Last night I was at a star party in very rural Arizona where it is very dark. I didn’t have a lot of time for photography, but I had to get the Zodiacal Light after sunset.
That nice vertical pillar of white is the Zodiacal Light. The Zodiacal Light is caused by sunlight reflecting off of dust in the plane of our solar system. Since this dust is in the plane of our solar system, it shows up along the ecliptic (or Zodiac). The ecliptic is almost vertical with respect to the horizon at sunset for people in the northern hemisphere at this time of year so the light really stands out.
But there are some other interesting things in this image. The Pleaides stand out near the top and above the pole on the right you can see the faint smudge that is the Andromeda Galaxy. In the middle of the image about 2/3 of the way up is a small streak. I checked for satellites in the area and there now no bright passes (or Iridium flares) so this is probably a meteor. At the bottom you can see a curved line. That is clearly a jet (I sat it naked eye as well) probably training at the Yuma Proving Grounds.
I was just going to post this on flickr (which I did) and wasn’t planning on a blog entry until I did a little closer inspection and started realizing all the other stuff that I captured.
The comets from last fall have been fading, but they are not gone. Last week, two of them had a fairly close encounter in the morning sky. On February 6th, Comets Lovejoy and Linear (X1) were just two degrees apart. Unfortunately, cloudy mornings ruled in Tucson for a while before and after that.
I finally got my break Sunday morning. Looking outside at 4:30am, it was clear so I grabbed my camera and headed to my dark site. The comets were fainter, but easily visible in my pics.
Comet Lovejoy is the upper blue blob and LINEAR is the blue fuzzy patch near the bottom center of the screen. At the very left of the frame is the open cluster NGC6633. I used my Canon 60D with 75-300mm zoom lens at 300mm, f/5.6, 120sec exposure at ISO5000 on an iOptron Skytracker. In other words, my usual setup.
These comets are still visible but moving farther apart. Universe today has a nice article on how to find them if you want to check them out.
I like taking unusual pictures sometimes. They aren’t always the most spectacular shots, but they show off unusual conjunctions that may happen fairly often but are rarely photographed.
Tonight’s shot that falls into that category is the Moon and Uranus. I didn’t think I was going to get a chance at this on as it was raining in the early part of the evening. By chance I happened to be outside around 9pm and it had cleared so I grabbed the camera and went for it. The following shot was taken with my Canon60D, EF 75-300mm lens at 220mm and f/5.6, 0.5 second exposure at ISO3200. I fired up Stellarium to verify which of the fainter objects was Uranus and put a little line pointing to it (and it took forever since my computer with Lightroom and Photoshop had a hard drive crash and I am currently waiting for replacement parts I had to use alternate photo processing programs…don’t worry…a good backup exists!)
In October, we will have a totally eclipsed Moon very close to the planet Uranus. I look forward to capturing this pair at that time, clouds willing!
I have been busy and not had as much time to do any astrophotography recently. Fortunately, I had some good luck and timing yesterday.
Wednesday morning, I woke up to news of a supernova in M82. Fortunately, I saw this before I went to work. I was scheduled to work with some students at Tohono O’odham Commuity College in Sells last night and thought I might get a chance to try to catch the supernova from there. The college site is nice and dark so it was worth a shot throwing my equipment in the car. Fortune also smiled with clear skies when I got out there.
I was using my Canon 60D, EF 75-300mm zoom lens and iOptron Skytracker, my usual setup. Although there are people with larger, better setups out there that will no doubt take more spectacular pics, I can at least purse the record for the person who imaged the supernova with the smallest setup!
I took some pics of M82 and the nearby galaxy M81 a few weeks ago before the supernova. Here is one of those pics. I took this one on Christmas Eve and believe I used my 250mm lens so the scale is a little different.
Okay, now here is the one from last night. The two lines point to the new little point of light that is the supernova (I did not crop the pics the same and they were taken with slightly different lenses so the scale is different). Click the images for larger versions.
This supernova is interesting for many reasons. First, M82 is undergoing a rapid burst of star formation due to a recent pass by the nearby galaxy M81 (also seen in the pic). Increased rates of star formation lead to higher rates of supernova. Second, M82 is a relatively nearby galaxy (only 12 million light years away or so) which means we can study it in greater detail than more distant supernova.
Finally, this is a type 1a supernova. Type 1a supernova form when a white dwarf star sucks matter off a nearby companion star. White dwarfs have a maximum mass about 1.4 times the mass of our Sun. If you add more matter than that, you get a huge explosion which destroys the star. This white dwarf suffered that fate leading to the supernova we are now observing.
Since type 1a supernova always happen when the mass hits 1.4 times that of our Sun, they are always about the same brightness. If you know the brightness of an object, you can figure out its distance. Type 1a supernova are very bright and can be seen in distant galaxies and are very important for astronomers to determine the distance to other galaxies. The more we can study nearby ones, the better we understand them and the better we can measure the distances to other galaxies. Therefore, astronomers are training lots of scopes on this supernova right now!
