Rho Ophiuchi
An image of the Rho Ophiuchi dark cloud taken with ISOCAM
The scattered
bright dots are new stars of moderate size, comparable in mass to the Sun. The
bright fuzzy object, upwards and slightly to the right of centre, is a new
massive star, much heavier than the Sun, still wrapped in the placental cloud
from which it formed. A similar object appears partly veiled towards the
bottom right of the picture. The conspicuous wisp right of centre is the
interface betweeen the dense cloud and the general interstallar medium. In a
dark region near the centre of the picture the dust is so dense that even an
infrared telescope can look no further into the murk. The image is a colour
composite of data taken at wavelengths of 7 and 15 microns of an area of sky
approximately 0.75 x 0.75 degrees.
The high
angular resolution and sensitivity of the ISOCAM observations
have revealed several previously unknown characteristics of the mid-IR
diffuse emission: the small scale filamentary structure (thickness 0.03
pc) of the emission at the illuminated edge of the molecular cloud, the
sharpness of color variations at cloud edges, the barely resolved
filamentary structure of the dust emission surrounding a bright embedded
source, and several dense cores seen as sharp and deep absorption
structures against the diffuse cloud background.
Rho Ophiuchi has been the subject of both a recent Astronomy and Astrophysics Letter;
"ISOCAM mapping of the rho Oph main cloud"
Abergel, A. et al. and a press release from the ISOCAM consortium;
"The Earth's Closest Star Nursery"