Getting ready for something like this is a slow methodical process. Here are some of the steps…
The resort at &Beyond, Sossulvlei
In a stroke of random good luck it appears that I’m going to have my first astronomical southern-hemisphere experience later this year, with both total immersion and fine style! Here’s how it happened…
From time to time I’m hired to give public stargazes at some of the local gated communities both here in the Hilton Head / Bluffton area and also in Savannah. Late last year I was doing one of these at a community called “The Ford” which was Henry Ford’s estate back in the early 20th century and as I understand it, they even manufactured the Model A there for a time even using the local spanish moss as seat cushion padding!.
A couple of the attendees there said to me, “You’re real good with this public stargaze thing, you should check out this resort place we know in Namibia Africa. It’s in the middle of the desert and they advertise their great night sky as an attraction and even have a nice telescope but they need to have people come in to run it since obviously nobody on the resort staff is an astronomer!”
Now I didn’t even know where Namibia even was much less have any desire to go to Africa at all, but I had been looking for an opportunity to see the southern sky. In 2020 I was all set to go the the Oz Sky Star Party in Australia which is an annual week-long event with big telescopes under pristine dark southern skies, fairly deep into Australia in the Southeast area of the continent; more or less inland from Sydney. This trip was booked for March 2020 and we all know what happened about then; and Australia shut the door to all incoming international travel three days before I was to leave! Heartbreaking (and the promoter kept my money too!) Since then I’ve been wondering what kind of astronomical southern sky opportunities there were other than packing up a bunch of gear and booking an AirBnB in the Atacama Desert in Chile!
So I got the name of the resort from them and reached out saying I was interested and after a couple back-and-forths of email I was slated to do 9 weeks there from late July through the end of September!
The resort is run by a company called &Beyond which is an upscale management company that has around a dozen places around Africa, but this is the only one in Namibia. It’s in a location in the middle of the desert and carries the name Sossulvlei although there’s so little out there you would have a hard time even recognizing it as a “town”.
It’s a very upscale, small resort; when it is “jammed to capacity” there are 25 guests on property! My job is to use their fine telescope to show guests fun things in the sky and tell them about the nature of what they’re looking at the same way I do at my stargazes here in Hilton Head.
There is a limit to how much time people are willing to spend at a scope and since it’s winter in the southern hemisphere in August it’ll be getting dark pretty early and after the “crowd” thins out I’ll have the rest of the night to do astrophotography!
So I’m bringing two different photographic rigs with me. They are small enough to travel easily but also good enough quality to get great images. One of them them is a black & white camera with a filter wheel which will get some good wide-field shots of the great, large targets you have in the southern sky. The other rig is a very compact super wide-field rig that can see 7.5 degrees of sky (that’s about 15 full moons shoulder-to-shoulder) and I’m hoping to shoot some wide-field multi-panel mosaics of the Milky Way and the Large and Small Magellenic Clouds down there which will be a new thing for me.
This is going to be an astronomer’s “trip of a lifetime” so check back here for updates and pics as I get them done.
Bill the Sky Guy
July 1st, 2024
The Veil Nebula
The Veil Nebula is one of my favorite objects in the sky and it took a few failed attempts to get it right back in 2019. Unlike a lot of the stuff I post here, you can actually _see_ this with your eyes and a scope (especially if you have an Oxygen III filter on your eyepiece).
I'm not sure what the special allure of this thing is; perhaps the ropy, knotted tendrils of flimsy hydrogen gas, slammed together when the shockwave of a long-ago supernova came ripping through this part of our galaxy.
The Complete Veil Nebula Complex. it's really quite large in the sky, about the width of six full Moons. I took this in 2019 with my widefield camera after getting it wrong at least three times since I started in 2017.
A closeup of the 'hook' end of the Veil which also carries the name “The Network Nebula”.
The Veil is about 2600 light-years away which would be considered fairly close in galactic standards; kinda like 'down the block and around the corner'.
Even still, I'm continually flabbergasted and amazed at the level of detail you can achieve once you have your methods down.
I LOVE this hobby!
I was using a 'travel scope' rig I put together for these astro-glamping trips and this trip was the first real attempt at an image and I'm really happy how it came out considering the sky where I was wasn't all that good being filled with summer moisture and Canadian smoke.
I had a filter on the camera that helps it to see the nebulosity and in this picture, the red stuff is hydrogen and the blue stuff is oxygen.
This Western end of the Veil is often referred to as “the witches broom”!
The new Astro-Glamping setup; I was at the Deerlick Astronomy Village west of Augusta.
This is a great, easy-to-manage travel rig. It's all ZWO cameras and focus motor so I can control the whole thing from an iPad in my chair, drinking a beer!
Astrophoto Blog: The Cave Nebula Sh2-155, a region of glowing hydrogen and dark detail in the Constellation of Cepheus.
The “Flaming Star” Nebula, IC 405
This is The Flaming Star Nebula which has a rather unique look since it's both an Emission and Reflection nebula, and it has an interesting backstory to boot!
The 'engine' for this nebula is the bright star you see associated with the jagged white "smoke" trail: AE Aurigae. This star puts out about 30,000 times as much light as the Sun making it a member of the most luminous star classifications: O and B. It is also unusually bright compared to other stars in its class.
The Flaming Star Nebula, IC 405
The extreme amount of energy streaming from this star is exciting the gas and dust that it happens to be traveling through (more on that in the next pic) causing the loose hydrogen here to emit a red glow and reflecting off the white dust in front of it giving the impression of 'smoke' coming from the star, hence the name "Flaming Star".
The Journey of AE Aurigae
The star is relatively close to us at 1500 light-years (the galaxy itself is 100,000 light-years in diameter) so it's fairly easy to tell if it's sitting still or moving through the galaxy on its own, which it is, and at a fairly high rate of speed too!
In fact, it's moving quickly enough that some of the modern all-sky star position surveys can see its movement across the sky in only 6 months’ time, and after many observations they can trace the path of this star back to its original position all the way over in the Orion Nebula (also 1500 light years away from us) from where it was gravitationally 'ejected' about 2 million years ago along with another star that we've found that's headed the opposite direction.
At first, I thought this was pretty far-fetched but the more I thought about it the more I realized how much gravitational energy something with 17 times the mass of the Sun would actually have if it got close to something, like that other star!
I also found out that this large proper motion through the sky isn't really all that uncommon for these super-bright, heavy stars with approximately 15% of them being on some kind of 'journey' in the Milky Way. The star cluster "The Pleiades" is an example of a whole cluster of 1000 or so super bright, young stars zipping past us in our corner of the galaxy, kinda like teenagers with fast cars in the neighborhood!
Closeup of The Flaming Star Nebula
Having the white 'smoke trail' reflection nebula superimposed on the emission nebula in the background isn't something I've run across anywhere else, not that my survey is by any means 'thorough', but among the stuff we amateurs take pics of, this one is unique.
I love the dark shadowy folds, little dark details, and all the loopy wispy stuff to the left side of the nebula.
When I shot the Flaming Star the first time I didn't even know all that wispy stuff across the top was even up there! So when I shot it this time I made sure I got it framed right.
Happy Thanksgiving!
