Lambda Centauri Nebula (2)

IC 2948, Caldwell 100

Magnitude:  +4.5Diameter: 8.5 light years.
Apparent size: 75 x 50 arc minDistance: 6,500 light years.
Constellation: CentaurusType: emission nebula

The Lambda Centauri Nebula, Caldwell 100 has two regions, which together extend outside my telescope field of view. The above image is of the region known as IC 2948. The other region extends beyond the top of this image and is known as IC 2944, which I imaged in March 2021.

As I stated then, the nebula is noted for its Bok Globules – small dark regions, 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.

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”.

Here again is the cropped image of some of the Boks which I published in March:

The weather prediction is for clear skies tomorrow evening, so it’s looking good for the total lunar eclipse, which will last for eighteen minutes, so hopefully a few images to be obtained for my next post!

Feature Image Details

Feature image date:2021-05-22.
Exposure:152 min (41 x 223 sec frames).
Field of View:1.54° x 1.01° (up is 48.8 degrees E of N).

Where is C100 in the sky?

Location of C100 in Centaurus.
Location of Centaurus constellation in the whole sky map.

If the Astrometry images do not appear it is because the Astrometry website is sometimes off line.

Telescope Details

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


  1. Great images! It must be impressive to see.
    I’m calling this eclipse the “crying moon eclipse”.
    First, because the Moon sets here in New York before the partial phase begins.
    Second, the Moon is so close to the edge of the umbra, that limb of the Moon will be dark, but much brighter than the rest of the Moon nearer the center of the umbra. The first lunar eclipse I ever saw was like this one. I was about ten years old and got fooled by the bright edge, thinking I didn’t get to stay out long enough to see the total part of the eclipse when my parents called me in for bedtime. I cried. Sorry, Mom and Dad!
    It might be good to point this out about this eclipse, so people aren’t disappointed. This ‘edge’ eclipse will be very special for those who see it.

    Liked by 2 people

    1. Nice story but I’ll stick with calling it a “lunar eclipse”!
      You are right, it’s not a smack-on centre eclipse, so we might expect some edge brightening.


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