May | 2026 | WATCH THIS SPACE(MAN)

Continuing the galaxy season theme, I returned to image Messier 106 last month, one of the brightest galaxies in the northern sky. Located about 24 million light-years from Earth in the constellation Canes Venatici, it is similar in size and luminosity to the much closer Andromeda Galaxy (2.5 million light-years), which therefore appears much larger. Classified as an active Seyfert galaxy, M106’s core contains a supermassive black and thereby, energetic activity produces unusual arms made of hot glowing gas, which is only visible in radio and X-ray wavelengths.

The region around M106 is also very rich with other galaxies, I counted many more. One close companion is NGC 4248, a smaller irregular galaxy gravitationally linked to M106. Nearby in the same field is NGC 4217, an edge-on spiral galaxy appearing thin and elongated through telescopes. More distant background galaxies such as NGC 4220, NGC 4231, and NGC 4232 can also be seen in deep astrophotography images, giving the area a crowded and dramatic appearance.

It’s been six years since my first and only image of M106, which can be see here. At the time I was thrilled to capture this exciting galaxy but this time the Bortle-4 sky of Somerset has unveiled much more detail and colour than before; it’s always good to see progress with my imaging. Notwithstanding, it was something of a shock that after pre-processing the data using PixInsight’s WBPP calibration and stacking software, the High Rejection from the luminance revealed numerous satellites that had passed overhead, which does not bode well for astronomers in the future!

FOOTNOTE:

After publishing this image in Stargazers Lounge, a number of people commented that there were a lot more galaxies in this image than I had initially suggested (x7). I therefore returned to Pixinsight and with Image Solver + Annotate Image (which included the main catalogues & added the Principal Galaxy Catalogue), created a more detailed illustrated image shown below. This indicates there are 109 galaxies in the image! Now I really feel even smaller.

IMAGING DETAILS
Main Objects	M106 etc
Constellation	Canes Venatici
Distance	24 million light-years
Size	18.6’ x 7.2’ actual diameter approx. 135,000 light years
Apparent Magnitude	+8,4

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma HLRGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 12:18:20.84 DEC +47:16:25.3 North = Bottom Left
Exposures	Ha x 8 X 600 Sec + L x 43, RGB x14 each @ 300 sec Total Integration Time: 8hr 25min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 600 sec & 5 x 300 sec Darks + 20x Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Bortle 4
Date & Time	8^th 9^th 12^th & 13^th April 2026 @ +21.30h
Weather	Approx. <6^oC RH >=>70% 🌙 <= 65% to 30% waning

Who doesn’t wonder at the majesty of galaxies and what might exist therein? Unfortunately, with a few exceptions my astrophotography equipment struggles to image most of these beguiling objects of the night sky; galaxies are very, very big but also very far away and thereby, very small from our perspective on Earth. Notwithstanding, the so called ‘galaxy season’ runs from March to May and now being in the darker Bortle 4 skies of Somerset it seemed the right thing to do this year.

In this case NGC 2403, a mid-size spiral galaxy with an apparent magnitude of about 8.9, the 11^th brightest in our sky, it is just bright enough for small to mid-sized telescopes and benefits more from darker skies than focal length. Its oblique orientation reveals a wealth of structures: loosely wound spiral arms, over 100 prominent H II regions, a mottled core but lack of distinct dust lanes, not unlike the Triangulum Galaxy M33 in many ways (see close-up image below).

NGC 2403 is in the northern constellation Camelopardalis, approximately 10 million light-years away from Earth, and a member of the M81 Group of galaxies. Numerous bright star-forming regions and nebulae can be observed throughout its spiral arms, which are highlighted in the final image by the addition of Ha wavelength data. One of the most notable features of NGC 2403 is its abundance of supernova remnants, indicating a high rate of stellar birth and death, of which SN 2004dj was a particularly famous event.

This was a difficult object to image and process but helped by Somerset’s excellent dark skies, I was pleased with the result.

IMAGING DETAILS
Object	NGC 2403
Constellation	Camelopardalis (Giraffe)
Distance	10 million light-years
Size	21.9′ × 12.3′ or 50,000 light-years
Apparent Magnitude	+8.9

Scope	William Optics GT81 + Focal Reducer FL 382mm f4.72
Mount & Control	ZWO AM5 + ASIair
Guiding	William Optics 50mm guide scope
	+ ZWO 120MM Mini
Camera	ZWO ASI294MM CMOS sensor
	FOV 2.87^o x 1.96^o Resolution 2.50”/pix Max. image size 4,144 x 2,822 pix
EFW	ZWOx8 EFW & 31mm Chroma Ha, OIII, SII 3nm & RGB filters
Capture & Processing	ASIair, Deep Sky Stacker & PixInsight v1.9.3 Lockhart
Image Location & Orientation	Centre = RA 07:37:02.68 DEC +65:35:45.5 Bottom Right = North
Exposures	L x13 @ 600sec + R x10, G x10, B x10 @ 300sec + Ha x10 @ 600sec Total Integration Time: 6hr 20min
	@ Gain 120 & 30 Offset 21 @ -15^oC
Calibration	5 x 600 sec & 5 x 300sec Darks + 10 x Ha LRGB Flats & Dark Flats @ ADU 32,000
Location & Darkness	Castle Farm Observatory, Wookey, Somerset – UK Typically Bortle 4
Date & Time	5^th 6^th 8^th April 2026 @ +21.30h
Weather	Approx. <5^oC RH >=<60% 🌙 approx. 90% to 80% waning moon