Thursday, April 2, 2026

The Rosette Nebula

Two days later on 20th March 2026 (one day after new moon) were were continued to be blessed with clear skies and I was able to observe the large Rosette Nebula in Monoceros. This lies a little below (i.e. south) of the Cone Nebula and Christmas Tree Cluster I had observed a few days before. This is what I obtained after 272x15s (68 minutes) on the Dwarf 3:-

 

The first frame was taken at 20:58 UT and the last at 22:56 UT (midpoint 21:42 UT). Here the gain was 60 and duo-band filter employed in the Dwarf 3. Processed in Stellar Studio (auto settings). The image has been binned x2 and the gain and saturation have been increased in Photoshop. 

In the centre of the nebula is a young cluster of stars (NGC 2244, also called Caldwell 50) and these bright stars are illuminating the surrounding nebula (NGC 2239, Caldwell 49). UV light from these stars is ionising hydrogen gas in the nebula and causing the atoms to emit a prominent red line (H alpha) on recombination.  Also seen in this image are denser areas of dust and gas silhouetted against the brighter nebula. These are called Bok Globules and these can be sites where new stars are in the process of being formed.

All text and images © Duncan Hale-Sutton 2026 

Hickson 44 (Leo Quartet)

On the same evening I observed M81 and M82 (the 18th March 2026), I had a go at observing the Hickson 44 galaxy group (also known as the Leo Quartet). These galaxies also appear in the Arp catalogue as Arp 316. What I hadn't anticipated was how small a group these galaxies appear as. Here is the result of 237x15s of observation (just short of an hour) with the Dwarf 3:-

 

The group can be just about made out in the centre of this image. The first frame was taken at 20:36 UT and the last at 21:51 UT. The gain was 60 and the astro filter was employed. Auto settings were used in Stellar Studio (you can click on this image to obtain a larger view). The image has been binned x2. Here is a cropped version of the full size image showing the galaxies in more detail:-

 

Here I have increased the colour saturation and sharpened the image in Photoshop. Moving from left to right we have; the elliptical galaxy NGC 3193 which looks rather stellar like; then the larger edge on spiral galaxy NGC 3190 with its warped central dust lane; above this is the smaller NGC 3187 where again gravitational interaction with other galaxies has stretched its spiral arms into tidal tails; and finally at the bottom right is the barred spiral NGC3185.

All text and images © Duncan Hale-Sutton 2026