back to M20

Once the moon passes through the prime part of my sky, I can start shooting a few more subs...Here is another 30 minutes of exposure added to the previous picture of M20 below. Still a bit grainy, but notice how detail is starting to come out, especially the fainter nebulosity around the bright stuff.

In my never ending battle with equipment, I'm currently facing problems with wear in the reduction gears of the R.A. drive motor, and can only use 15-20% of the shots I shoot. That means this 30 minutes of exposure took nearly four hours to shoot. If there is any advantage to this, it's that when and if I get myself into a premium mount and drive, I will know enough to be able to take full advantage of it. In the meantime, I am just waiting for the inspired idea to hit me that will eliminate the current problem.

At least the color problems appear to be somewhat banished; there is no color correction or balancing in this shot at all-just stack the subs, stretch the dynamic range (surprisingly little) and increase color saturation; what you see is what the camera saw. Compare this to the last picture I took with the 300D.

Because it is so easy for me to only see what is still not up to standard, I thought I would include the first picture I ever took of the Triffid Nebula, before I started all the rebuilding of my rig.  This is AFTER stacking all the shots I was able to get, and after applying all the PhotoShop tricks I have learned...the original pics were even worse.

What surprises me is that these are all done with the same telescope. So many advertisements make is seem that if you spend 3 or 4 grand on their spiffiest stuff, you'll be shooting pictures like this-if nothing else, this year has shown me just how hard astrophotography is. Of course, truly good equipment costs many times that much, but those manufacturers are not trying to sell to unknowing magazine readers, and they make no claims that anyone can just do it by pushing a button.

(Don't forget that ALL of these pictures are clickable for a larger version)

M17, the Call-It-Anything-You-Want Nebula

M17 is usually called the Omega Nebula, except by people who call it the Swan Nebula. Or the Horseshoe Nebula. Or the Lobster Nebula, or the Checkmark Nebula. The names reflect a tendency our eye has to add pattern where we want to see it, even if there isn't any there. Early sketches of this object can look like any of the above names, and almost never look much like photos. Herschel gave it the name Omega in the early 19th century, so that is most commonly used now. I think Charles Messier came up with the best name for it-17.

Starting from M8 and scanning north with binoculars, this will be the third or fourth obvious patch of cloudy brightness you would find, depending on the size of your binoculars. It lies north of the Triffid, and just below the Eagle Nebula. There is a bright open cluster of a few dozen very young and hot stars in the center, which in turn are heating up the hydrogen gas in the area, which in turn emits the reddish light. The blueish bits are dust, which just reflects the natural starlight.

The main section of the nebula is roughly 15 light years across, and has a total mass of about 800 times as much as our sun. That sounds heavy, but that is still spread over a huge area...except in the very densest knots of gas and dust, that is still close to being a total vacuum.

Toward the right of the picture is another emission region; in this part of the sky, as you increase the size of the telescope and the length of the exposure, more and more stuff keeps appearing. If you are able to see the Milky Way from your location, this is all spread along the very bright patch around and above the Teapot. I keep saying it, but this is the perfect time of year to just point some cheap binoculars that direction-the night sky is anything but just a bunch of blackness, and you don't need a scope to enjoy it.

Po-ta-toes, Precious

Okay, excuses, but not apologies. I am leaving at 6 in the morning for Orange County, the Fun and Excitement Capitol of Southern California, and I wanted to get one last picture posted before leaving. So the stars are all shaped like taters; who cares about a little tracking error when you're in a hurry. At least it shows how much effort is required when I take pictures with ROUND stars.

This is M16, the Eagle Nebula-squint your eyes hard enough, and you might see an eagle's wings in flight, in a sort of "highly stylized, like a coin designer" manner. Or you might see the same shape as Eagle Rock near Los Angeles, which also requires that you lower your expectation of eagleness somewhat. So what-it's a very cool nebula, because it is the source of what is likely the most famous Hubble photos ever taken; ones that pretty much everyone is familiar with; the ones called the "Pillars of Creation".

