Moulton, Forest Ray, 1872-1952 · New York, The Macmillan company · leaf 359
t distinctive part of the comet, forit is always present and looks much like a circular nebula.Either the nucleus or tail, or both, may be absent, especiallyif the comet is a small one. Comets vary in brightness fromthose which are so faint that they are barely visible throughlarge telescopes to… … Pig. 119. — Brooks Comet, Oct. 19, 1911. Photographed by Barnard at theYerkes Observatory. CH. X, 192] COMETS AND METEORS 313 bright, they are so nearly transparent that faint stars arevisible through them without the slightest appreciablediminution of their light. There are records of about 400…
Astronomy
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
