(of stellar atmosphere)
41Dyson sphere — A Dyson sphere (or shell as it appeared in the original paper) is a hypothetical megastructure originally described by Freeman Dyson. Such a sphere would be a system of orbiting solar power satellites meant to completely encompass a star and… …
42Instability strip — The Instability strip is a nearly vertical region in the Hertzsprung–Russell diagram which is occupied by pulsating variable stars (including RR Lyrae variable, Cepheid variable, W Virginis variable, ZZ Ceti variable, RV Tauri variable, Delta… …
43Titan (moon) — Titan Titan in 2005 by Cassini spacecraft Discovery Discovered by Christiaan Huygens …
44Zeeman-Doppler imaging — In astrophysics, Zeeman Doppler imaging is a tomographic technique dedicated to the cartography of stellar magnetic fields.This method makes use of the ability of magnetic fields to polarize the light emitted (or absorbed) in spectral lines… …
45Europa (moon) — Europa Europa s trailing hemisphere in approximate natural color. The prominent crater in the lower right is Pwyll and the darker regions are areas where Europa s primarily water ice surface has a higher mineral content. Imaged on September 7,… …
46Ganymede (moon) — Ganymede Image of Ganymede s anti Jovian hemisphere taken by the Galileo probe. Lighter surfaces, such as in recent impacts, grooved terrain and the whitish north polar cap at upper right, are enriched in water ice. Discovery …
47Delta Draconis — δ Draconis Location of δ Draconis (left of center). Observation data Epoch J2000      Equinox J2000 …
48Hypergiant — A hypergiant (luminosity class 0) is a star with a tremendous mass and luminosity, showing signs of a very high rate of mass loss. CharacteristicsThe word “hypergiant” is commonly used as a loose term for the most massive stars found, even though …
49Roger Cayrel — Roger Victor Emile Cayrel (born 4 December, 1925, Bordeaux, France) is a French astronomer. His main interests are stellar atmospheres, galactic chemical evolution and metal poor stars.He attended the Lycée Michel Montaigne in Bordeaux and… …
50Coma (cometary) — The comet Ikeya Zhang exhibiting a bright, condensed coma (March 2002) In astronomy, a coma (from the Greek κόμη, hair ) is the nebulous envelope around the nucleus of a comet. It is formed when the comet passes close to the Sun on its highly… …
