nebula | is a part of gas | ![2001-09-27 09:32:19.0 2001-09-27 09:32:19.0](facet.gif) |
has catalog nebula catalog | ![2001-09-27 09:30:10.0 2001-09-27 09:30:10.0](facet.gif) |
has definition The term "nebula" was previously applied to all kinds of hazy patches in the sky, many of which are now recognized to be clusters or galaxies. (See also diffuse nebula, gaseous nebula, dark nebula.) | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:10.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:10.0](facet.gif) |
has definition Indistinct, nonterrestrial objects visible in the night sky. "Bright" nebulae glow with light emitted by the gas of which they are composed ("emission" nebulae) or by reflected starlight ("reflection" nebulae) or both. "Dark" nebulae consist of clouds of gas and dust that are not so illuminated. "Planetary" nebulae are shells of gas ejected by stars. Spiral nebulae are galaxies. | ![has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:10.0 has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:30:10.0](facet.gif) |
has definition An irregularly shaped cloud of interstellar gas or dust whose spectrum may contain emission lines (emission nebula) or absorption lines characteristic of the spectrum of nearby illuminating stars (reflection nebula). | ![has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:10.0 has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:30:10.0](facet.gif) |
is a kind of celestial body | ![2001-09-27 09:30:10.0 2001-09-27 09:30:10.0](facet.gif) |
celestial body | has spectra | ![2001-09-27 09:30:09.0 2001-09-27 09:30:09.0](facet.gif) |
physical object | has location or center of gravity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has angular momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has mass | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has velocity | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has momentum | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has temperature | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has volume | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has extent | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |
has material | ![2001-09-27 09:27:27.0 2001-09-27 09:27:27.0](facet.gif) |