A Bunch of New Targets
I was able to get out for a couple imaging sessions earlier this month during the moonless night period following Full Moon heading up to first quarter.
While I still have a lot of work to do to arrive at a truly solid equipment setup and procedures that are bulletproof, I have managed to shoot a couple things before I lost them in the western glare for the year. The amazing number of galaxies in Leo and Virgo have been a theoretical target of mine and in keeping with a theme I seem to be developing of multiple deep-sky objects in the same shot, I decided to capture the combination of galaxy M108 and M97 the "Owl Nebula" just outside the bowl of the Big Dipper.
As a nod towards instant gratification I also re-shot globular cluster M13 with the new better camera and while I was at it I thought, "if you're going to 'Go Big' on star clusters I should get Omega Centauri" which is twice as big as the next largest globular cluster. Star clusters don't seem to be as finicky as galaxies and nebulas do when it comes to processing them later in the computer. Also, they're millions of times closer than galaxies so they almost seem 'easy'...
Marriott's Barony Beach Club where I work on Mondays has always let me take photos and It was my first 'real' photo session since getting the PoleMaster™ polar alignment camera set up and it got me right on the pole on the very first try; I was keen to see what kind of a difference it would make in the blobby or streaky stars I get in photos. You can get those for any number of reasons but not being polar aligned will assure it; so it's the problem you have to solve first.
Mega-Globular Dude!
Here are two star clusters: M13 the famous Hercules Cluster and the almost "lore-like" glob for Northerners, Omega Centauri.
First of all it was really great to get the Omega Centauri pic; I had only been able to see this since moving to Hilton Head in 2015 and to have my own photo of it is very exciting! It was so low to the horizon that if you just stood back and looked at the scope you'd swear it was pointed at the sand dune! We just had one of those nights where it was clear hundreds of miles out into the Atlantic Ocean and we had much clearer than usual low-to-the-horizon viewing.
Omega Centauri is also by far the biggest, brightest globular cluster in the Milky Way. It's also close. It's so much bigger than the next that astronomers always had a to wonder why this one… hmmmm… Then someone found a Black Hole in the center of it! Very unusual because no other Globular has one!
One thing led to another and the current thought is that Omega Centauri is really the "remnant nucleus" of one of our dwarf galaxies that collided with or got waaaay too close to the Milky Way, absorbing all the outlying stars into the general galactic population.
M65 & M66
I seem to be developing a 'thing' for photos of multiple deep-sky objects in a single frame. It started with M81 / M82 which I detailed in another blog post. I haven't seen them much lately but I remembered that M65/66 was a great pair of galaxies to shoot, bright and reasonably close together in the sky. and well placed in the May sky.
I had a major shoot from the Palmetto Bluff area where I was able to do nothing all night but set up and do photography. It was both a big success and a gigantic failure at the same time. I'll explain later. I was able to get a bunch of different objects that night but not like I was intending.
M65 and M66 are about 37 million light-years distant which would put them on the near side of the Virgo Galaxy Cluster.
Open Star Cluster M46
I've always liked this particular cluster, most notably for it's 'value added' approach to being a good galactic inhabitant. Nestled in the outskirts of the cluster one of the stars has a planetary nebula around it; or so it seems but the nebula is actually a line-of-sight kinda thing and not associated with the cluster in physical space.
I caught this one before it slipped to the horizon and I had a good, low western view.
Another 'Two-fer': A Galaxy with a bonus nebula
M108 is an edge-on spiral galaxy just off Merak, one of the bowl stars of the Big Dipper. M97 is a planetary nebula that carries the name the "Owl Nebula".
.I was kind of on the fence about posting this one. At this size it looks pretty good but when I was working on the full resolution image in the computer I noticed how much better my images look in the center of the frame than the edges. This is a symptom of something else in my system that isn't as 'square' as it should be, I'm thinking mirror alignment–I need a better method.
The problem with this photo is because M108 / M97 are near to each other but not that near they end up on the edges of the frame where all the problems are and the middle of the shot looks better but there's nothing interesting there. Honestly this was an experiment to see how much sky I can see with the 10-inch astrograph scope and the new larger-sensor camera which have only been set up a couple times thus far. Seems like I have about one degree field of view in the sky which is about the size of one of your smaller fingernails held at arm's length.
The Heart of the Virgo Cluster: Markarian's Chain.
Well if you like to see more than one deep sky object in your photo you can't do much better than the Heart of the Virgo Cluster. It's the nearest super-cluster of galaxies and encompasses a bubble in space that starts at about 30 million light years and ends at roughly 65 million. At the heart of the cluster is a nice curving progression of galaxies referred to as Markarian's Chain
The giant elliptical galaxies M86 (with it's background companion PGC40659) , M84 and NGC 4402 dominate the image while lots of smaller galaxies are visible or barely identifiable. I count 15 on my master image, see how many you can see here.
This was by far the toughest image to process in the computer; the elliptical galaxies extremities were particularly touchy and to make an image like this work at all it's real hard to do without also bringing up all the digital noise as well. At this resolution it looks pretty good but if you zoom in on the large image there's all kinds of unspoken horrors going on. More things to learn…
Adversity vs. opportunity
Earlier I said while this was ultimately a successful "beginner's shoot" it didn't happen at all the way I planned. I had been planning to take deep, long shots of M65 / M66 and the Virgo Cluster as my only real targets for the night.
Previously I had been limited to a maximum exposure time of about 2 minutes before the images would suffer from one of the myriad of things that can make an astrophoto lousy. One of those was polar alignment of the telescope mount with the Earth's rotational axis which I never actually got perfectly right ever so I thought that now that I had the pole-master camera that I would be finally able to extend that out to perhaps 4 minutes. Right now I'm shooting my photos unguided, just letting the mount do it's own thing and hoping that it tracks the sky well enough until I can get auto-guiding working which is proving to be a 'next-level' capability.
So I shot a 4 minute test exposure and checked it hoping for awesomeness, but instead it looks like a five year old who's off his meds was driving the scope during that shot. So I scaled it back to 2 minutes and it was still horrible and way worse than my other 2 minute exposures even with my cheap mount last year. So I cut it back to a minute, then 30 seconds, then 15 to 20 seconds before I finally saw acceptably non-egglike stars.
I was truly baffled why my performance was so poor but I was not going to go home empty handed so after a couple experiments with the mount settings I decided rather than shoot ten 4-minute images I'd shoot 30 to 60 15-second exposures depending on the object.
These short exposures allowed me to get through with the objects faster and could add things to the night's schedule. So instead of maybe coming away with one or two shots I got 4 from this shoot. Yeah, they're all beginner quality but things are coming together.
I think the problem with the mount was not solid enough power; next time I'm connecting it straight to the car battery which will hopefully get the 5 year old out of my long images.
I've also bit the bullet and bought myself a windows PC for use in the field. I've come to understand that there's this network of drivers and protocols for computers, mounts, cameras, filter wheels, focusers etc. custom developed for amateur astronomers and astrophotographers called the ASCOM environment. When I get it all functioning I should be able to start working on getting the mount to make little adjustments and follow the sky perfectly via auto-guiding and that will truly be the next level.
Exciting times!
Bill the Sky Guy