Planetary nebula, any of a class of bright nebulae that are expanding shells of luminous gas expelled by dying stars. They have a relatively round compact appearance rather than the chaotic patchy shapes of other nebulae—hence their name, which was give
Explore planetary nebulae. Learn the definition of a planetary nebula and understand its structure and chemical composition. Find out how a...
The gas cloud is predominantly made of hydrogen and helium, formed from fusion within the star. What is a planetary nebula and why is it important? Planetary nebulas occur when a dying star ejects its outer layers into space. They play an important role in galactic evolution as they recycle...
An evolutionary relationship between the maximum gas density n ( r ) max and the radius of the ionized segment of the nebula r c is derived. The ionized-gas masses in the envelopes of these nebulae M i / M ⊙ are determined. The relationship between the mass M i / M ⊙ and radius ...
Define Planetary body. Planetary body synonyms, Planetary body pronunciation, Planetary body translation, English dictionary definition of Planetary body. n. 1. a. In the traditional model of solar systems, a celestial body larger than an asteroid or com
nebular hypothesis- (cosmology) the theory that the solar system evolved from a hot gaseous nebula scientific theory- a theory that explains scientific observations; "scientific theories must be falsifiable" cosmogeny,cosmogony,cosmology- the branch of astrophysics that studies the origin and evolution ...
in shaping planetary nebulae, and show that the circumstellar gas is already partly shaped on the AGB, before evolution to the proto-planetary nebula ... N Mauron,PJ Huggins - 《Astronomy & Astrophysics》 被引量: 122发表: 2006年 Determination of the minimum masses of heavy elements in the...
Planetary nebula IC418 (Hubble Space Telescope image), showing the central white dwarf star. The false color image uses the 6584Å [NII] forbidden line (red channel), Hα (green channel), and the 5007Å [OIII] forbidden line (blue channel), similar to Fig. 17.1.Source: NASA and ...
Science Courses / Astronomy 101: Intro to Astronomy Planetary Nebula Definition, Features & Facts - Quiz & Worksheet Video Quiz Course Try it risk-free for 30 days Instructions: Choose an answer and hit 'next'. You will receive your score and answers at the end....
The formation and early evolution of planetary nebulae represent one of the most poorly understood phases of stellar evolution ( Kwok, 1987; Maddox, 1995). One of the youngest, the Stingray Nebula (He3-1357) ( Henize, 1967; Henize, 1976), shows all the tell-tale signs of a newly born ...