Studies of Two Lynds Bright Nebulae: LBN 140.77-1.42, a Remarkable Thermal Ridge, and LBN 139.57+2.70, a Radio and Infrared Partial Ring
Abstract
Observations at 408 MHz of two extended features corresponding to objects in Lynds' (1965) catalog of bright nebulae are presented. These are LBN 140.77 - 1.42, which corresponds to a linear radio ridge roughly 2 deg in extent that is approximately perpendicular to the Galactic plane, and LBN 139.57 + 2.70, which shows a partial radio ring roughly 12 arcmin in radius. The radio emission from LBN 140.77 - 1.42 has a thermal spectrum, and it coincides with the western edge of a large 'spur' that is evident in atomic hydrogen in the Perseus arm. Part of this 'spur' is also evident in the infrared at all IRAS wavebands. Thus, LBN 140.77 - 1.42 appears to be a remarkably large-scale ionization front penetrating a large interstellar cloud. The nature of LBN 139.57 + 2.70 is not clear.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 1989
- DOI:
- 10.1086/115290
- Bibcode:
- 1989AJ.....98.2210G
- Keywords:
-
- Infrared Spectra;
- Nebulae;
- Radio Spectra;
- Astronomical Catalogs;
- Astronomical Spectroscopy;
- Emission Spectra;
- H Ii Regions;
- Infrared Astronomy Satellite;
- Radio Telescopes;
- Astrophysics;
- NEBULAE: GENERAL