The Place To Be On A Saturday Night!

If you find yourself in Tucson on a Friday or Saturday evening with time on your hands and thinking you would like to take in some stars of the celestial type, where else would you want to go than Starizona, the only astronomy-themed store I know that has regular hours at night!  They've cut back a few years ago from 4 nights a week to just weekends, but it is a great place to go to sneak a peak at the moon or planet that might be out.  Located adjacent to one of the busiest streets in Tucson, Oracle road serves as testament you don't need perfect skies to do a little observing.  And while deep sky objects are a little beyond the limit there, the real purpose for the evening hours are for customers.  For those who want some experience with their scope or new camera or new attachment they've purchased, there is no need to go at it alone.  Just set up your equipment in the Starizona parking lot and Dean Koenig or one of his able staff will be glad to take you through the details of setting up the scope, showing you how to use it, and how to tweak the performance of your new gear.  In these pictures Dean, in the dark shirt, is demonstrating the adjustment and using of a Hyperstar attachment, what the red camera is attached to on the front of the telescope.  Most any time photos are being taken there (amazing enough given the cars and skies), a crowd soon follows.  There were a good 4 or 5 telescopes of different types set up, at least 3 of which were being used by new owners.

The ulterior motive for our visit last night was that our friends Dick and Nancy had arranged having a new telescope set up from Lunt Solar Systems, a local manufacturer of solar scopes.  They have partnered with another company to offer stellar telescopes and binoculars in their product line, and Dick, a local optical designer, was interested in a new 6" doublet refractor model. 

If you know Dick, he always has a camera at the ready, and he was out taking flash pictures - at a star party!  Who does that!?  Anyway, in my single use of flash at left, I shot from the hip and got a pic of Dick behind his camera as he took a group shot.  At right, his S.O. Nancy is at left, and Dean Koenig's wife Donna joined Melinda to catch up on news and gossip, illuminated by the gentle lights of the store with the 2 second exposure.

As a result of Dean's customer service, he gets nearly all of my astronomical business, down to the DSLR cameras I use, ordered through him. Even with his vital local status, as a loyal customer, he usually cuts me a discount, as if I need a reason to go anywhere else...  I know my buddies up in Phoenix come the 250 mile round-trip to see him, and just knowing that he is there to help his customers get started, I've never hesitated in sending someone to him when they ask where they should get a telescope.  Normally I tell folks to join the astronomy club to use different scopes to see what they like best, then go to Starizona to see Dean for sales and service and talking shop under the stars.  We should all have a local business like his for our needs!

An Evening of Stars and Rain!

My buddy Pat wanted to see my Celestron 14" plus Hyperstar in action, plus check out a new site near Benson, so we went out last night for a few hours.  Shown at left, the Hyperstar is produced and marketed by Starizona, a local astronomy shop, and allows a Schmidt-Cass telescope like my 14" diameter scope to be used at "prime focus".  The advantage of the design is the short focal length, leading to wide fields and short exposures.  It effectively transforms the scope to a 660mm focal length, F/1.9 telephoto lens!

We had planned to go out last weekend, but as most any amateur astronomer will tell you, it is most always cloudy on the dark-of-the-moon weekend (or if someone bought a new telescope) and that was true last weekend.  This weekend, the forecast was also for clouds, but some predicted a few hours of clear skies early, so we took a chance and hit the road!

We arrived before sunset (always a good thing to NOT be setting up in the dark!), and the scope went up quickly on my more-substantial AP 1200 mount rather than the one shown above.  After allowing the scope to vent its interior for a bit to cool down, I installed the Hyperstar triplet corrector lens, focused on Venus and I was ready to take some twilight flats to help calibrate the frames I'd take when it got dark.  After sighting the mount on Polaris align it to the Earth's rotation axis, it was ready to use.  Since it had been months since I'd used the setup myself, I went to the brightest fuzzy thing in the sky to make setup easy - the Andromeda Galaxy!  Even though I just shot this a couple weeks ago, it was good practice, and a good comparison to the longer exposures needed with the slower 11cm refractor I used for that shot.  Shown here is a stack of 5 exposures of 90 seconds each - yes, 450 seconds total exposure!  Besides the main galaxy Messier 33, composed of perhaps 200 Billion stars are two of its companions, the smaller M33 upper left and M110 lower right.  Of course, the bulk of the individual stars you can see in the picture are in our own galaxy...