Yeah, I know; this image is not nearly as inspiring. Hey, I did this in just a couple of hours, without ANY TAX DOLLARS at all. Let's see the Hubble boys make the same claim.

Next week I expect to shoot some better quality pics of this and nearby M17 as well. Stay tuned...

A better M8

This is a bit closer to the natural color balance as seen right in the camera. It is made from roughly 70 minutes of exposure, culled from over 5 hours shot over the last two nights. The full size master is really showing a lot of dimension that is not visible at the 1200px size here (click on image to enlarge it) but I can't post 12 megabyte pictures too often...so we'll live with this. It's not bad, at least in my own biased view.

By the way, this is not cropped-this is the full frame of the 40D, nearly 1.5 degrees across. That is nearly three times the size of a full moon. I know I go on and on and on about those binoculars, but really; try it.

SN2011dh

Never mind the grainy picture-loads of lights, including the chihuahua beacon aimed as ever at my scope. This picture is meant to show the relative brightness of our old friend supernova 2011dh. In this post, it was clearly brighter that nearby mag. 13.85 USNO J1330149+471027 (to the left of the supernova; it is a faint star of unknown distance within our own galaxy), and it held that brightness for a few weeks. That plateau of brightness is what defines this as a Type IIp supernova-p for plateau-nothing too fancy there. Now, it is declining, and is probably no more than mag. 14.5 or so. Within 6-12 months, it should be well below the reach of a scope the size of mine.

More improvements in processing...

This is the same image from the two recent posts. Every time I get to where I think I'm nailing a certain step, I learn some more...one teeny tine little check box suddenly cured some real trouble I've been having with color. This image was simply stretched for dynamic range, then the saturation increased. That's it.

Now, I am EXTREMELY anxious to get M31 into a dark sky and collect some serious photonage.

I have also realized that when sets shot on different nights are combined, DSS is averaging the reference frames for each, rather than applying each night's reference to that night's subs. That is why there is such an uneven background in the latest shot. Once I find those settings, this shot could end up improving even more.

Triffid redux

I think I am making some real progress here. This is one of my old favorites, the home of the Triffids...known to less geeky people as Messier Object number 20. If this fails to impress, look back a few posts...it was one of the last things my trusty 300D ever photographed, and is now one of the first for the 40D. This one looks a little more like the pictures the Big Boys take. There simply is no comparison. It's not all down to the new camera; I am still learning the ways of Digital Sky Stacker as well.

I am sure I have mentioned it before; one of the lovely things about this nebula is the presence of all three types of gaseous nebula-the red areas are dust and gas that have been heated by new stars within, enough so that the gas is now emitting light of its own. The bluish areas are reflection nebulae-they are not themselves producing any light, just reflecting that from local stars. The dark lanes are dense clouds of dust, and oddly enough often house the brightest and hottest stars of all-just hidden from us in visual wavelengths.

Astrophotography Expedition to Utah

A couple of weeks ago, I was working in Mesquite, Arizona, so we hauled my scope out for some dark skies and high elevation in southern Utah. Of course, it was a full moon, and the scope was never taken from the case. This is a 30 second exposure, with the camera resting on the hood of my truck. At midnight.

This photo shows two things-one, moonlight is just sunlight-leave the shutter open a bit, and you can't tell it from daylight, except that if you look hard, you will see that the sky has stars in it. Two, it shows just how hard it can be to get good images of deep sky objects when there are other sources of light around.

M31, another hour

New camera or not, there is a hard limit on what can be captured in a bright sky. This time of year, M31 is still to the northeast in the sky, and that region is full of city lights here. This shot adds about an hour to the previous one-note that noise is greatly reduced, but nothing fainter is showing up. To really capture this, I'll need to wait another month or two for it to be in a darker region of my local sky. This is still only the central region; the disk extends well past the cluster at the bottom of the picture.