Technical Details:
This image was shot in monochrome with a QHY600M camera.
It was shot thru various filters in 5 layers: Red, Green, Blue, Luminance, and Hydrogen / Oxygen-III
Telescope was an AstroTech 152EDT refractor (6-inch) with the entire focuser assembly replaced with a Moonlike 2.5” Crayford focuser with their matching focus motor.
Exposure times
Red: 1 hr, 30 min
Green: 1 hr, 6 min:
Blue: 1 hr, 21 min
Luminance: 1 hr
Ha/O-III: 2 hrs, 44 min
Total Integration Time: 7 hours, 41 minutes
My best attempt out of several tries at Messier 81.
How to Observe a Meteor Shower
Update: November 2021: The Observatory saw “first light” on November 14th, 2021 when I took a nice shot of the Elephant Trunk Nebula (IC 1396). Over the following month gradually I got all the various systems working remotely and was able to do the first remote imaging session a few days before Christmas.
I made a series of videos about the whole process which you can see on my channel on YouTube or watch them on my video page here on the site.
The Holy Grail of photographic astronomy is to have a permanent observatory with everything all set up, perfectly aligned, and telescope, mount, and camera all more or less ready to go at the flip of a few switches. Such things are relatively expensive but not incredibly so, so when an opportunity arose to do this, I jumped at the chance. Some nights it takes me more than 3 hours to assemble the telescope, cameras, guide scope, dew heaters, put it all on the mount and get the mount aligned to the sky, achieve focus, get auto-guiding working and everything all talking nicely to the master computer.
Well, that's three hours I'd rather spend shooting images so wouldn’t it be nice to have a permanent installation somewhere? You bet!
The Plan
There are a number of vendors out there that have dome-style products that you can buy and assemble on site. There are plans circulating around the internet and companies that will build or ship you parts for a roll-off roof designed observatory as well. Which to choose?
I was familiar with the roll-off roof designs from my days at the Cincinnati Astronomical Society where four of the five observatories they had were that style.
I knew domes from my days at the Cincinnati Observatory Center and have to say that for observational astronomy, domes leave a lot to be desired in that you can't really see much sky at all through the dome slit and you don't truly get that "I'm out beneath the stars" feeling that is so cool. You also miss any meteors that may streak by!
With the roll-off roof design, your scope is much more exposed to the elements of dew (which can be amazingly heavy here in South Carolina) and wind. It doesn't take more than a slight gust of wind to smear an image to the point of unusability so this is a big consideration.
Ultimately I decided to get a dome. The roll-off roof observatories are fairly permanent structures and since I was putting this on land I don't actually own, you never know what is going to happen in the future and theoretically, the domes can be disassembled and relocated.
It’s Automatic!
Dome shutter open/close motor
Another thing about the domes is that there already exists software that will coordinate the operation of the dome with the movements of the telescope and mount inside. There’s a motor that turns the dome and another to open and close the dome shutter so the control software has to know where the telescope is pointing and then maneuver the dome opening so the telescope has a clear view of the sky, and then keep it there throughout the session as the telescope tracks across the sky during the hours’ long exposure run.
The fact that this technology exists (it’s even free!) opens up the possibility that you could run the entire observatory from a remote location which seems appealing, maybe as a “next-level” stage of development. It’s actually done quite a bit, it’s just that the people doing it know a lot more than I do!
Concrete Idea
Another thing I know almost nothing about is concrete, which my last contact with was in the early 90s when I mixed up two and a half bags of Quickrete to put up my old C-Band satellite dish.
You can’t just plop one of these domes down on the dirt; it needs to be secure to the ground so it won’t blow away in a hurricane and it needs to be level. Seems like a ten foot square reinforced concrete pad would do nicely! So now I have to find somebody who knows their way around concrete and isn’t going to cost me a fortune. Angie’s List was useless but I have a couple feelers out.
Pier Review
The telescope mount usually sits on a super-solid vertical column referred to as “the pier” instead of the tripod legs you use for portable situations. These things are sunk into bedrock on large installations (like the ones you see in their own permanent buildings) but in my situation I’m going to have to bolt it to the concrete. This means either drilling holes in cement (after its cured) or making some kind of template/form with the bolts in it upside down and in their proper positions sunk into the wet concrete so once dry, the pier can be dropped on top of it with the bolts sticking up through the mounting holes. Then you screw the nuts down and you should be pretty solid.
The other advantage to the pier vs. tripod is that you don’t have to worry as much about the telescope or camera running into the tripod legs which gives you a little more flexibility as you track objects across the sky.
We Need More Power captain!
The observatory site is fairly remote–no electricity or running water so since there are no water-powered telescopes I better come up with some power. As it turns out the people who are into RV traveling have this problem covered with a range of high-capacity, rechargeable batteries with solar panels to keep them charged. 2000 watt-hours seems to be a good amount.
I’ll need to figure out how to mount the solar panels in a good configuration for the Sun and be sturdy in severe weather.
Show me the Data
The last prong to this whole thing is getting the picture data from the telescope. This actually is the most difficult part. As it turns out there is no good way to move that much data over the cellular data services in a reasonable amount of time; you could connect to it and control the observatory just fine this way but retrieving 150 gigabytes of picture data would take a very long time. So I’m looking into cellular modems and how they work to see what kind of responsiveness I can expect from the shooting computer on the scope.
Tight Scope
So while I’m getting all this together I’m working on the scope configuration. The scope that will mostly reside in the observatory will be my RASA 11” scope and when you’re running a remote scope cable management becomes a big issue. Every wire has to be in place and be snag-free no matter which way the telescope moves. So I’ve got it set up in my living room with a stack of velcro wire ties trying to craft the most compact, efficient wiring scheme possible that’s also undoable when I feel like switching the scope out for galaxy season in the Spring or something.
Big project
This is gonna be a fun project—I’ll be blogging about each of the various stages of the project in separate posts.
Bill the Sky Guy
May 5th, 2021
In the movie “Castaway”, Tom Hanks’ character, once he’s discovered he can spear them with a stick and hold them over a fire to cook them opines, “Ya gotta love crab…”
Well I feel the same way, but about the Crab Nebula! I don’t know why I have such a fascination about this object but I remember really being struck by it as far back as when I was a kid reading my Larousse Encyclopedia of Astronomy. It could be because it so graphically represents what it is, an exploded star; or perhaps because it’s got so much sharp detail but whatever the reason, this one is in my ‘top ten’ for sure.
As I’ve acquired bigger and better telescopes I always go back to the Crab during ‘crab season’ to see what I can see now but am always disappointed. Even in my 18-inch scope there’s just the slightest hint of the major two or three filaments and just is never the super interesting thing you know it is.
I’ve been trying to get an astrophoto of the Crab going all the way back to my attempts in the era of film(!) and always came up empty-handed, mostly because I was using equipment that wasn’t capable of succeeding but didn’t know it at the time.
Well fast-forward 30 years and suddenly I do have the right equipment but have still been unsuccessful in all my previous three attempts in the past few years due to a variety of factors regarding scope type, object size, camera quality, and mount capability. Seems like I always got something in that list wrong.
