The results of a brief real time video observing session last night.
First up is a very feint Horsehead Nebula in Orion. An impossible visible target from the light polluted skies of London but within reach with a 30sec video exposure using a Lodestar Colour camera and the free Lodestar Live software.
The Horsehead Nebula is one of the most famous nebulae on the sky. It is located to the south of Alnitak the Eastern of the 3 stars in Orion’s belt. This dark cloud of molecular dust is about 1500 Light Years from Earth.
The Horsehead shape is just about visible as the dark indentation to the red emission nebula behind. The Horsehead is dark because it is an opaque molecular dust cloud that lies in front of the bright red emission nebula. The Horsehead is a stellar nursery and within it many young stars are forming as the dust and gas coalesce through gravity and begin the process of star formation.
Next is the Great Nebula of Orion M42 is an emission and reflection nebula, illuminated by hot luminous stars emitting high energy ultra violet radiation. Located in the sword of Orion, M42 is the closest and most prominent star formation region to Earth (about 1500 light years distant). Again an area of massive star formation within immense molecular clouds of gas and dust with some 700 stars in various stages of star formation. The nebula is about 30 light years across. The bright area at its very centre is a very young open cluster of stars known as the trapezium cluster. M42 is thought to contain the mass equivalent to 2000 Suns. The smaller M43 or Flame Nebula is to the upper right in the image below.
Click on the artist impressions below showing the location of the Orion Nebula in relation to our Sun/the Solar System and the rest of the Milky Way.
Lastly, Hubble’s Variable Nebula NGC 2261.
This peculiar object is located in the constellation of Monoceros, to the East of Orion. Discovered by W Herschel in 1783.
This is an emission and reflection nebula that is enveloping the erratic variable star R Monocerotis and is at a current visual Magnitude of 10.0. The variable nature of the brightness was first noted by Edwin Hubble in 1916 from a series of photographs. The unpredictable variation is thought to be due to shadows cast by the dense regions of dust passing by the star at its tip which cannot be seen directly and the light is only visible as the scattered light reflecting on dust particles in the surrounding molecular cloud.
Hubble’s Variable Nebula is about 3000 Light Years away. The cone shaped nebula is about 3 Light Years long and 1.5 Light Years across. The variable star R Mon is a very young star some 300,000 years old, of a mass of 10x our Sun and has the illumination equivalent to 80x that of our Sun.
For comparison is an image of the Hubble Variable Nebula taken using the Hubble Space Telescope: