 |
CHAMÄLEON + ONJALA OBSERVATORY DeepSky | SITEMAP HOME CHAMÄLEON |
|
 |
|||
| « back to overview
Cluster « back to overview nebulae |
Load
higher resolution (1800 x 1200 Pixel 3500 x 2300 Pixel) |
Object description |
Sharpless 2-86 (also GN 19.43.1) is a very faint H-II emission region covering more than 2 x 1 degrees in the constellation Vulpecula. It is a typical star-forming region, and about 50 massive concentration centers of 15 to 70 solar masses have been observed inside the hydrogen cloud using submillimeter observations, enough mass to allow many more new stars to form. The dark cloud in the core region has the popular name "the snorkel".
In the center of the nebular region is the open star cluster NGC 6823, whose hot blue stars provide the ionization energy to make the hydrogen gas glow red. The stars certainly have an age of only a few million years. The cluster is assigned to class I 3 p n according to Shapley and has about 100 members. The distance to the solar system is estimated to 6 000 lightyears and about its apparent diameter of 12 arcminutes this results in a true diameter of about 50 lightyears. NGC 6823 was discovered by Friedrich Wilhelm Herschel on July 17, 1785.
 |
NGC 6820 is classified as a diffuse nebula, but
could also be a supernova remnant or a small reflection nebula. It was
discovered long after Herschel on August 8, 1864, by German astronomer Albert
Marth, who observed with a 48-inch telescope as William Lassel's observer at
Lassel's private observatory in Malta. Marth is a rather unknown name in
classical astronomical history, although he is credited as the discoverer of
nearly 600 objects in the NGC catalog. In 1882 he participated in the Venus
transit expedition to the Cape of Good Hope, and the lunar crater Marth and the
Martian crater Marth are named after him. The lunar crater Marth is one of the
very rare concentric double craters in Palus
Epidemiarum. « Click here or the thumbnail to load a large annoted image and a size comparison to the full moon. |
 |
 |
 |
 |
 |
 |
 |
| Sun | Moon | Solar System | DeepSky | Widefield | Miscellaneous | Spec. Projects |