b, c, etc.) to each star he catalogued, combined with the Latin name of the star's parent constellation in genitive case, genitive (possessive) form. The constellation name is frequently abbreviated to a standard three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known. When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less than that of a black body), the actual temperature of the body will be higher than the effective temperature. The net emissivity may be low due to surface or atmospheric properties, such as the greenhouse effect. Star The effective temperature of a star is the temperature of a black body with the same luminosity per ''surface area'' () as the star and is defined according to the Stefan–Boltzmann law . Notice that the total ( bolometric) luminosity of a star is then , where is the stellar radius. The definition of the stellar radius is obviously not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
