Luminous efficacy — is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source s output, or it can be the total electric power consumed by… … Wikipedia
glowing gas — švytinčiosios dujos statusas T sritis fizika atitikmenys: angl. glowing gas; luminous gas vok. Leuchtgas, n rus. светящийся газ, m pranc. gaz lumineux, m … Fizikos terminų žodynas
List of most luminous stars — Below is a list of stars arranged in order of decreasing luminosity (increasing bolometric magnitude). Accurate measurement of stellar luminosities is quite difficult in practice, even when the apparent magnitude is measured accurately, for three … Wikipedia
Coal gas — Towngas redirects here. For the company in Hong Kong trading as Towngas , see The Hong Kong and China Gas Company Limited. See also: Coal gasification and Coal seam gas Coal gas (also town gas and illumination gas) is a flammable gaseous… … Wikipedia
Neon sign — … Wikipedia
Chromosphere — The Sun observed through a telescope with an H alpha filter … Wikipedia
Orion Nebula — The entire Orion Nebula in visible light. Credit: NASA/ESA Observation data: J2000 epoch … Wikipedia
sun — sunlike, adj. /sun/, n., v., sunned, sunning. n. 1. (often cap.) the star that is the central body of the solar system, around which the planets revolve and from which they receive light and heat: its mean distance from the earth is about 93… … Universalium
planetary nebula — Astron. an expanding shell of thin ionized gas that is ejected from and surrounds a hot, dying star of about the same mass as the sun; the gas absorbs ultraviolet radiation from the central star and reemits it as visible light by the process of… … Universalium
Orion (constellation) — For other uses, see Orion (disambiguation). Orion Constellation List of stars in Orion Abbreviation Ori Genitive Orionis … Wikipedia