O3 may refer to:

Science and technology

Ozone Ozone () (or trioxygen) is an Inorganic compound, inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , break ...

(O₃), an allotrope of oxygen * , the ozonide anion *

O(3) In mathematics, the orthogonal group in dimension , denoted , is the group of distance-preserving transformations of a Euclidean space of dimension that preserve a fixed point, where the group operation is given by composing transformations. T ...

, the 3-dimensional orthogonal group in group theory * O3 star, a subclass of the

O-type star An O-type star is a hot, blue star of spectral type O in the Yerkes classification system employed by astronomers. They have surface temperatures in excess of 30,000 kelvins (K). Stars of this type have strong absorption lines of ionised h ...

stellar classification * Haplogroup O3 (Y-DNA), a Y-DNA Haplogroup *

OpenAI o3 OpenAI o3 is a reflective generative pre-trained transformer (GPT) model developed by OpenAI as a successor to OpenAI o1 for ChatGPT. It is designed to devote additional deliberation time when addressing questions that require step-by-step log ...

, an artificial intelligence model

Music

* ''O₃'', the 1993 debut album by the techno band

Sunscreem Sunscreem are a techno/house music band from Essex, England that scored a number of hits on the US Hot Dance Music/Club Play chart throughout the 1990s and into the 21st century. Sunscreem also has the rare reputation as a techno-based band th ...

* ''

O3 A Trilogy Dominici was a progressive metal band formed in 2005 by former Dream Theater vocalist Charlie Dominici. History The band's only released work to date is the ''O3 Trilogy'', a series of three concept albums about the story of a terrorist sleepe ...

'', a 2008 concept album trilogy by progressive metal band Dominici * ''O3'' (album), a 2008 album by Son of Dave

Military

* O-3, a uniformed services pay grade of the United States for the following: **

Captain (United States O-3) Captain in the U.S. Army (), U.S. Marine Corps (USMC), U.S. Air Force (USAF), and U.S. Space Force (USSF) (abbreviated "CPT" in the and "Capt" in the USMC, USAF, and USSF) is a company-grade officer rank, with the pay grade of O-3. ...

, in the Army, Marine Corps, Air Force, and Space Force **

Lieutenant (navy) LieutenantThe pronunciation of ''lieutenant'' is generally split between , , generally in the United Kingdom, Ireland, and Commonwealth countries, and , , generally associated with the United States. See lieutenant. (abbreviated Lt, LT (U.S. ...

, in the Navy, Coast Guard, Public Health Service Commissioned Corps, and NOAA Commissioned Officer Corps * USS ''O-3'' (SS-64), a 1917 United States O class submarine

Transportation

Oldershaw O-3 The Oldershaw O-3 is an American high-wing, single seat, V-tailed glider that was designed by Vernon Oldershaw. Two examples were constructed as gliders and then both were later converted to motor gliders.Said, Bob: ''1983 Sailplane Directory ...

, a glider *

Otoyol 3 Otoyol 3 (), also known as the European Motorway () and abbreviated as the O-3 is a long otoyol in East Thrace, Turkey. The O-3 runs from Edirne to Istanbul and is the only motorway in Turkey located entirely in Europe. The motorway begins west ...

, a Turkish motorway from Edirne to Istanbul *

LNER Class O3 The Great Northern Railway (GNR) Class O1 was a class of two-cylinder 2-8-0 steam locomotive designed by Nigel Gresley for heavy freight work and built by the GNR between 1913 and 1919. History Gresley designed the O1 2-8-0 for the heavy coal ...

, a class of British steam locomotives

Other uses

* Oskarshamn 3, unit 3 at

Oskarshamn Nuclear Power Plant The Oskarshamn Nuclear Power Plant is one of three active nuclear power stations in Sweden. The plant is about north of Oskarshamn, directly at the Kalmarsund at the Baltic Sea coast and with one active reactor, producing about 10% of the elec ...

in Sweden

Science and technology

Music

Military

Transportation

Other uses

See also