Oh, I got so excited about the pics, I should mention that we saw it visually as well. We were using a 6″ Celestron Nexstar SE and could see a little bright spot in the galaxy right where the supernova is. I am always nervous showing objects like this to people as you sometimes get the disappointed “Is that it?” reaction. The students last night, however, were happy to be able to see it and I didn’t have to deal with that common reaction. So I can tell you it is visible with a 6″ or larger scope…wouldn’t surprise me if people spot it with even smaller scopes.
This supernova looks like it was discovered before peak brightness. It will probably get brighter for another week or two before starting to fade. How much brighter is an open question and hard to predict. We don’t know how long it took after the explosion for us to discover the supernova (several pre-discovery images have already turned up) and there may be intervening dust that dims the supernova. Worst case scenario, it will not get worse for a week or two. Best case scenario, it brightens another couple of magnitudes.
My sympathies to the northerners who have to brave the cold to see it…I was out in just a sweatshirt last night!
Just a quick star trails shot I did last night…well, if you can call 43 minutes quick. This is 103 exposures of 25 seconds each put together with StarStax to create this image from Saguaro National Park east in Tucson. I used my Canon 60D and Tokina 11-16mm f/2.8 lens at 11mm and f/2.8. I wanted the saguaros in the foreground. I didn’t center on polaris since the farther west I pointed, the more the lights of Tucson interfered. Hope you like it.
When I was in grade school and first getting into astronomy, the Horsehead Nebula was one of the most intriguing objects in the sky. It was on the top of the list of things I wanted to see. When I got my first little 60mm refracting telescope, I spend hours scanning Orion looking for it, never finding it…and of course never listening to people who told me (correctly) that it was WAY beyond the reach of a 60mm telescope!
Earlier this week, I had the pleasure of going out on a shoot with an excellent astrophotographer, Sean Parker (if you don’t know his stuff, go look now!) He wanted to try out the iOptron Skytracker I had and he had borrowed a Canon 5D Mk III and a 70-200 f/2.8 lens so we had some great equipment to play with.
He took several shots of Orion using different exposures and got the Horsehead! I was thrilled to see this, but since this is a lifelong obsession of mine, I wasn’t quite satisfied. I wanted to get a pic of it with my camera and my lens (even though neither my camera or lens are as good as what he was using). So Christmas Eve, I went out with my Canon 60D and EF-s 55-250mm zoom lens. Since my lens can’t operate at f/2.8, I had to use longer exposure and higher ISO, but am pleased to report that yes, I got everything (although I didn’t take and blend multiple exposures…I have a way to go before I get as good as Sean!)
The Orion Nebula is at the bottom right with the Running Man just to its upper left. In the far upper left of the image is the Flame Nebula. Now look closely in the pinkish haze to the lower right of the Flame and you will see a VERY small dark horsehead shape. I got the nebula! Yes, I nerd out over that.
Although this is the shot I really wanted, I of course took some others as well. I will start off with the Andromeda Galaxy.Next I will go for the Pleiades. Notice the gas around it. We used to think (and some astronomers still mistakenly will say) that this is the cloud of gas and dust in which these young stars were born. However, the IRAS (Infrared Astronomy Satellite) mission showed that the stars were plowing through this gas at a high rate of speed. IRAS showed the shockwaves as the stars interact with the gas. Given the very different velocities of the stars and gas, this is almost certainly not where they were born.
The constellation of Auriga has a wealth of star clusters as it is in the heart of the winter Milky Way. A wide shot can capture three of them at once. M37 is the bottom of the three, M36 is the middle and M38 is at the top. The Messier objects aren’t really in any particular order around the sky! These are all open clusters. The stars were born at the same time from the same cloud of gas and dust, but they are not gravitationally bound to each other so the stars will scatter around the galaxy as time goes on. They are not quite close enough together to get all three in the field of view of my 8×42 binoculars at one time…I can get either the two and the third will be just outside the field of view!
I will make one more stop here. This pari of galaxies is M81 and M82 about 10 million light years away in Ursa Major. M81 (on the right) is a spiral galaxy much like our own Milky Way. M82 on the left is an irregular galaxy (sometimes nicknamed the Cigar Galaxy) that recently passed nearby M81. The gravitational interaction between the galaxies led to a burst of star formation in M82. M82 is called (appropriately) a starburst galaxy.
Winter in Tucson is a great time to observe. The nights have not been too cold and the skies have been clear. I hope to get out and do some very wide field stuff in the next few days and hope that it is clear this weekend as we have our great ISS passes coming up.
I got behind posting here, but last Sunday morning I went out to get Comet Lovejoy as it was passing a little over 5 degrees from the Hercules Globular cluster, also known as M13. It would have been better Saturday morning, but I got back from a trip late Friday night and getting up early Saturday just didn’t happen.