As the forecasts had predicted, clouds formed in the SW and slowly moved towards us, so we hustled to get in a couple more galaxy shots (Pat has a thing about capturing distant galaxies!).  From his back yard in Tucson he had often searched for Messier 33, another nearby galaxy to the Milky Way, and not too far in the sky from the above M31.  But alas, he had never spotted it from home and was amazed at it's appearance in binoculars and in his 10" scope.  Shown here is a single (!) 90 second exposure with the Hyperstar.  So it has some noise, but you get the idea of its spiral structure, and some of the brighter stars and clusters in the 2.5 million light years distant galaxy can be spotted.

Just as the clouds reached the zenith, I started a series of exposures on NGC 891, an edge-on galaxy located not far from the above objects, though this one is much further away at 30 million light years.  Clouds allowed 4 exposures of 4 minutes total exposure before closing out the sky.  But even so, the fast optics allowed a reasonable exposure.  This has a very low surface brightness, and views through a telescope are often disappointing, but takes careful scrutiny to spot the spindle shape and even the dark lane in an 8 or 10 inch telescope.  Note that down on the right border of our blog is a photo taken of it with my longer-focus 11" Newtonian telescope many years ago that perhaps shows more detail...

We got socked in right afterwards and about the time we packed up and drove back to Tucson, it actually started raining!  Rain was NOT in the forecast, but given the sparse summer rainy season we had it is great to see coming down.  By the time I got home (about 10pm!) it was coming down at a good clip, and the Weather Service claims we got about the highest totals in town, nearly .1"!  Not much by most standards, but given the fact we caught the above photons AND got to enjoy some rain showers, it was a nice night!

The Cast of Characters!

A week ago I posted the time-lapse of the Omega Centauri globular cluster rising past the 2.1 Meter Telescope of Kitt Peak National Observatory.  I was amazed how well the cluster, as well as a pair of galaxies showed up so well with 15 second exposures, which are what each of the frames was exposed!  While Omega is visible to the naked eye (and spectacular even in binoculars), Centaurus A is strictly barely visible in binocs, and NGC 4945 was unknown to me till glimpsed in an early version of these clips.  The labelled frame from the time-lapse is shown here to jog your memory...

 

The other night (29 April) I went out to photograph the individual cast of characters with my Celestron 14" (C-14).  My friend Marilyn came along for company, since Melinda had to work that night.  We were out near Kitt Peak to leave the sky glow behind us.  Because these objects are very low near the horizon, no light pollution could be tolerated.  The trip was also a test of the new (for me) AP1200 mounting, which I've used for visual use a number of times, but have yet to use for photography.  The C-14 was used with a Hyperstar - a lens system that allows the telescope to be used at prime focus - in this case, a 660mm lens at F/1.9 to keep exposures very short.  I also used a 1.4X tel-extender so I was actually shooting at 925mm focal length, F.2.6.  After finally getting everything aligned, installed and collimated, I started exposing, starting first with Omega Centauri.  While doing so, I also had installed my 70-200 zoom to shoot a wide-field tracked image of the trio using Melinda's camera.  That exposure is shown here with north up.  It is a total of 3 shots, total of 9 minutes exposure.  All 3 non-stellar objects are neatly shown, but it still surprises me they were visible in 15 second exposures!  Granted, that was with a wide, fast (F/1.8) lens...

 

Omega Centauri is beautiful pretty no matter how you observe it.  I was thinking this shot was pretty good, with 630 seconds total exposure, but as I was stacking the 10 exposures, the new Astronomy Picture of the Day featuring Omega came up.  It was shot from South America with the cluster nearly overhead, not 10 degrees off the horizon like it appears here.  So of course, the linked image is even more spectacular, but I still enjoy the one I took with my own setup.  The cluster is about 16,000 light years away from us, much nearer than the galaxies seen in the above wide views.  The description from APOD says there are 10 million stars in the cluster - simply amazing!

