LDN 637 is a
strongly segmented dark and molecular cloud complex in the constellation Eagle,
in the middle of the so-called "Aquila Rift", a dark region of the Milky Way,
which is full of dark clouds. The dense clouds are about 300 to 600 light-years
from the solar system and spread over a true area of about 10 light-years.
In two places the dust clouds reflect the light of nearby stars. One is
GN 19.18.0 and the other is HH 32, a variable T Tauri star. These objects are signs
of just active star formation. They are associated with compact emission
nebulae (Herbig-Haro objects).
Read more at this URL. And here are images and information about HH 32, taken with
the Hubble Space Telescope.
catalog designation LDN 673 comes from the "Lynds'
Catalogue of Dark Nebulae" compiled by astronomer B.T. Lynds in the
early 1960s. His catalog included over 2000 gas and dust clouds within the
These galactic gas and dust clouds are not to be
compared with terrestrial clouds in the earth atmosphere. By terrestrial
standards, the density of galactic clouds is more like a vacuum. Nevertheless,
they are dense enough to completely block the light from stars behind them. The
LDN 763 complex of dark clouds contains up to one million solar masses of
matter. Enough matter to form new stars and star clusters.
« Click here or the thumbnail to load a large annoted image
and a size comparison to the full moon.