As it is, just to differentiate just part of the galactic disk from the background sky, I had to stretch this image to the point that any meaningful color was destroyed. Here is what it looked like after stacking, but before stretching the dynamic range-the sky itself is just as bright as the galaxy. Once again, my thanks go out to Target and Home Depot, for choosing lights that shine up as well as down, and lighting up half of the valley at 3 in the morning. Remember them when your utility company tells you to use less electricity. (And let's not forget chihuahua lovers, who still believe that I can train coyotes to eat their stupid pets, and therefore aim floodlights at my house to ward them off, like some sort of electric garlic. As I have said, if I could train coyotes, they wouldn't have any chihuahuas left at all.)

This was, by the way, my first shooting session where the camera was controlled remotely from my computer, while I sat indoors getting a head start on the processing. Since I often sit outside minding the scope  in order to avoid hearing the stuff my family likes to watch on TV, I'm not sure I will use that feature a lot...

M31

Only 20 minutes, and very hasty...but what a difference from the shot a few posts earlier. That;s M32 bottom center, a globular cluster orbiting M31.

This image is uncropped, and was not magnified...M31 is a big sucker, many times larger in the sky than the Moon is. It will take at least three shots mosaiced together to show the entire galaxy.

Canon 40D and Messier 8, together at last

Okay, I was not exactly prepared for how much better this camera would be...

This is only 12 minutes of exposure, and less than 5 minutes of Photoshop post-processing. I don't even know how to operate the camera in the dark yet, and it is already putting all my past pictures to shame. I don't have a shutter release cable for it yet, so all these subs had to be shot by hand-and since none of the reference frames I have on file apply to this camera, I had to shoot all 60 of those manually as well. Hence, only 12 minutes left for gathering photons.

Gear Replacement

Well, the 300D won't be missed for long...I got a 40D on eBay today. Assuming I'm not going to be totally ripped off, that solves the camera conundrum quite nicely. And also, thanks go out to my sister and her famdamily for a "laser" collimator, soon to be delivered via Amazon. Both of these items are big steps up the quality ladder- am proud of what I've been accomplishing with the stuff I have, but in some areas I think I am ready for a step up.

Pics to follow soon!

Right on time-another setback

Well, in the last six months, I've had a mount that was irreparable damaged, which somehow was restored to life. Then my scope was squished, and miraculously was revived. This weekend, after removing the battery from my camera, the power sorted in the flash capacitors somehow shorted to the motherboard, causing-quite literally-a small explosion. It is now an ex-camera. It is not resting. it is not pining for the fjords. It has met its maker; it has, in a word, snuffed it. Photography is, for the moment, off the menu.

However, it is still July, and I have a nice telescope-and eyes! The views available to the direct south this month are spectacular, even with nothing but your eyes and some darkness. A small pair of binoculars will easily bring 20 to 30 of the Messier objects into plain view, some of them dramatically so. So while I figure out what to do about a camera, there is still much to do, and as I have mentioned before, photography has often distracted me from enjoying the spectacle that looking through a scope can provide.

If you only have some binoculars, here is what I recommend that you try. Late this evening, look south and find Antares-it will be the brightest star to the south, and is clearly reddish. In binocs, it is striking-almost uncomfortably bright to look at. About half of one field of view to its upper right is another star, and forming a shallow "V" between them is a globular cluster, M4. Let your eyes adapt to the dark a bit, then see if you can see a fuzzy cotton ball to the right of Antares. At first, you may see it best if you look slightly to one side of it-the very center of our vision is not very sensitive to light, actually. Looking just to the side while paying attention to the target is called "averted vision" and is a learned skill for visual telescopists.

To the left of Antares, see if you can find a group of stars (not a full constellation, but an "asterism") that looks like a teapot. Find a trapezoid shape, a bit leftish of the bright band of the Milky Way if you are lucky enough to see that, and in Saggitarius if you happen to know where that is. There is another star above the trapezoid that forms the top of the teapot, with the spout to the right. Once you see it, it will forever be obvious.