 

Next object I imaged was NGC 4945, as it was culminating very near the meridian.  Since it only reaches 9 degrees off the horizon maximum, every little bit helps.  This galaxy is actually pretty close to us as galaxies go, only about 12 million light years away.  At 9th magnitude it is barely seen in binoculars, but would be a lot more observed in the Northern Hemisphere if it rose higher in the sky!  This stack has 9 minutes total exposure.  The Wiki link above describes that this galaxy is in a nearby cluster along with Centaurus A, explaining why they are pretty close in the sky.  It is also quite large, the length is nearly 2/3 the diameter of the moon!  It would be nice to be able to go deeper with more exposure, but likely isn't worth it as low as it is...  The small elliptical at the left edge is NGC 4976, about 3X further away than 4945.

 

Finally it was time for Centaurus A, a most unusual-looking galaxy.  Also known as NGC 5128, its other designation identifies it as a radio source.  It is the 5th brightest galaxy in the sky, just below naked-eye visibility, and looks strange because of its spherical overall shape, but with a dark obscuring lane.  This image is only 5 frames with 6.5 minutes total exposure.

 Overall, it was a fun night and the Ap1200 worked flawlessly.  All the above exposures were taken WITHOUT guiding to assure accurate tracking!  I just let the mount track on the objects, and even with a little breeze, round images almost always resulted.  The only exception were the 2 frames from Centaurus A that I had to discard, otherwise, I included all images exposed!  I got back home right about 1am - a long night, but invigorating since I got to observe with my own equipment, looking at objects on my own list - as opposed to the public observing I've been doing lately.  I figured that this was just about the first time I've been out imaging with my own equipment in over 2 years!  Perhaps some more this weekend!

Hyperstar Snapshots

I've mentioned using the Hyperstar before with my Celestron 14". Click on the "Hyperstar images" label on the right middle to see earlier posts. The lens set replaces the normal secondary of the mirror, allowing the short focus of the telescope primary to reach the camera focal plane directly with the camera on the front of the telescope. It converts the optical system to an equivalent 670mm focal length lens at the astounding F-ratio of 1.9, with nearly a 2 degree field of view! The lens set, developed and built by Starizona here in Tucson, is a marvel of telescope optics. The fast f-ratio permits very short exposures, normally less than a couple minutes at the darkest sites at ISO 800. When shooting bright Messier Objects in the Milky Way, even shorter exposures must be used to keep the image from saturating.


While out observing the weekend of the 4th, just as a demonstration, I shot a number of summertime Messier objects with 45 second exposures on the Canon 20Da. I was shooting automatic darks, so after the exposure, it took a 45 second dark to subtract from the image. During this time, I moved to a new field, restarting as soon as it was ready. No guide stars, just the G-11 mount tracking as normal... So the enclosed 5 exposures were taken in under 10 minutes!

Four of the objects are clouds of mostly hydrogen gas appearing near the brightest part of the summer Milky Way. These clouds of gas are star formation regions and often have star clusters associated with them, where they've formed. The reddish glow is caused by the young hot stars causing the hydrogen to fluoresce, much like the bluish glow of a mercury light. Generally there are dust clouds that show up in dark silhouette against the glowing gas.

From the top is the Triffid Nebula, Messier 20, with star cluster M21 to the upper left. The image to it's right is the Lagoon Nebula, Messier 8. Both of these gas clouds have dark lanes caused by dust. Continuing at left, the next image is M17, the Omega, or Swan Nebula (visualized shapes, if you use your imagination!). The last nebula image is M16, the Eagle Nebula - clicking on the image loads a larger view, allowing the "Pillars of Creation" to be more easily seen. This object was made famous by the Hubble Space Telescope image, showing how dust and gas condensed to form stars and planetary systems. The lowermost image is Messier 11, a galactic star cluster, sometimes called the "Wild Duck Cluster", from a V-shaped wedge of stars visible in a small telescope.