New Recipe
My best effort to date was in 2018 and while it’s not terrible, it isn’t very good either. The stars are round, the sky is black but the color is a bit weird and there’s a bunch of “hot pixels” on the camera masquerading as stars in the background, but most disappointingly there is only a hint of the fantastic detail you see in this thing in Hubble shots. So my goal this time was to conquer all those hurdles and get the shot I really wanted after all these years.
A crappy Crab
So, in one of those rare instances when all the factors that normally vex you move out of the way and align in your favor, I finally have the shot of the Crab Nebula that I’ve been trying to take my whole life!
Supernova remnant the Crab Nebula, Messier 1, in the constellation of Taurus.
Better Ingredients
So what makes this thing so hard to shoot? Well first of all, it’s actually pretty small in the sky. When you look at astrophotos they’re always cropped to show off the object to its best advantage so unless you actually know the object already they all look about the same size in the photos. For instance, my photo of the North American Nebula from a couple months ago covers an area of sky about the size of a ping-pong ball held at arm’s length. The crab nebula is about the size of the head of a pin held at arm’s length so you’re going to need as much magnification as you can get!
Secondly, a long focal length (highly magnified) telescope reveals any errors in sky tracking much more readily so your mount’s tracking speed needs to be really, really accurate and your polar alignment better be pretty close to perfect.
10-inch Ritchey-Chretien Astrograph; Losmandy G11 mount
Thirdly, your camera needs have lots of pixels, more dots in your photos means more detail and since the part of the image you’re actually going to end up keeping is probably only about 20% of the total camera frame you want as many pixels, as tightly packed together on your camera sensor as possible.
Lastly, you need to get lots of really good data. My previous image was 20 exposures stacked together (likely 30 seconds each, maybe a minute tops); the good new photo is about three and a half hours across four different filters which took me from 7pm to 4am to collect including setup.
Murphy’s revenge
In my previous post here I remarked, “Why is it never easy?” Well tonight it actually was! Polar alignment using the star drift method took 25 minutes instead of an hour and my accuracy numbers were a new record. All the hardware was responding to all the software, there was a perfect guide star to lock onto and the guiding software kept my mount trained on it to within an arc-second or so instead of the usual 1.8 so almost twice as accurate. The night was perfectly clear and pretty chilly so the camera’s cooling circuits got the detector temperature down to -25°C; take that you stray noisy electrons!
And finally, the “meridian flip” worked perfectly as well although I still don’t trust things enough to let the software do it on its own. A meridian flip is when you have been shooting an object in the east and it starts to cross the Meridian–the imaginary line in the sky from the North Star to the South dividing the sky into the east half and the west half. Well at some point past the Meridian your telescope is going to get so low on the mount it’s going to crash into the legs of the tripod so you have to stop, rotate the telescope 180° to the other side (now the east side pointing west) and now you’re good for the rest of the night. Well this maneuver has always been fraught with disaster for me with the scope going the wrong way, wires getting tangled, having a hard time reacquiring the target (which is now upside down in your camera frame) but tonight it just all worked and I was shooting again in 10 minutes.
The practical upside of all this is that out of a run of 50 exposures with a certain filter I only had to throw away four instead of the usual fifteen with this scope/mount setup.
What is this thing called Crab?
What is it about this object that gives it its unique look? It’s a supernova remnant, and a pretty recent one at that. It’s also fairly close at 6200 light-years on the next spiral arm out in the Milky Way. I’ve got another image of a supernova remnant, now known as the Veil Nebula which is at the top of my Top Ten list.
The Veil Nebula, supernova remnant in the constellation of Cygnus The Swan.
Even though this is a supernova remnant as well it’s a super old one and sort of indirect. What happened here was that a supernova explosion (now long gone) and the shock wave from it ripped through this part of the galaxy causing all the gasses that were hanging out there to compress and glow.
Supernovas are really big, bright explosions. We can see them literally all the way across the entire universe and indeed, having the Hubble Space Telescope hunt for supernovas in distant galaxies is one of the best ways we have to understand how far away things are and therefore how big the universe actually is!
Harder than chinese astronomy
So imagine you’re a Chinese Astronomer on July 4th, 1054 AD when all of a sudden there’s a brand new star in the sky, a ‘guest star’ as they referred to it. Remember since this is 450 years before the invention of the telescope an astronomer was a guy who just looked at the sky and wrote things down that seemed interesting. Well, this brand new star was four times brighter than Venus, was visible during daytime for 23 days and was seen in the night sky for a year and nine months after. So everything you see in the Crab Nebula Is the actual star itself after a thousand years of explosive expansion. It was also observed by Native Americans in Arizona and New Mexico as shown by petroglyphs we’ve discovered. Pretty much everybody who was alive then saw it because how can you miss a star so bright you can see it during the day?
When a star goes supernova there are basically three possible ultimate outcomes:
The star is completely destroyed
The star leaves behind an earth-sized or smaller ball of pure neutrons. This stuff is so dense a teaspoon of it would weigh millions of tons on the Earth. We call this a Neutron Star. If it’s spinning and giving off radio waves from all the nearby stuff that’s falling onto it, we call it a Pulsar.
If the amount of left-over neutrons in the neutron star exceeds roughly three times the mass of our Sun then it collapses into a Black Hole.
The Crab chose what was behind curtain #2 and has a pulsar with 1.4 times the mass of the Sun compressed into a ball only 20 miles across, rapidly spinning in the center or the Nebula, sending a beam of X-rays our way every 33 milliseconds, marking the original location of the supernova explosion. The nebula itself is expanding fast enough that professional astronomers can actually measure that expansion year by year. The Hubble goes and has a look every now and then each year since it’s been up there which they’ve stitched into a movie! This isn’t the HST version but it does show the expansion over time:
Crabby History
The Crab’s nebulous remnant was first telescopically discovered by John Bevis in 1731. Charles Messier independently found it in 1758, when he was looking for Halley's comet on its first predicted return. Although it turned out not to be a comet Messier included this in his catalog of, ‘things that look like comets but aren’t but I’m writing them down anyway so I’m not fooled again later” which we now call the Messier Catalog and the Crab is the first entry so it’s referred to as “M1”. I’ve heard descriptions about the type of equipment these guys were using back in the 1700s and I’m amazed they could see some of the stuff they saw!
The Crab pretty much existed as a ‘cloudy oval smudge’ kinda thing until around 1844 when a drawing of it by Lord Rosse in Ireland (astrophotography didn’t exist at that time) showed some of the filamentary structure and the way he drew it, it looked like a crab and the name stuck. Other famous astronomers of the day like William Herschel correctly noted that the Crab can’t be resolved into stars but thought as scopes got bigger it would be, apparently mistaking those filaments as not quite resolved stars.
The first real photo was taken in 1892 with a 20-inch scope and that really revealed the gaseous nature of the Crab for the first time. In 1921 they compared the 1892 photo with a much more recent one and discovered the expansion of the nebula. By measuring the expansion over the period of time that allowed them to ‘run the clock backwards’ mathematically and that’s when the connection between the 1054 supernova and the Crab was discovered. In 1949 we were sending radio source detectors up on captured German V2 rockets for some quick peeks above the atmosphere and the Crab was identified as a strong radio source. In 1963 X-rays were found to be coming from the Crab as well. In fact, the X-Ray signal is 100 times brighter than the optical. Five years later the Pulsar was discovered and one year later was also found to be pulsing in sync in the visible light spectrum, a first.