The problem Sunday morning was the Moon. The Moon was approaching full and lit up the sky when I got to Saguaro National Park east. I couldn’t see Lovejoy with the naked eye, but found it with binoculars. I took a few pics while waiting for the Moon to set. Once the Moon set, there was a very brief window before morning twilight started brightening the sky. Fortunately, I was ready to make the most of the 20 minutes or so I had.
Here is Comet Lovejoy in the lower right of the image and the fuzzy blob of M13 in the upper left.
Next I zoomed in for a closer view of Lovejoy.
Lovejoy still has a very nice tail. I could see the comet as a fuzzy blob naked eye once the Moon set, but it is not quite as bright as it was a couple of weeks ago. Finally, as the sky began to gradually brighten, I found a nice saguaro and did a much wider shot with the comet.
The Moon is entering the morning sky and will make Comet Lovejoy much less impressive, but it should still be in reach of binoculars. The comet if forecast to slowly fade to a magnitude of about 6.0 by the end of the month when the Moon will finally get out of the way. You would need really dark skies to catch it with the naked eye although it should still be all right in binoculars. Due to the Moon, I probably won’t try for it again for a couple of weeks. However, I hope to use some of the slower time around the holidays next week to try some photography in the evening!
I have posted lots of pics of Comet Lovejoy and managed to get up early enough this morning and brave the chilly Tucson (below freezing…don’t judge northerners!) temps to take some shots.
Saguaro National Park east is about a 10 minute drive from where I live. I wanted some pics with some nice foreground objects so I hiked into the park a little bit to get to the first batch of big saguaros. I got several wide shots with a 35mm lens. I used a feature on my Skytracker that will track at only half the rate the stars move across the sky. I did this to split the difference between the land and sky, keeping both of them reasonably in focus with minimal blurring during the 20-30 second exposures I was using.
Of course I felt the need to put on the longer (250mm) zoom lens and try a two minute shot of the comet. The tail is developing nicely and covers several degrees of the sky.
Comet Lovejoy was visible to the naked eye and it is definitely brighter than M13, probably a little brighter than 5th magnitude. Easy and nice binocular target, naked eye under dark skies. For finder chart, Heavens Above is a good place. Just set it to the time you want to observe.
I should note that Lovejoy is moving farther into the northern sky. For much of the continental U.S., it can be seen after sunset and before sunrise, although it is much higher in the sky and easier to see before sunrise. The farther north you are, the easier it is to see after sunset (although Mike Weasner got it after sunset from Oracle, just north of Tucson a few nights ago so anything Tucson or north is fair game for sure!)
I am enjoying this comet, but could the next one please be a good evening object?
I have always wanted to try a star trails picture. A couple of weeks ago, I had an evening at Kitt Peak. The Moon was waxing gibbous and very bright and lit up the domes very nicely. I was with a group over by the 0.9 meter telescope so I set up my camera outside, programmed it to take 30 second exposures for a few hours, and went about my work.
I ended up with
162 262 pictures by the time we were getting ready to go. I made some adjustments in Lightroom to tame the bright sky and then imported them into a free program called StarStax. StarStax will add the individual images automatically and create the star trails picture for you. There are some options you can adjust, but it’s pretty automated. Here is the result.
Overall I am pretty pleased with the first attempt. I can spot a couple of flaws to clean up (and I would like to figure out where they came from, but I might have to look closely at 162 pictures to find the bloody things!) You can see the north star in its tight dance around the celestial pole and many other stars making nice trails. The lights of Tucsonare off to the right.
I have some old pics I used to make time lapses. I might go back and put together a few more of these from those old pics.
Another shot from my night on Kitt Peak a few days ago. This is a wide shot taken from the Visitor’s Center.
You can see the iconic McMath-Pierce Solar Telescope in the background and the sky glow from Tucson on the left. However, if you look on the right side of the image, you will notice a faint green glow and possibly even fainter red if you look close. This is a real phenomena called air glow. Due to air glow, the sky is never completely dark. Airglow occurs all over the sky but is usually more pronounced close to the horizon since you are looking through a thicker layer of atmosphere.
There are several sources of air glow. During the day, atoms in the upper atmosphere are ionized by sunlight. When the ionized atoms and electrons recombine, they give off light…and oxygen can give off green light in the process. Cosmic rays striking the upper atmosphere contribute to air glow as well. Finally, oxygen and nitrogen can react with hydroxyl ions in the upper atmosphere and give off light through a process called chemiluminescence.
Air glow is not visible during the day as it far too faint. Even at night, you need to be in a very dark site to capture it. Thursday night was the first time I have captured this elusive phenomena.
- The Zodiacal Light and Some Other Things
- Two Morning Comets
- The Crescent Moon and Uranus
- Supernova in M82
- Saguaro Star Trails
- Hunting the Horsehead
- Comet Lovejoy and the Hercules Cluster
- Lovejoy Rising
- Star Trails Over Kitt Peak
- Air Glow Over Kitt Peak
- Green Flashes From Chile
- An Open Letter From Comet Lovejoy