An Etymological Dictionary of Astronomy and Astrophysics

English-French-Persian

فرهنگ ریشه‌شناختی اخترشناسی-اخترفیزیک

Homepage  Preliminaries  Abbreviations  Acknowledgments  References 
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
dark cloud
  ابر ِ تاریک  
abr-e târik (#)
Fr.: nuage sombre  

A relatively dense cloud of → interstellar gas, mainly molecular, whose dust particles obscure the light of stars behind it. A famous example is the → Horsehead Nebula silhouetted against the reddish glow of the → H II region IC 434. Individual dark clouds come in a range of sizes from tens of → light-years to tiny → Bok globules of only a few thousands → astronomical units.

See also: → dark; → cloud.