Location Location Location
Here’s a diagram of where the Crab is in our galaxy relative to the Sun.
The distance to the Crab is about 6200 light-years and the object itself has expanded out from a single star to 13 x 11 light-years over 970 years since the explosion.
Crab Out
Well that’s probably more than you wanted to know but suffice it to say I’m crossing this one off of the Astrophoto Bucket List.
Bill
a.k.a. Bill the Sky Guy
Hilton Head, South Carolina
I had the 2000mm Ritchey-Chretien astrograph telescope out in front of my place last week and even though I got an early start it took an amazingly long time to get going that particular night. I have a new small camera that I used to take my Mars pics at Opposition on October 13th but thought it might make for a more sensitive guide camera because the pixels on the camera detector are smaller and the chip is larger than my usual guide cam.
The 2000mm Ritchey-Chretien Astrrograph Scope
Why is it never easy?
And the R-C scope with its long focal length is always demanding that everything be running really well so I thought this would be a way to up my game. As it turns out this new guide camera was constantly losing stars in the guiding software and after taking almost an hour trying to find a setup and setting that would work for it I went back to the old camera which has proven to be solid.
When I’m shooting from the house I can’t see the north star so I have to use the drift-alignment method which is very accurate and takes a long time to get right sometimes. Well, this particular night my rig was real finicky and it took even longer than usual. I started getting things out and ready about sundown which was 5:30 PM and it was now 11:00 and I was barely ready to shoot. I slewed the scope over to my target for the evening, the galaxy M77 in Cetus.
There was near a full moon in the sky that night (97% illuminated or one day past full) and to my dismay even with a 60-second exposure I couldn’t even tell if my target was in the frame, even though the software assured me it was. Crap!
Well by now I was getting tired and if I was going to get anything serious shot that would take at least until 5 AM so I decided to just get as good a shot of the moon as I could and call it a night; just something to make the evening not a total bust. Also, I haven’t tried the new monochrome camera on this scope yet; all the shooting I’ve been doing in October/November has been with the 4-inch refractor for big widefield targets like the North American Nebula (two posts earlier than this one) in this blog. So I was interested in seeing how much sky I could see with this high magnification setup.
Pixels & Moonbeams
So I found the moon and tried to figure out the exposure which because the camera is so sensitive and the moon so bright I ended up taking 30 exposures at, get this: .005 seconds! Needless to say I was done pretty quickly and put the scope away. I didn’t even shoot in color, just straight black and white frames.
I got around to going through the images yesterday and found that 20 of the 30 just didn’t really measure up for one reason or another. I was really surprised that some of the photos were motion blurred; I was figuring at .005 seconds that would be short enough to ‘freeze’ anything!
So had ten pretty good ones and did some stacks of 3, 5, and all 10 to see if there was any difference, none that I could tell. So I did the usual processing maneuvers which in this case was to make the dark areas of the moon a little darker to create better contrast when zooming in and I also ran some sharpening filters to eke out every possible detail.
Well the monochrome camera is just freaking fantastic in it’s detail and the photo I got shows details on the moon I’ve only glimpsed through my telescope visually, even with the 18-inch. So here is a moon pic that is one day past full, 97% illuminated.
Click on this image to open in a lightbox style window to see all the juicy details in this image.
Ok so this is a pretty good image of the Moon. What now? Well you know, sometimes you spend so much time making the image it’s easy to forget to really look at what you’ve got and I can’t think of a better place to do that than the Moon. It is only 245,000 miles away, has no atmosphere so everything is crystal clear on the surface and there’s all kinds of interesting things going on so I decided to really zoom in and take a good look around.
I prepared some closeups of my favorite places since it’s hard to zoom in on images in a web browser although you can right-click on an image tell it to “open image in a new window” and then use Command/Ctrl + or – to zoom in and out.
The bright and obvious crater Tycho, with ‘ejecta’ debris that spreads for over a thousand miles!
Crater Tycho is my favorite crater! This is a testament to what a geek I am; how many people have a favorite lunar crater? Located in the most heavily cratered part of the southern hemisphere it stands as a testament to a really big fast-moving something that walloped the moon back in the early days of the solar system during what is aptly called the “period of heavy bombardment”. Indeed! There are so many impacts in this area of the moon that the craters are overlapping in places.
Here’s a real closeup and you can see that this crater was made by an object that came streaking in from about 4 o’clock and hit the moon obliquely. We can tell this because the central peak is off center and the crater walls on the following edge (10 o’clock) are less well defined.
Hitting Eject
One of the things I like best about Tycho but is not unique to it are the prominent rays of ‘ejecta’ that emanate outwards in all directions. This is lunar soil and rock that got so hot during the impact it turned white as it was being sprayed all over the moon. You can trace these rays out over a thousand miles in some places.
Ejecta from craters on the moon is commonplace for the larger impacts as we will see. In fact they are scientifically useful since if you park your spacecraft on one of the ejecta rays, you can sample the crater itself without having to actually go down in there, which is probably more dangerous than you would want to attempt.
Copernicus
After Tycho, the crater Copernicus is one of the most readily identified because it’s huge and sort of off by itself at mid latitudes in the west-central portion of the moon.
Copernicus Crater and the Apennine mountains curving in from the upper right corner.
There are lots of ejecta coming from this crater but they look a little more random and don’t go out as far suggesting that the object hitting the moon here was larger and slower than the one that made Tycho crater.
The Apennine Mountains in the upper right are a very interesting area of the moon to observe with a telescope when the moon is half lit because the day/night dividing line goes right through here and all kinds of interesting things happen with the long shadows from the low sun angle. I remember one time where half of the mountains were in darkness except the tips of the peaks which were still being lit looking like these super bright points in the “dark side” of the moon.
The brilliant white crater at top left is crater “Aristarchus” and through a scope draws your eye as probably the whitest thing on the moon.
Moonar History
In order to understand what you see in the next photo you need to know how the moon formed in the first place. Early in the solar system’s history the Earth was really just a round blob of molten lava, rock and was starting to cool down into something more cohesive. At that time it’s theorized that something about the size of Mars slammed into us and gouged out a bunch of material that made it out past the Roche Limit where it was too far away to fall back. In a relatively short period of time all this stuff condensed into the moon which conveniently is just about the same size as the Pacific Ocean, which could be the biggest ‘impact crater’ on Earth.
So if the Earth was molten at the time then so would have been the Moon but as it cooled it wasn’t exempt from the general bombardment taking place throughout the solar system and was repeatedly struck in its semi-molten state.
The Southwest portion of the Moon.
I love this part of the lunar terrain because it tells a story. In the center of the image you see a lot of craters where all you really see is the rim but the crater bowl is filled in. Well, these must have been made pretty early when the moon was still fairly sloppy because the crater bowls got filled in with the lava that was still pretty much sloshing around. There’s probably dozens of these in this area. Also notice that the really well-formed, deep craters are much smaller indicating that they are younger due to not being filled in and since all the really big stuff had hit what it was going to hit by now.
