The Monkey Head Nebula - NGC 2174

[steppenwolf]

The Monkey Head Nebula 

The Monkey Head Nebula is an HII emission nebula located 6400 light years away in the constellation of Orion. The nebula is associated with an open cluster of mag. +6.8 located at its centre. With a diameter of approximately 40 arcminutes, the nebula is larger than the full Moon. There is much debate over the correct designation of this object as some sources cite the nebula as being NGC 2174 and some stating the nebula as being NGC 2174/5. What is not in contention is that Stewart Sharpless logged this object as SH2-252 in his second and final catalogue completed in 1959. Personally, I go for the nebula being NGC 2174 and the open cluster being NGC 2175!

It was my original intention to produce a bi-colour version of this image but the skies were atrocious and I was running out of time before a major re-shuffle of my gear so just the Ha is displayed here and even then, I only managed to capture 3 subframes before the clouds rolled in (AGAIN!).

Image Stats
Mount: Mesu 200
Telescope: William Optics FLT 98
Flattener: William Optics FR IV
Camera: QSI 683 WSG-8
Filter: Astrodon 3nm Ha
Subframes: 3 x 1800 sec Ha
Integration: 1.5 hours
Control: CCD Commander
Capture: MaxIm DL
Calibration, Stacking and Deconvolution: PixInsight
Post-Processing: PhotoShop PS3

Visually

This target lies 2.3° to the southeast of mag. +3.3 Propus and is a two for one object, comprising an open cluster (NGC 2175) and an emission nebula (NGC 2174) although most astronomers associate the nebula with NGC 2175. Lying in a rich star field, the almost circular shape is punctured by a dent in its western edge which stands out particularly well in images and helps to form the ‘monkey-head’ shape from which the nebula gets its common name. Inboard of this dent towards the east is an area of intense star birth. You’ll need a very large telescope to discern the shape of the nebula but a 4 to 6-inch telescope will show the open cluster very well.

Location of Nebula and associated Star Cluster

RA: 06h09m 36.0s DE:+20°29'00"

Location of the open star cluster NGC 2175

 

Star Birth Region

On the eastern limb there is a dent pushing westward into the nebula and here there is a huge stellar nursery that featured in the Hubble Space Telescope’s IR image (http://hubblesite.org/news_release/news/2014-18) released on 17th March, 2014. The nebula is comprised mainly of hydrogen gas which is ionised by the intense ultraviolet radiation emitted by the hot young stars within the nebula. This ionisation causes the hydrogen to glow red. Also associated with this nebula are some faint regions of reflection nebulosity giving a hazy blue appearance and some relatively faint dust lanes add interest to the interior.

 

I hope you find this of some use as sadly, it will be the last image that I capture using this particular telescope and camera.

[ollypenrice]

Lovely clean result.

Olly