To the lower right, where this picture says M7, there is a bright star with a smaller one to the right and lower-the sting in Scorpius' tail. Above it and to the left is M7 itself, a wonderful binocular view of an open cluster that was even described by Ptolemy 2000 years ago. M6, to its upper right, is the Butterfly Cluster, dominated by one red supergiant star and a few blue supergiants. These things don't show their splendor in photos, so they get passed by a lot (by me as well-I've written about open clusters before in this blog.) But with binoculars or even a very small scope, they are dazzling.

Above the teapot's spout, almost like steam, are a couple of the most magnificent nebulae in the sky. M8 is easily visible with the eye alone in a dark area (I can even see it from MY yard, after 20 minutes of dark-adaptation.) Just above it is a "w" of stars, around which the Triffid Nebula M20 is located. There is another cluster around the upper left of the W too.

Once you find M8 in binocs, try moving directly to the left about two fields of view and see if you can find another cotton ball-this is the globular cluster M22. If you scan around the area between and above M8 and M22, there is almost no limit to what binoculars will show, and be sure to notice the background to it all-the utterly uncountable number of stars fading as far back as your eye can see.

This is definitely the best month of the year to watch the sky, especially if you don't have a load of fancy gear. And the area to the south is so full of beautiful sights that you need not be able to read 9or even own) star charts to find the good stuff. My binocs were only about $25, and they offer splendid views; this hobby definitely does NOT require a large budget. Get outside tonight and look up!

M20 the Triffid Nebula

The name "triffid" refers to the three lobes of this nebula, not to the home planet of the Triffids. Pity, in my opinion.

This is another early shot, only 20 minutes and with a near-full moon close by. In 2-3 weeks I should be able to get some much nicer subs. The star field in this area is just as fascinating as the nebulae there; M20 (and M8, which is even more spectacular) are located in the dark band that runs through the middle of the Milky Way. Scan around due south with some binoculars around midnight and you'll likely end up finding this without much trouble.

This nebula is a major star birth region, and like the Orion Nebula, has all three types of nebulosity present-the red is light emitted by gases heated by stars within, the blue is simply reflected light from stars inside dust and gas clouds, and the black is clouds of dust. Once I get some more light collected, the blue will be much more evident.

If you can't beat 'em...

Now that the Summer Milky Way is coming into the slice of my sky that isn't as blown out by light pollution as the rest of the sky, here comes the Moon again. May as well take a shot of it. Here we have 50 exposures, averaged with Registax.

M31, the Great Andromeda Galaxy

M31 is probably the largest deep-sky object in our skies, over three times as large as the full moon. It is also our closest neighbor, and is fairly similar to our own Milky Way galaxy. It's still early in the year for this one; I just happened to be up an hour before dawn and managed to grab about 10 minutes worth of photons, and it's not a spectacular image. The disc of the galaxy is easily seen in most photographs to encompass the large globular cluster at the bottom of this picture (M32.) This is an uncropped photo; I would need to make a mosaic of at least three shots to include the entire galaxy. The bright core here is easy to find with binoculars in even a polluted sky, and can be seen by eye alone by many people in dark skies. However, the rest of the disk is relatively faint. In this shot, the main dust lane closest to the core is pretty obvious; less so is the larger band of dark dust further out, simply because I didn't get enough starlight for it to stand out. The color balance is a horrorshow as well. Ultimately, using large numbers of short exposures is not in any way a substitute for long exposures, and when there are only a few shots to stack, the flaws in the technique are pretty obvious. I'm uploading this shot merely as a baseline; I have never tried shooting it before, so this is what I have to build on once it's within range a little earlier in the night, during August and September.

M4 Globular Cluster

A break was needed from the supernova; for the last few nights there has been a wicked fog bank rolling in like a locomotive around 10 or 11, but I managed to grab this before it hit last night.

Pity how this fared in converting to jpeg; I'll try png later and see if I can't bring back some dynamic depth.