You can see some of the ejecta rays from Tycho coming up on the right side of the photo and that’s the brilliant white Byrgius crater (had to look that one up) in the upper left.
Sea In Crisis
The large dark areas of the moon are referred to as “Seas” or in Latin, “Mares” because they looked smooth to the eye, as if watery. We know now that the moon is a very dusty place with the dust made up of what could essentially be thought of as powdered glass; very abrasive and will present a challenge to people and machinery if we ever go live there.
The ‘Seas’ are large expanses of lava that cooled relatively late in the early history of the moon. How do we know? Not so many craters on average as the lighter areas of the moon meaning that the period of heavy bombardment was winding down at that point. You see a crater with a bunch of craters inside it? Old crater.
The Sea of Crises in the NE quadrant of the Moon
This is an interesting one because it’s obviously an old crater, but it’s huge enough to get the designation of “sea” which must give it a terrible identity crisis. Perhaps that’s why it’s the ‘Sea of Crises’…' Or not…
I love the little changes in elevation on the smooth parts leaving a hint of shadow where parts of it have subsided. You can see this kinda thing easily with any decent telescope at around 100x magnification.
Calm Seas
If you back off and look to the left from the Sea of Crises you encounter two more famous moon seas, the Sea of Serenity and the Sea of Tranquility.
The two dark areas in the center of this photo are the Sea of Serenity (top) and the Sea of Tranquility (bottom)
Obviously a newer surface due to the relatively few craters and would have a much higher chance of having a smooth place to land if you should decide to go there, which we did in 1960 and managed to make it happen on July 20th, 1969.
So I have this rockin’ moon image now which is great, but what are you gonna get out of it besides posting it? I thought, “you know, it might be fun to try and track down and mark the locations of all the Apollo missions and read about why those spots were chosen and why in that order”; my inner geek showing through there.
Map On
I have a great Moon app on my phone called MoonGlobe HD (highly recommended) and using it I was able to track down all 6 moon landing sites. I was amazed at how clear my photo turned out and I started wondering how accurately my plot of the landing sites was going to be so I made a rough calculation and it seems that 1 pixel of my moon photo is equal to 1.34 miles on the moon! Pretty cool.
The red box encompasses the area where all the Apollo missions landed. Notice how they completely avoided the rough southern hemisphere although as their methods and successes advanced they did start landing in some fairly adventurous places because the missions were more and more about geology science and less about “hey, look what we can do.”
So here’s my photo with all of the Apollo landing sites marked.
All six Apollo landing sites. That’s crater Copernicus on the middle left. Click for a larger image.
Apollo 11
We all remember the phrase “Tranquility Base here, the Eagle has landed” and the reason it was called Tranquility Base because the Sea of Tranquility was selected as the first landing site out of an original list of 30.
Although NASA would never characterize it this way Apollo 11 was pretty much all about, “Can we pull this off without killing them!” which is understandable since nobody had ever set foot on another world before and quite a bit of the lunar part of the mission was going to be done for the first time ever with no actual rehearsal, just the benefit of careful planning and a calculated reasonable margin of error. There was also, “Oh leave some reflectors and seismographs behind and get a couple suitcases of a variety of rocks…”
The criteria for the landing site were, smooth landing site, no more than 2° slope in the approach path, no mountains and boulders nearby in case targeting was off and mountains might fool the landing radar, minimum fuel consumption, and be reachable with an overall mission on what’s known as a “free return trajectory”.
A free return trajectory is a safety measure that NASA employed in case something went wrong with the spacecraft on the way to the moon after leaving Earth’s orbit. Basically they worked it out so that they would arrive at the Moon slightly ahead of it (to the left) at exactly the right altitude and speed that, if needed, the spacecraft would just sling around the Moon once and head straight back to where Earth was going to be in 3 or 4 days so even if the spacecraft was in poor shape they could at least be at Earth to make a reentry. One of the reasons Apollo 13 was such a dicey mission was that it was not on a free return trajectory.
Apollo 12
The landing criteria for Apollo 12 were pretty much the same as Apollo 11 but NASA wanted to see if they could up their game on navigation and conduct a truly precise pinpoint landing at a specific, preplanned spot as opposed to Apollo 11 which was pretty much, “Anywhere that looks good Neil!”.
So they decided to try and land within walking distance to Surveyor 3 which was part of a fleet of reconnaissance missions to try and get super close pics of potential landing sites.
The mission was almost over in the first minute when the launch vehicle (which was mostly 6 million pounds of liquid hydrogen and liquid oxygen) was struck by lightning twice in the first minute of flight! The engines continued firing however and after reaching orbit a thorough checkout of all systems showed no damage so the mission proceeded.
Apollo 12 had an upgraded flight navigation computer (the landing computer on Apollo 11 was in an almost constant state of overload close to landing) and was used to update 12’s position and get them on track for the precision touchdown which happened ‘by the numbers’ landing less than 200 yards from Surveyor.
In addition to deploying more sophisticated lunar surface instruments, an S-band comm antenna, and a core sample along with the usual rocks, they went over to Surveyor and found some pieces they could take off and bring back with them since engineers on Earth were curious to see how various metals did when exposed to the harsh space environment for and extended period of time. They also brought back some wiring conduit which they knew left the Earth with some organic compounds inside and they wanted to see if any of those had survived three years in space.
Apollo 13
See the movie! Fantastic story and pretty much everything you see in that movie is the way it happened.
Apollo 14
This was essentially the ‘do-over’ from Apollo 13 taking place after a precision landing less than 31 yards from target at the Fra Mauro Formation that was located in the debris field from the huge, relatively recent impact that formed the Imbrium Basin (the big dark area north of Copernicus).
The mission went very will and they got a good variety of geological material (rocks) to bring back for study.
Alan Shepard takes a mulligan on the Moon
At the end of the mission, Alan Shepard became the only person to play golf on another world by hitting two golf balls in lunar gravity using a six-iron head he had had modified to mate to the lunar sample pickup stick tool (you could change out tools on the end). The spacesuit was so bulky that he could only swing with one hand and he duffed the first shot but hit the second one clean and said that even though it was probably a 35 yard shot on Earth, it went about 200 yards on the Moon. So there are two golf balls on the moon. Alan never told anyone the brand of those golf balls either.
Apollo 15
The landing site chosen for Apollo 15 was on the eastern margin of the Imbrium Basin in the region known as Palus Putredinis. There were two main objectives for this landing site. First, the rim of the Imbrium Basin could be sampled along the Appenine Mountains. It was expected that this would provide material from deeper in the lunar crust than was sampled in the Fra Mauro Formation by Apollo 14. Second, this site provided an opportunity to explore Hadley Rille, a photogenic channel in the mare surface that was probably formed by volcanic processes.
Apollo 15 was the first of the so-called J missions, which considerably expanded the capabilities for doing science on and near the Moon. For the first time, three 7-hour-long EVAs would be performed, and a lunar rover would significantly extend the distance a crew could travel over the lunar surface. In addition, the restriction on landing near the equator was lifted. Finally, a sophisticated suite of science experiments was also carried in the service module and used to map the Moon from orbit.
