A0, A-0, A₀, or a₀ may refer to: * 101 A0 and 103 A0, two versions of the German Heinkel Tourist moped *

A0 paper size ISO 216 is an international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, including A4, the most commonly available paper size ...

, an international ISO 216 standard paper size (841 × 1189 mm), which results in an area very close to 1 m² *

A0 highway (Zimbabwe) The government of Zimbabwe is the main provider of air, rail and road services; historically, there has been little participation of private investors in transport infrastructure. Railways The railway operator is National Railways of Zimbabwe. ...

, a highway which orbits Zimbabwe * A0, the lowest A (musical note) note on a standard piano * A0, a

climbing grade In rock climbing, mountaineering, and other climbing disciplines, climbers give a grade to a climbing route or boulder problem, intended to describe concisely the difficulty and danger of climbing it. Different types of climbing (such as spor ...

* A00, Irregular chess openings code in the Encyclopaedia of Chess Openings *

A-0 Geyser A-0 Geyser is a geyser in the Lower Geyser Basin of Yellowstone National Park in the United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located ...

, a geyser in Yellowstone National Park * A-0 System, an early compiler related tool developed for electronic computers * L'Avion, IATA airline designator for the French airline * Characters of type A₀, an older term for algebraic Hecke characters * a₀, the accepted mathematical symbol for the Bohr radius * Haplogroup A00 and A0; see

Y-chromosomal Adam In human genetics, the Y-chromosomal most recent common ancestor (Y-MRCA, informally known as Y-chromosomal Adam) is the Patrilineality, patrilineal most recent common ancestor (MRCA) from whom all Present day, currently living humans are descended ...

and Haplogroup A (Y-DNA) * A0, a subdivision in

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

* A0, sometimes written as 0xA0, is the hexadecimal representation of

non-breaking space In word processing and digital typesetting, a non-breaking space, , also called NBSP, required space, hard space, or fixed space (though it is not of fixed width), is a space character that prevents an automatic line break at its position. In s ...

in various character encoding standards *

A0 road (Sri Lanka) The A 0 is an A-Grade road in Sri Lanka. It connects Kollupitiya and Sri Jayawardanapura, the nation's capital. The highway passes through Rajagiriya Rajagiriya is part of the Sri Lanka's administrative capital of Sri Jayawardenapura. A fair ...

, an A-Grade road in Sri Lanka

Airplanes and rockets

* A-0, a 1943 Pre-production model of the German

Walter HWK 509 The Walter HWK 109-509 was a German liquid-fuel bipropellant rocket engine that powered the Messerschmitt Me 163 Komet and Bachem Ba 349 aircraft. It was produced by Hellmuth Walter Kommanditgesellschaft (HWK) commencing in 1943, with licensed p ...

liquid-fuel bipropellant rocket engine * A-0, a 1938 variant of the German Siebel Si 204 transport and trainer aircraft * He 177 A-0, a pre-production series of the 1942 German Heinkel He 177 heavy bomber * Hs 126A-0, a variant of the 1937 German Henschel Hs 126 reconnaissance aircraft * Ju 87 A-0, a variant of the 1936 German

Junkers Ju 87 The Junkers Ju 87 or Stuka (from ''Sturzkampfflugzeug'', "dive bomber") was a German dive bomber and ground-attack aircraft. Designed by Hermann Pohlmann, it first flew in 1935. The Ju 87 made its combat debut in 1937 with the Luftwaffe's Con ...

dive bomber aircraft * Me 210A-0, a pre-production variant of the 1943 German Messerschmitt Me 210 heavy fighter aircraft

Submarine

* '' Isaac Peral'' (A-0), a Spanish submarine

Airplanes and rockets

Submarine

See also