The Prawn Nebula
|Exposure time: |
|Field of view: |
90.4 x 59.4 arc minutes
The Prawn Nebula is a colossal star-forming emission nebula in the southern constellation of Scorpius, seen here in the characteristic red of H-alpha. It consists mainly of glowing hydrogen gas, excited by intense ultra-violet radiation (the same kind of radiation which gives us sunburn) emitted by the many hot new-born stars that reside in and around the nebula. It also contains some dark and clumpy dust clouds.
Other object classifications in this region include the open clusters Collinder 316 and Trumpler 24; and NGC 6231 (the small open cluster to the far right).
There seems to be some debate about the distance of IC 4628. Sky Safari lists its distance as an unusually precise 2,707 light years, whilst ESO lists it as 6,000 light years. That’s quite a difference, so take your pick.
At three hours and one minute, this is the longest exposure that I have ever taken, so, out of interest, here is a screen shot of the SharpCap software interface which I was twiddling and tweaking for three hours to capture, live stack and pre-process the above image:
Finally, does the Prawn Nebula really look like a prawn? Yeah. Naaah.
To the left hand side I see the head of a farm animal – but mostly I just see a helluva load of hydrogen gas spread across a diameter of 70 light years. There are whole globular clusters that size!
Cosmic Focus Open Observatory
Above us only sky….
|Scope:||SkyWatcher Esprit 120 mm apochromatic 3-element refractor; 840 mm f/l @ f/7.|
|Optics:||Field flattener; ZWO duo narrowband Ha + [OIII] filter.|
|Mount:||SkyWatcher EQ6-R Pro mount.|
|Camera:||ZWO ASI 071 MC cooled.|
Thanks for reading!
Images © Roger Powell
I’m one of the founder members of Macarthur Astronomical Society.