Apollo 16
The Apollo 16 landing site was selected to obtain samples of two highland geologic units, the Descartes Formation and the Cayley Formation, which are widespread on the lunar nearside. Prior to the mission, it was thought that both were of volcanic origin, but the returned samples demonstrated that this is incorrect. Three of the first four Apollo Moon landings were in mare regions and the fourth was in ejecta from the Imbrium impact. When selecting the Apollo 16 landing site, the highest priority was given to landing at a site in the lunar highlands, which occupy more than five times the surface area occupied by ‘Mare’ units.
The Descartes site was certified as safe for landing on the basis of Apollo 14 orbital photography. The specific landing site was selected between two fresh, young impact craters, North Ray Crater (1000 meters in diameter) and South Ray Crater (680 meters in diameter). These craters provided natural drill holes through the regolith at the site, exposing samples of the underlying bedrock in ejecta fragments for sampling by the Apollo 16 crew.
Apollo 17-Final Mission
Because Apollo 17 was the last lunar landing of the program, all of the high-priority candidate landing sites were given consideration again. However, many were eliminated from consideration for either scientific or operational reasons. A landing near the central peaks of Copernicus crater had long been considered, but was now regarded as of lower priority, both because some Apollo 12 samples may have provided an age for this impact event and because three landings had already occurred in the vicinity of Mare Imbrium. A landing in the southern highlands near Tycho crater was rejected because of concerns about rough terrain and mission safety.
A landing on the lunar farside in Tsiolkovsky crater was considered, but rejected because of operational difficulties and the added expense of providing the communications satellites that would be necessary to maintain radio contact between the landing site and ground controllers. A highland site southwest of Mare Crisium was considered, but was rejected because this region of the Moon was easily accessible to spacecraft launched by the Soviet Union. In fact, the Luna 20 spacecraft landed in this region in February 1972, just a week after the Apollo 17 site selection was made, and returned 30 grams of samples to Earth for analysis.
Old Highland Material
The first priority was obtaining samples of old highlands material (older than the Imbrium impact) from as large a distance as possible from the Imbrium basin. All three of the final candidate sites were between 800 and 1000 kilometers from the Imbrium basin.
Young Volcanic Material
The second objective was investigating the possible existence of young (less than 3 billion year old) volcanic activity. This was considered important both for understanding the thermal evolution of the Moon and also because interpretations of orbital photography suggested that young volcanism might have been explosive in nature and hence associated with a high abundance of volatile materials such as water.
Orbital Science
There were two competing objectives for obtaining orbital science coverage on the Apollo 17 mission. First, there was a desire to have orbital ground tracks that had minimal overlap with those of Apollo 15 and 16, so that the maximum amount of new information could be obtained. On the other hand, because Apollo 17 carried several new instruments, overlapping ground tracks with earlier missions would allow data from the new and old instruments to be compared over common areas.
So There You Have It
Well I managed to get hours of entertainment out of a single moon image. Hope you enjoyed it and did a little exploring on your own!
Bill the Sky Guy
December 6th, 2020
In the last couple of weeks we’ve had a handful of clear nights (finally) and while I had the wide-field camera/scope setup at home I thought I would try to see how well it would do on a smaller target like a large planetary nebula; M27 is one of the largest so I gave it a shot.
Finally!!! Back to some "Deep Sky" imaging.
I shot the North American Nebula (NGC 7000 in the constellation of Cygnus the Swan) back in 2017 during one of my first summer trips to the mountains near Asheville NC. I hadn't figured out how to really nail my polar alignment or get my mount to guide properly at that point so instead of shooting 60 2-minute exposures as I would do now…
My latest YouTube video (October, 2020) about getting together the right equipment in the right order to take the best possible photos of Mars, Jupiter, and Saturn with the gear I have.
MotoFocus
I’ve had motors attached to the focusers of my photographic scopes for about a year now and it’s been a tremendous learning experience as well as a boon to well, being focused!
There were a whole bunch of things that made themselves apparent that I hadn’t known to consider until they happened to me, so I thought I would share my experience with the astrophotography community so people would have a good ‘heads up’ if they were considering going this route.
As we are entering what feels like “Phase Two” of the Covid19 virus in 2020 I find myself with more time on my hands than ever since were are still not really open as usual around here. All my stargazes are cancelled until next year at the earliest, and we have had maybe two or three clear nights at most in the last three months so there’s been very little astrophoto activity possible.
I’ve been doing a lot of research and development along a few new areas so when/if we get some clear skies as we head into Autumn/Winter I’ll have some new game ready to go.
First, I’ve made the jump to monochrome imaging in conjunction with a filter wheel for it’s enhanced resolution. I didn’t really want to but my color camera has become so unreliable that it’s just unusable and I’m finding it’s really tough to get service on these things, even when you buy from a major dealer. Monochrome is the next step forward anyway so if you’re going to spend money you might as well keep making progress. When I get the color camera fixed I’ll be able to put up two complete imaging rigs and image the same object in both color and monochrome which should lead to some spectacular pics I’m hoping.
Monochrome presents some challenges: you get color images from a black and white camera by shooting the same object through a series of colored filters and then combine them all as a color image in the computer while processing. The filters are arranged in a wheel that’s controlled by the shooting computer so it can automatically switch the filters when required which is terrific but there’s no guarantee that focus is going to be exactly the same from filter to filter so you need to test and experiment to discover if you’ve got an issue in these areas. I’ve got six filters installed in my seven position filter wheel and one of the filters needs to be 70 focus steps further in than all the others. It took two hours of repeated autofocus runs to find that out.
The new QHY600 camera is really wide field and extremely detailed. I’m expecting to make some progress with it but ya gotta have an entire clear night to take enough data with 4 filters to get a good shot.
Here’s hoping,
Bill Gwynne
aka Bill the Sky Guy
A blog post about my learning how to photograph planets and some shots of Comet Neowise 2020 F3
This is a lengthy video describing how you can use a tool built into the telescope guiding program PHD2 to get you accurately polar aligned without being able to see the star Polaris.
Here is an unboxing video as part of my move to a two camera system with a B/W camera and filter wheel.
Well it’s been an interesting Spring to say the least! I’ve been figuring out how to take astrophotos from home on my porch even though I can’t align to the north star from there. Fun times and a great way to spend all this downtime I’ve been having since pretty much everything I do that classifies as ‘work’ is cancelled.
I’ve got a bunch of new photos to share and have learned a bunch of new stuff!!
In going through the process of preparing the new RASA (Rowe-Ackerman-Schmidt Astrograph) scope for photographic use, it struck me how much is really involved in getting a scope like this ready to do it’s very best. The best way to describe it is that it’s not really a telescope, it’s a system that involves a telescope!
Each year I take part of my summer vacation (August=great time to get out of South Carolina) and head into the mountains of North Carolina or Tennessee for some “total immersion” astrophotography. In past years I’ve gone to the Asheville NC area which has been great but sometimes frustratingly cloudy, so this year I wanted to see if I could find a place where I could set up once and leave everything in place for the whole week.