More M51 & SN2011dh

Taken June 14th. Roughly two hours exposure time. All the really interesting stuff seems to happen when there is a full moon...

A few more facts about the New Star

Here are some randomly assorted tidbits about SN2011dh and other supernovae.

First, the simple...in 1572, astronomer Tycho Brahe noticed a new star where there had been none. This was just before the age of the telescope in astronomy, and Brahe was one of the first scientists to collect careful data about what he saw. He published a book about this (and many other things) called De nova stella (On the new star) the next year. "Nova" is Latin for "new". In time, astronomers came to call "new stars" novas, or novae. In reality, novae are not new stars at all, they are stars that have become brighter, but that would not be known for a while yet.

In the 20th century, astronomers began to finally understand how impossible big the universe is. When novae were observed in other galaxies, it was obvious they must be pretty bloody big explosions. The term supernova was coined in the 1920s to describe those. 

There are two types of supernova. Type I involves stars about the size of our own, which for various reasons blow off their outer layers. Our star runs by converting hydrogen into helium, using the vast heat created by its own gravity. Once the hydrogen runs out, it will fuse the helium into other stuff like carbon, and then sort of shrink into a white lump of hot stuff called a white dwarf. That will be the end of the road for our own Sun. But if a white dwarf has a close companion star, and if they are close enough together, it can collect matter from that star. Once enough stuff is collected, it explodes; that is a Type I supernova, and it usually leaves the original star not too badly damaged. Binary stars can do this repeatedly, and many planetary nebulae are the gases blown off by Type I explosions, still lit from within by the parent star or stars.

But really big stars can keep fusing elements into heavier and heavier stuff, until the core is finally made up of iron. Unfortunately for the star, fusing iron doesn't release any extra energy, and the core collapses under the incredible force of its own gravity, and at nearly 1/4th the speed of light. Once it collapses so far that the nuclei in its atoms are touching, it can't go any further, and the collapse is stopped so rapidly that a shock wave bounces back out, blowing away the remaining part of the star. THAT is a Type II supernova. If the original star was less than 20 times the mass of our sun, it will leave behind a Neutron Star, such as the one that I "discovered" earlier this year. If it' over 20 solar masses, a black hole will result.
 
Supernovas used to be observed only every century or so, but with the sheer number of amateur astronomers today, there are a few hundred per year seen throughout the visible universe. They are still very rare-out of the scores of billions of stars in our galaxy, supernovae only occur once every 50 years or so. Supernovae are given names made up of the year they were observed, followed by a letter A-Z. After the first 26, they start with aa, then ab, etc. This would therefore be the 112th supernova detected in 2011, although it is certainly one of the most visible.

Even though Type I and Type II events are so totally different, to the eye they appear very similar. Only when instruments were invented that could detect the presence of certain elements was it learned that there were two types. A spectrograph can show what elements are present at a light source. A Type I explosion shows no hydrogen, since the parent star has already used up its hydrogen. The kind of star that is big enough to implode can do so before the hydrogen runs out, so it does show hydrogen spectra. The names Type I & II were well established before it was understood just how unrelated the two things really are. Words have a way of sticking around unbidden at times.

With an estimated peak brightness of around 1 billion solar luminosities, if SN2011dh had occurred 30,000 light years away it would appear to us to be as bright as our sun.30,000 light years is a terrible long distance...our entire galaxy is perhaps 100,000 light years across. If such a supernova happened within 3,000 light years, it could be pretty bad for us, since the radiation from the blast would remove all of the ozone from our atmosphere. That is bad for our DNA, since ozone blocks much of the dangerous stuff from our own sun. There is some evidence that the Ordovician Extinction nearly half a billion years ago was caused by a nearby supernova.

There are no stars within that distance today that are candidates for such an event, so the job of wiping out all the life on our planet is left in our capable hands.

All of the elements heavier than iron are formed in the explosions of this type of supernova. If you are wearing any gold jewelry, that gold was created in the few moments after the collapse of the core in a supermassive star. By heavier, I mean having a greater atomic weight-go Google "periodic table" and have a look.

