Search results
Results from the WOW.Com Content Network
Betelgeuse's color may have changed from yellow (or possibly orange; i.e. a yellow supergiant) to red in the last few thousand years, based on a 2022 review of historical records. This color change combined with the CMD suggest a mass of 14 M ☉, an age of 14 million year and a distance from 125 to 150 parsecs (~400 to 500 light years). [12]
A goose (pl.: geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera Anser (grey geese and white geese) and Branta (black geese). Some members of the Tadorninae subfamily (e.g., Egyptian goose, Orinoco goose) are commonly called geese, but are not considered "true geese" taxonomically. [1]
The CIE photopic luminous efficiency function y (λ) or V(λ) is a standard function established by the Commission Internationale de l'Éclairage (CIE) and standardized in collaboration with the ISO, [1] and may be used to convert radiant energy into luminous (i.e., visible) energy. It also forms the central color matching function in the CIE ...
Luminous energy per unit time Luminous intensity: I v: candela (= lumen per steradian) cd (= lm/sr) J: Luminous flux per unit solid angle: Luminance: L v: candela per square metre: cd/m 2 (= lm/(sr⋅m 2)) L −2 ⋅J: Luminous flux per unit solid angle per unit projected source area. The candela per square metre is sometimes called the nit ...
Eurasian cranes in a V formation (video) Birds flying in V formation. A V formation is a symmetric V- or chevron-shaped flight formation.In nature, it occurs among geese, swans, ducks, and other migratory birds, improving their energy efficiency, while in human aviation, it is used mostly in military aviation, air shows, and occasionally commercial aviation.
Articles relating to Geese, birds of any of several waterfowl species in the family Anatidae. This group comprises the genera Anser (grey geese and white geese) and Branta (black geese). Some members of the Tadorninae subfamily (e.g., Egyptian goose, Orinoco goose) are commonly called geese, but are not considered "true geese" taxonomically.
Goose breeds are usually grouped into three weight classes: Heavy, Medium and Light. Most domestic geese are descended from the greylag goose (Anser anser). The Chinese and African Geese are the domestic breeds of the swan goose (A. cygnoides); they can be recognized by their prominent bill knob. [1]
Luminous energy per unit time Luminous intensity: I v: candela (= lumen per steradian) cd (= lm/sr) J: Luminous flux per unit solid angle: Luminance: L v: candela per square metre: cd/m 2 (= lm/(sr⋅m 2)) L −2 ⋅J: Luminous flux per unit solid angle per unit projected source area. The candela per square metre is sometimes called the nit ...