While these snapshots show slight trailing and other faults upon close examination, they show how swiftly an image can be built up in a fast optical system. Normally, I would guide carefully and stack many exposures to bring out the subtleties of a faint object, but sometimes, it is nice to take some nice snapshots of bright objects!

Weekend Observing

Last weekend was the long holiday weekend, and with the monsoon rains still absent, Melinda and I headed out of town to take advantage of some dark sky observing both the day before the 4th and the day after. Moonrise was about midnight, but we were able to enjoy a couple hours of desert darkness each night before heading back to the lights of civilization. I wanted to photograph wide fields of the Milky Way, and Melinda wanted to take some closeup shots through a telescope, so I set her up shooting through the little Meade 80mm refractor. When we went out Monday night, I shot through the 14" plus Hyperstar, and she shot some wide fields. For this post, we'll cover a few of my favorites.


Joining us on the western slopes of Kitt Peak was a long-term visitor from Germany, Christian. We met him a couple months ago at an astronomy club event, and invited him to join us. He is quite the avid visual observer, packing a 16" telescope, so provided us some spectacular views while we took some pretty pictures. Here he was examining Venus in the still-bright twilight.

And while I posted a similar shot of the planetary conjunction in just our last post, here is one taken the night before from our darker observing site.

My favorite object might be the center of our Milky Way galaxy. I can just gaze at it endlessly with my mouth open in amazement. Just the thought that the cloudiness is caused by untold millions of stars, interrupted only by clouds of dust and gas is just amazing to me. It is relatively easy to image too - the wide shot at left is a stack of 9 - 3 minute exposures with a wide-angle 20mm lens. The greenish glow along the bottom is a bit of air glow as the horizon is just out of the frame. The bit of shadow in the lower left corner is the shadow of a tree that was barely in the first couple of frames... Otherwise the field is a mass of deep sky objects that serve as potential future photographic targets.

One of my favorite fields is just above center - the dark nebula referred by some as the "Prancing Horse", or the "Pipe Nebula". Regardless, the mass of dust clouds obscuring more distant star clouds is an amazing field, reaching across 30 degrees of sky to the red super giant Antares and the globular clusters that frame it. This shot is a stack of 8 frames of 20 minutes total exposure with a 50mm lens. Be sure to click on the pictures to load the screen-wide versions.

I'll wrap up this post with a view of southern Scorpius. On a good night from Iowa, the bottom arc of the Scorpion hugged the southern horizon. Because Tucson is 10 degrees of latitude further south, the Scorpion is raised by that same amount, so some of those objects are easier to observe. There is an object called the Cat's Paw Nebula also known by the less-glamorous name of NGC 6302. Shown at left here is another shot with the 50mm lens showing the full arc of the southern part of Scorpius, with the bright stars of the stinger at left. Just to it's upper right is the paw print of the nebula, glowing red because of the florescence of hydrogen gas. On our return trip Monday night, I shot it with the 14" telescope and Hyperstar lens (670mm, F/1.9)with 20 minutes of exposure. While I don't remember ever observing this object visually, Christian tracked it down for us, and we spotted one of the brightest "paw prints" through his 16".

All in all, between the picnicing on the 4th sandwiched between 2 nights of observing and 2 movies over the weekend ("Karate Kid" and "The Secret in their Eyes"), we were plum tuckered out and ready for the workweek to start to get some rest! The dark desert skies were the highlight for me - with the rains coming, it might be months before we get out again...

Another McNaught Trip up Mt Lemmon

Last night (a Saturday), with a bright quarter moon setting about 1am and Melinda at work, I decided to head north of Tucson again to try imaging Comet McNaught (2009R1) again. I got it acceptably well last weekend, but the comet is supposed to be brightening as it approaches the sun, and it might look a little different... Unfortunately, as it approaches the sun, it continues to dive towards the horizon, so will be lower and not available as long as last weekend.