SN2011dh hit its peak brightness within a week or so, and will fade over the next year until we can't see it in amateur scopes any longer.  After a couple more weeks, it is expected to fade to a plateau for several months, then continue fading. that plateau will still be easy to photograph with scopes like mine, however.

As a last unrelated thought-if they are correct about the progenitor of SN2011dh being around 25 solar masses, then it formed a black hole in the first moment of the event. However, contrary to the popular notion, it will not "suck up" everything in its area. For a simple thought experiment, imagine that our star were to become a black hole (it can't, but just play along.) Assuming it had the same mass as it did when it was just our sun, the Earth would not be affected at all-it would still be orbiting something with the mass of one sun. Our year would remain unchanged; the moon would still orbit us at the same rate, etc. Of course, it would get very, VERY cold.

ba-BOOM!!!!

Oh, it's been a long couple of months...broken computers, new computers, software that won't run on new computers, etc. etc. etc. Once all of that was sorted out, it's time for June Gloom and overcast skies all night. Thankfully, last night stayed clear enough to get two hours of subs of M51. Sure, it seems like I shoot M51 a lot...why again? Because on May 31, the first images were taken of a supernova in M51. here is a link to an article about it, and some info on one interesting fact about it-it's not uncommon for supernovas in other galaxies to be discovered by amateurs, but this one also had its debut via Twitter. I don't know if that means anything or not. Certainly, it doesn't concern the start that exploded-it happened over 25,000,000 years ago; the light just reached us this month.

The upper photo is from May 2, the lower from June 12. Compared to the photos in the article I linked above, the supernova is even brighter-compare it to the star to its left (USNO J1330149+471027, which is in our own galaxy, and is a lot closer.) In the raw data from my camera, the supernova is brighter than the core of the galaxy itself, and may still be getting brighter. That happens not because the explosion itself takes weeks or days-it doesn't-but because as the fireball grows, there is more surface radiating light. At the Keck Observatory, they have measured parts of the fireball expanding at 11,000 miles per second.  The most up-to-date news articles I have found are about a week old, and it was still clearly around 14th magnitude, slightly fainter than the star next to (which is mag 13.85.) The star that blew up was about 20 times the mass of our Sun, making this a Type II Supernova, which is what happens when really big stars run out of fuel and collapse. It has been designated SN 2011dh. Once the fireball diffuses, the remnant will be a planetary nebula, although sadly we will never see it from this distance.

M51 is actually two galaxies; the upper object is another galaxy that is passing near or through the other. The interaction caused gases and dust that had been spread thinly to condense, all along the arms of M51, and there is furious star birth going on there, lighting the dust up with blue light (a lot like what is going on far closer to home in Orion.) When these sort of star nurseries are formed, they tend to create hugely massive stars with very short lives relative to our star. In the "before" picture, notice how that band of gas has many blue knots of dense star formation; based on the supernova's location and size, this star was likely not more than 100 million years old. (I have heard that a candidate star has been identified in an older Hubble picture, but I don't know any details of that yet.) That's a fast and furious life by stellar standards-our Sun will live ten billion years before dying, and it's actually brighter than all but 15% of the stars in our galaxy; most stars probably live even longer.

I was initially worried that the nearly-full moon plus the chihuahua lights in all their glory would kill any chance of seeing this, but there is obviously no problem there; this thing is bright. Plus, since I was not trying to make the galaxy appear as bright as possible, I didn't have to "stretch" the contrast much in post processing, and that makes for a very tidy photo; a handy lesson for me as I keep learning to grab better raw images. While stretching is one way to make dim objects visible, longer exposures are another, and this clearly shows the increase in quality that would result from being able to keep the camera open longer. (This picture is a stack of 30-second exposures; as always, the quality of the clockworks in my drive is still a limiting factor.)

Pretty cool for the first supernova I have ever seen!