Astronomers believe that our Solar System formed some 4.5 Billion years ago from a protoplanetary disk that surrounded our Sun when it was in it’s infancy. This disk was comprised of gas and dust, most likely remnant material from a earlier nova or supernova. The gas and dust eventually coalesced into planetesimals, protoplanets, and eventually into the 8 planets of our solar system. The rest of the gas was blown away into interstellar space. Today, to see a model of what may have occurred 4.5 billion years ago, we need only take a look at the heart of the Orion Nebula, M42. This greatest of all stellar nurseries within our view, has about 700 stars at differing levels of maturity, and about 120 “Proplyds” (Protoplanetary disks). The Hubble telescope has identified these “Proplyds”, which suggests that the formation of solar systems like our own is a fairly common phenomenon.
In the image above, M42, the Great Orion Nebula takes center stage. It is one of the most photographed and studied objects in the Heavens. It lies about 1200 light years from us, is 24 light years across, and is visible to the naked eye, making up the center object of Orion’s Sword, which hangs southeast of the well known Belt. It is part of the much larger Orion Molecular Cloud Complex that stretches northward enveloping the Horsehead and Flame Nebulae as well as Barnards loop. M43 is the small HII region separated from M42 by a strong dust lane. NGC1977 can be seen north (to the left in this image) of M42/43 and is also called the “Running Man Nebula”. At the heart of M42 lies the Trapezium, a collection of 4 (6 actually, if you count the 2 binary stars of this asterism) extremely young hot O class stars that generate a lot of ionizing energy and turbulent stellar winds.
If one looks carefully, a green hue can be seen surrounding the Nebula. This puzzled astronomers for years. In fact, in the early part of the 20th century, scientists believed that a mysterious new element called “Nebulium” was the source of this eerie green hue. It is now know to be caused by a low-probability electron transition in doubly ionized oxygen. O-class stars within the region create ionizing radiation and the red hue that is visible. The blue is reflected radiation from the same stars.
Image Acquisition information:
Date: December 2007
Location: Starlodge Observatory
Telescope: FSQ 106
Camera: STL 11000
LRGB: 50:60:60:60 (600 second sub-exposures). All color data was added to luminance as well. 5:5:5:5 (30 second sub-exposures for trapezium area). 70 minutes of Ha data was also added to the Luminance.