Hickson 40 - Faulkes Telescope North

Hickson 40 (also cataloged as ARP321) is a fairly bright compact group of galaxies 300 million light years away in Hydra. The brightest component (HCG40a) is around magnitude 12, and the faintest (HCG40e) around magnitude 17. Again, this group contains a nice mix of sprial and elliptical galaxies and was imaged by the 8.2m Subaru telecope and shown on APOD 8 years ago. Although we didn't get as deeper image as the Subaru, it does have 16 times the light gathering power! Still, you can easily disern the main spiral galaxies in the cluster.

This is the second image from the Faulkes Hickson Compact Galaxy set - please see the previous post below for more details about the Hickson catalog and Faulkes telescope in general.


3 sets of 120 second images were registered and stacked for each of the RGB channels. A pseudo luminance image was created by stacking the calibrated RGB frames and then more agressively processed and recombined back into the final LRGB composite.

Hickson 37 - Faulkes North Telescope

In the '80's, Paul Hickson created a catalog of compact galaxy groupings that he used to study galactic evolution and gain the first evidence for that elusive material - dark matter. The Bristol Astronomical Society has been working with the Faulkes Telescope to image parts of the catalog in detail that only a research grade telescope and CCD camera can do justice.

This image is of Hickson 37 - a grouping of 5 galaxies (though a few more are visible on this image). I trawled the internet to try to find images of this grouping, but the best I found was from the Space Telescope Science Institute (STScI) Digital Sky Survey plates. A direct link can be followed here if the hyper link works, else can be searched for using its SIMBAD name of HCG37, and the POSS2/UKSTU Red plate here.

A set of 3 frames per channel (RGB) were taken, each of exposure 240 seconds, using the 2m F/10 Ritchey-Chretien Faulkes North telescope situated atop Haleakala on the Hawaiian island of Maui. These were then registered and processed with the fabulous free Iris image processing application, and PixInsight.


You can see a nice cross section of different types of galaxies here - from elliptical to spiral to barred spirals. I'm rather fond of the side-on sprial HCG37b - the dust lanes are quite exquisite in their detail! The biggest elliptical, HCG37a, is also known as NGC2783 and has a magnitude of around 13. This gives an insight in not only the faintness of the Hickson cluster members, but also the sensitivity the Faulkes Telescope CCDs.

The classification of the galaxies in the cluster for the annotation were located here, although there is no mention of the 2 small, almost perpendicular galaxies just to the side of HCG37a - incidentally they are only just visible on the DSS plates. I tried to ID these using various star charts to find their designations and magnitudes, but I could not find any mention of them. If anyone can shed some light on them, please do!

Constellation Tour

I've been having fun with my Canon 10D DSLR lately, using just a simple tripod and 28mm SLR lens (which is probably more like 40mm as it's a lens from an old 35mm camera). With this set up, one can easily take exposures of 15-30 seconds without noticeable trailing, only depending on how close to the celestial equator the target is. I rather like this sort of wide field imaging as not only is it really easy, but it also really helps you find your way around the sky during the different seasons of the year - a must when you start looking for more specific objects and comets.

The first target was good old Orion, taken from my back yard in the centre of the city - so plenty of light pollution to combat! The results were quite surprising - especially when compared to the images I took at my Dark Site ... but i'll get onto that in a minute! This was a stack of 15 second images that needed heavy gradient removal to get a flat background due to sodium light below, and near full moon glow from the left.

Compare this to an image taken from my dark site below - there's not a lot of difference, but I put that down to the full moon present when they were taken. It might have helped being 2am on a very cold night ... it's amazing how your patience can be so tested at late hours and cold temperatures!

Next up was the home of a good few Messier objects - Auriga. Whilst easily discerned with the naked eye and bright moon light, once captured and processed it becomes another story! The image has a myriad of stars that can be quite confusing at first, and was the reason I decided to place annotated images next to the originals. Personally, I find doing this helps me learn my around both constellations and the night sky itself.



Just around the corner from Auriga is the constellation of Perseus. This contains one of my favorite binocular objects in this part of the sky - MEL 20 (Cr39) - a wonderful open cluster containing a good few dozen stars. Situated in the centre-top of the main body of Perseus, it fills the view of 10x50's perfectly. It's a real jewel so be sure to check it out!



Last stop on the tour is Taurus, the Bull. With the wide field of view provided by the 10D and 28(40)mm lens, this also incorporates the famous Pleiades - M45. Again, the rich field of stars on a photograph can hide the shape on Taurus, but in this case the bright red "eye" of the bull, Aldebaran, is quite apparent.



Hopefully I've inspired you to go out and have a go with your own digital camera. All you need is to be able to manually set the exposure to as long as possible, and set the focus to infinity. If you can't do the latter, try pointing the camera towards a distant object to get it to focus. Keeping the half-depressed shutter button down, turn the camera back to the area of sky you wish to take and press down fully. Use a hat or similar to cover the lens as you press to stop capturing camera shake as you let go of the button if you don't have a timer on the camera.

Go on ... have a go :)