IC 2944, Caldwell 100
|Magnitude: +4.5||Diameter: 8.5 light years.|
|Apparent size: 75 x 50 arc min||Distance: 6,500 light years.|
|Constellation: Centaurus||Type: emission nebula|
I attempted the Running Chicken Nebula two years and made a hash of it. This one is a bit better. It is dominated in the centre by the very bright foreground star Lambda Centauri (420 light years distant) and surrounded by a huge emission (6,500 light years distant). Hence the nebula is often also referred to as the Lambda Centauri Nebula.
It’s a whopper. Compared to the Sun, it is twice as hot; ten times the diameter; and it’s luminous output is 1280 time greater. It has a dim companion star of magnitude +11.5.
……..Bok, Bok, Bok
There are two regions to the Running Chicken Nebula : IC 2944 on which the feature image was centred; and IC2948 which is towards the top. Here is an enlarged cropped version from the top my image:
Q. What are those black things?
A. They are small dark nebulae, embedded in dense molecular hydrogen nebulae and cosmic dust. It is within such regions, where the surrounding nebula is condensing, that star formation processes begin. Astronomers call them Bok Globules.
According to Wikipedia, Bok Globules “typically have a mass of about 2 to 50 solar masses contained within a region about a light year or so across”.
“They contain molecular hydrogen (H2), carbon oxides and helium and around 1% (by mass) silicate dust”.
Bok globules most commonly result in the formation of double or multiple star systems.
|Feature image date:||2021-03-04.|
|Exposure:||75 min (19 x 239.6 sec frames).|
|Field of View:||1.59° x 1.06° (up is 196 degrees E of N).|
Where is C100 in the sky?
If the Astrometry images do not appear it is because the Astrometry website is sometimes off line.
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Field flattener; ZWO Duo-band Hα (656nm) and [OIII] (500nm) filter.|
|SkyWatcher EQ6-R Pro mount; ZWO ASI120 guide camera.|
|Imaging camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx).|
|Software: Telescope control: Cartes du Ciel, EQMOD, PHD2, Imaging: SharpCap, Gimp.|
|Observatory location: 34° South.|
Images © Roger Powell
I’m a founder member of Macarthur Astronomical Society