Monoceros Loop

Monoceros Loop

[mə′näs·ə·rəs ′lüp]
(astronomy)
A filamentary loop nebula about 1000 parsecs (2 × 1016 miles or 3 × 1016 kilometers) distant, which is the remnant of a supernova that took place 50,000-100,000 years ago.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.