Some people at the stargazes I give on the Island have mentioned Roan Mountain TN as a dark place worth considering. After some searching I found a terrific AirBnb listing near Elizabethton in Eastern Tennessee that had a nice flat, grassy area within an extension cord’s reach of the main house. My hosts there were extremely accommodating as to what must have been a little out of the ordinary request (“Mind if I set up two large telescopes on the lawn for a week?”), and after a little back and forth to make sure they knew what was coming everything was cool, so moon phases were checked and dates were booked.
Arrival
I got there the last couple days of August and spent the first afternoon doing a thorough, leisurely setup of both the photographic rig (4-inch refractor on the Losmandy G-11 mount and the 18-inch Obsession Dobsonian scope) which I planned to do visual observing with during the camera’s long exposure runs.
Family Portrait: 4” SkyWatcher ‘Triplet” Refractor (foreground) and 18" Obsession in the back
The house I was staying at ended up being a little closer to things than I was hoping but in reality the only part of the sky with significant light pollution was to the Northwest and it was pretty easy to avoid shooting in that direction if you planned things right.
Where’s My Target
I had a list of planned shots I wanted to take this trip. The 4-inch refractor is best suited to taking wide-field images of large nebulas since the camera sees nearly four degrees of sky which is about the width of your knuckles at arm’s length. Last year I had purchased a great photography filter from OPT Telescopes in Riverside CA called the “Triad” because it had three light passbands for light common with space nebulas and this was going to be a good week to use it.
About a month earlier I had sent the mount head back to Losmandy for an upgrade to spring-loaded worm gears (don’t ask) which was supposed to make automatic guiding of the mount work better. I had only been able to test it one time before leaving for the trip and as far as I could tell things were working fine but that was only one night and I was settling in for a week and was a little anxious to see if things would be good for the long-term.
As it turned out things were working very well and I was able to get guiding accuracy to about half an arc-second (very tight!) which allowed me to try longer exposure lengths for the pics. So instead of taking 240 15-second shots I was now taking 60 2-minute exposures which is a very big help when it comes to the ratio of actual image to the camera’s digital noise.
Set Me Up
So for the first night I had to get the mount as perfectly polar aligned as possible (essential for good auto-guiding) and get the telescope perfectly in focus which can take a lot longer than you might think.
Then you have to slew the telescope to your target, see what the thing you’re shooting looks like in the camera frame which might require you to turn the camera a little so that large galaxy is diagonal in the shot instead of being chopped off on the short dimension. This can take a long time too since some of this stuff is so faint you can’t see it at all unless you take a one minute preview image with the gain on the camera cranked up to max.
Ready, Shoot! Wait…
So I was planning on taking about 100 90-second exposures per object so that’s about 1.75 hours of shooting but after those 100 have been shot you still need to take what’s known as “dark frames” which are exposures taken with the lens cap over the telescope. These are used later in preprocessing as a record of the camera’s ‘self-noise’ for an exposure of that length and at that temperature and are mathematically subracted out of each individual image before aligning and combining all 100 images into a single image with an aggregate exposure time of 1.75 hours.
So the whole process of taking one astrophoto was going to take about two and a half hours. So that pretty much limits you to about two images per night under the stars. So you program the computer to take the 100 “light’ and 10 ‘dark’ frames in a row and after that all you really need to do is just check in every once in awhile to see if the guiding has gone crazy or something.
I spent that time at the eyepiece of the 18” Obsession getting some really good looks at old favorites and starting in on my latest observing project: the Caldwell Catalog.
Gotta have your priorities
The end of August is a little late to try and shoot the good nebula stuff in Sagittarius because by this time of year it’s already at or past the meridian (due south) and is setting in the West with each passing minute. So for my first night I went first for the Omega Nebula (M17) which I figured would be fairly bright and easy and for the second image I decided to go for the nebulous areas around Gamma Cygnii, the center star of Cygnus the Swan which was also setting but was so high in the sky it was a good choice as target number two.
I called it quits about 5AM satisfied that things had seemed to go very well and I was looking forward to processing the images the following day.
The Proof
After sleeping to about noon I got some coffee going and started in on the images to see if there was some kind of systemic flaw in my process or not. I was really happy to find out that I was taking some of the best shots I had ever taken. Here’s the Omega Nebula:
The Omega Nebula (54 one-minute exposures)
The nebulosity surrounding star Gamma Cygnii (45 two-minute exposures)
Well needless to say I was pretty excited to see these things coming together as I was working on them. It can take 2-3 hours of processing and editing to get one of these images looking right. For example here is the raw combined image of the above shot before significant processing:
Gamma Cygnii image before processing
As you can see image processing techniques in the computer are just as important as getting good exposures in getting an image you can be proud of.
Take Two
After the previous day’s great weather and good results I was anxious to grab a couple more of these big fluffy things in the sky. For my first target of the night I chose something I had never looked at visually before, mostly because it’s so big in the sky you can’t get it all in the field of view of a telescope, and it’s faint to boot.
So I slewed the scope to the north into the constellation of Cepheus (the house) and IC 1396, the “Elephant Trunk” nebula.
IC 1396, the Elephant Trunk Nebula; this was 1.5 hours of exposure.
I was really happy with the depth of this image and the sharp detail on the edges of the various dark nebula littered throughout this huge cloud of hydrogen. The “elephant trunk’ is that snaky dark nebula on the middle left.
Lifting the Veil–again!
If you were to have been following my astrophotography efforts over the last few years (thanks Mom!) you’d be aware of my fascination with the Veil Nebula in Cygnus. In 2017 I got a shot of it with my older camera which could only see about a third of it. Then in the spring of this year I made another attempt and because it’s so faint I only got two thirds of it–DOH!. So this trip I was bound and determined to find out if I could actually get it all in the frame, and if so get a really good, deep shot. As it turns out I can and I did!
All 3 major areas of the Veil Nebula NGC 6960, 6962/6992 & 6995. This is a 45 minute exposure.
I love the wispy filamentary nature of this one and the two-toned nature of the gas that shows up in photos from this supernova remnant. Here’s my attempt at a close-up from 2018:
Overtime
I had a little bit of time left that night so I thought I’d try and sneak in something easy: a star cluster. These things are generally fairly nearby and therefore bright and you don’t need nearly as much exposure time as you do with a wispy nebula so I swung the telescope over to the constellation Perseus and shot one of my stargaze favorites: the Double Cluster which as you might guess is two open clusters right next to each other in space.
I wanted this shot to more or less match the look you get in the telescope and since this thing is nestled in the arms of the Milky Way I had to resist the urge to super process this one because all the background stars will overrun the cluster members.
The Double Cluster in Perseus (NGC 869 and 884). I always tell people to look for the red star in between the clusters
Three images that night! it was awesome!
What now?
Things had been going so well with everything (gear, weather) that I had exhausted my list of “must-haves” and was now on to the list of “if there’s time”.
Perseus was really well-placed in the sky and I had heard about this interesting looking nebula that was called the Heart Nebula (because it looks kinda like a valentine heart) and right next to it was another nebula they call the Soul Nebula; Heart and Soul, get it??
I couldn’t get both of them in the shot (the Heart itself took up the entire camera frame) so I decided I would make this my first attempt at a mosaic astrophoto. It took a lot of extra effort in processing to get them properly oriented and you had to process the two images identically or they weren’t going to match and you’d see the line in the sky where the image boundaries were. This image could still use a little work in that regard but if I can get it straightened out this might be my first large format print.
The Heart and Soul Nebulas IC 1805 and IC 1848. This is a 1.5 hour exposure for each object.
This particular image really drove home the point how valuable it is to use ‘adjustment layers’ in Photoshop, which is where I finish off the appearance of all of my images.
Snack Time
By this time I was wondering where all the clouds were? I’d had 4 clear nights in a row and over the 6 day shooting period I was only to lose 1/2 a night to clouds; what a perfect little window of weather at exactly the right time.
By now I had more or less exhausted the list I’d made up in advance and was actively scrolling, trolling around on the iPad app looking for a good ‘subject’ and I stumbled across something I saw visually decades ago but it now presented itself as a cool photographic target: NGC 281 the “PacMan Nebula”. When it comes to the entertaining names these things have, this is one of the best. This thing is not all that easy to see visually but with this 1.5 hour exposure, it pops out pretty well against the background sky. The PacMan Nebula is about 10,000 light years away in the outer Perseus Arm of the Milky Way, and munches his way through the constellation of Cassiopeia.
NGC 281 the “PacMan Nebula” in Cassiopeia
Going Deeper
By day five of this excursion I was both ecstatic and feeling a little beat! When you stay up to five am every night for a week it eventually catches up with you and I was almost hoping for a cloudy night! I’d lug all my stuff down to the observing area at dusk each night and by the fifth day it almost felt like I was ‘reporting for work’!
So I decided to finish off the night with a ‘challenge’ shot: The Perseus Galaxy Cluster. I’f you’ve read some of the other blog posts here you might have seen the shot I took of Markarian’s Chain, at the heart of the Virgo Galaxy Cluster. When I got done processing that image I compared it to the map and was flabbergasted that there were over 200 galaxies in that shot, one of them being 6.2 billion light years away! That exposure was only a half hour so I thought that since things were going so well I’d try a more difficult version of the same kind of shot.
It didn’t take long to get the scope pointed since it was right in the same area of the sky as PacMan but the problem was it was almost impossible to see these galaxies with my preview image even with the camera gain jacked up to full, so I had the mount control software do a “plate solve” which is making an assumption of what you’re looking at. take a picture and then compare it to a map of the sky to verify that yes, you are pointed where it says you’re pointed. There was no way to frame the object(s) in the camera since you can’t see it but since it’s wide field I figured I could sort it all out later in editing.
So I set up a two hour exposure sequence, verified that things were running well and went back upstairs to take a nap! Here’s the photo, which turned out to be both amazing and disappointing in certain ways.
NGC 1275 *Perseus A” and the Perseus Cluster of galaxies. Two hour exposure.
Ok so this image is amazing in that it’s deep (long aggregate exposure), crisp and there are a hundred galaxies at least in there most of which are at a distance of 250 million light years which is 5 times farther away than Markarian’s Chain in the Virgo Cluster.
At the same time it’s a little disappointing in that the galaxies don’t really stand out against the busy field of background stars which are right in the plane of the Milky Way and since the cluster is so far away they don’t appear all that much bigger than the stars. I found it very difficult to get the galaxies to ‘puff up’ but not affect the stars too much when processing this image. Nevertheless, they’re in there. If you click on the image so it opens in a ‘lightbox’ look horizontally across the middle for a string of ‘stars that look fuzzier than the stars around them’; those are the galaxies. I can easily count fifty but if you compared this image to the map (below) I bet you could get up to 150 at least.
Map of the Perseus Cluster of galaxies. Perseus A is at the left center of my image as one of the easiest to see in the shot.
So it ends up being being impressive intellectually, if not visually.
NGC 1275 (the dominant cluster member) is also referred to as Perseus A since it’s a strong radio source in the sky but try as I might, I couldn’t pick up any Steely Dan!
Globular Cluster M22
I really like the fact that with the 4-inch refractor and the big sensor in the camera I can se almost four degrees of sky. That makes it possible to show some objects in a larger context which can be interesting and creative.
Most of the globulars are not in the plane of the Milky Way but rather above or below it, but some are, and M22 is one of these–just off the top left of the ‘teapot’ in Sagittarius. It’s a spectacular cluster when you really get up on top of it with 200x or so–it’s amazing. Since it’s in a dense star field looking pretty much right toward the galaxy’s center I though it would be great if I could get shot of this jewel in it’s own little corner of space, just hanging out in a pretty starfield.
Globular Star Cluster M22 holding down the fort in Sagittarius. Definitely click on this one for a larger version.
Astrophotography is Humbling
So if you’ve read this far you may think this was a flawless week; well not exactly. There was one image that even though it was late in the week and things had been going very well, just inexplicably wasn’t right. Some kind of weird thing happened with guiding and it was all over the map and by the time I threw away all the bad images out of 45 taken I could only use 15, and that was stretching it.
So here’s an image where just about nothing went right: NGC 7023, the Iris Nebula.
NGC 7023, The Iris Nebula-a not very good photo…
“So what’s so terrible about it?” you might be thinking. Well look at it larger by clicking on it. See how the stars look like eggs? You kinda get that at the edge of images but this was right in the center! The short exposure time reduces the signal to noise ratio so that when you process enough to see the detail in the nebula, you get this grainy fuzz in the outskirts. There’s no crisp edges to the nebula boundaries which is probably due to the fact that guiding was not really very accurate at all and since these are two-minute exposures it was wandering all over the place.
I’m really discovering that for the cloudy stuff you need 1.5 to 2 hours to get enough light from the object to work with and still be able to maintain a nice dark sky background.
The Obsession
My plan to observe visually through the Obsession 18-inch scope while the camera was snapping away was dampened (quite literally) by some of the thickest dew I’ve ever had to deal with while observing.
The 18-inch Obsession on the observing field.
Even the dew heater I installed in the secondary mirror couldn’t keep up and it was so heavy on the scope that it seeped down inside the digital telescope position display box (the “ArgoNavis”) and gave me this bizarre error message:
Definitely not what you want to see. So as it was explained to me by my AirBnb hosts, “Mountain Dew is not just the name of a highly caffeinated soft drink!” I ended up having little towels and washcloths draped over the eyepieces, the front of the scope (when I wasn’t using it), the ArgoNavis…
Once I knew what I was up against I was able to get some observing done, but I was surprised at how “not quite as automatic as you might think” the picture taking was. I did however end up adding a dozen objects on the ‘done’ category of my Caldwell Catalog observing project.
Here’s a Gallery of some of the other kind of photos you take on vacation.
Really happy to have had a great trip with fantastic weather, gear that worked and some of my best efforts so far in doing astrophotography!
I don’t know if my AirBnB Hosts Warren & Sam actually want more astronomers showing up to take over their lawn but because they were so gracious and contributed to a fantastic week for me I’m going to give them a plug. Their AirBnB listing can be found here. It’s a great place even if you’re not going to ‘scope out’! I even have video of Sam and I playing a trombone and bagpipes duet on Amazing Grace!
Carpe Noctem!
Bill the Sky Guy