Like last trip, I left home about midnight for the 1 hour drive to San Pedro Vista, 17 miles up the hill and just over 7,000 feet elevation. This trip I used the 14" Celestron with the Hyperstar optics, so it was equivalent to a 700mm lens working at F/1.9. Even working in the dark, it was straightforward to set up, and I was ready to shoot by 2am.


With time to spare, and the Milky Way blazing overhead, I needed some alternate targets. I started out shooting one of my favorite objects to show at dark-sky star parties, Barnard 86, a dark nebula in Sagittarius. While a dark cloud of dust and gas may not sound very spectacular, just being able to spot it against the glowing star clouds of the Milky Way is indeed very neat. B86 is easily spotted just above the spout of the teapot asterism, located between a small star cluster (NGC 6520) and a bright star. It shows up well on images too, though is smaller than imagined after spotting it visually so many times. This image is from 10 stacked 45 second exposures, so about 7 minutes total exposure with the Canon XSi.


I also shot some more frames of the Iris Nebula, but the focus was a little off, so won't embarrass myself here!


Finally, right at 3am the comet was spotted just above Capella (Alpha Auriga) on the northeastern horizon. The sky was a little murkier than last weekend, and the comet, if anything, was less impressive than last week - perhaps because of it's lower altitude. In any case, I shot a few frames of it. Generally, it looked very similar to last weekend, a long blue ion tail and a short stubby dust tail. The comet is almost north of the sun, so generally the ion tail is swinging around slowly to the north. Compare this picture to the post last weekend(link above) - both have north up and west to the right... This image is from a series of 45 second exposures that were then stacked using the comet head as reference, so that the stars appear as trailed. After a dozen frames, morning twilight started, and I began to take down the scope. For dessert, the sky presented me with a glimpse of the Pleiades rising in the brightening eastern sky.


There was some talk of the comet being visible in the northwest after sunset, but I don't believe it will be worth writing home about - small and very low in the sky. So this is likely my last attempt to chase it down...

Old Business

On the last dark-of-the-moon a few weeks ago, I headed west towards Kitt Peak for some astro imaging. It seems like forever since I've had an observing session with the C-14 and digital camera, and with some clear Arizona skies, it was time! In the springtime, multitudes of galaxies rule the sky, so there were a couple groups that easily fit into the C-14 plus Hyperstar combination.

I usually arrive to set up just before sunset so that the telescope can be assembled, allow to cool a bit, then the photographic gear installed and focused before twilight so I can do "twilight flats" to help calibrate out unevenness in illumination. While the sky was fantastically clear, there was a bit of a blustery breeze that came up and irked me into the evening... One of the drawbacks to observing at high elevations, the wind can come out of nowhere, even though it is calm on the desert floor.

First up was the group of galaxies that are gathered around Messier 106 (NGC 4258) in Canes Venatici (Hunting Dogs), not far from the Big Dipper in Ursa Major. I "discovered" the galaxy a few years back when doing the springtime messier Marathon - it has a bright core, but a large extended fainter halo that shows up nicely in an exposure. There is an abundance of galaxies scattered throughout the frame, and the edge-on spiral below right may be a companion (NGC 4217). M106 (number 106 in Charles Messier's catalog) is about 24 million light years away. Of course, all the stars visible in the exposure are much closer to us in our galaxy. The streak of light through the frame is a satellite that moved through the exposure, still lit up by the sun even though dark at my location... The blowup at right actually shows a fainter one as well. This exposure is a cumulation of about 25 minutes of exposure on 9 frames that were added together with the Canon 20Da.


I then moved down to the constellation Leo and shot the "Leo Trio" of galaxies, made up of M65, M66 and NGC 3628 (CW from lower right), all about 35 million light years away. This grouping is a favorite of visual and photographic observers and never disappoints. Unfortunately, in moving south of the zenith, either the angle of the scope changed, or the wind picked up and it was nearly impossible to keep the guide star centered on the cross hair of the guide scope. After the 9 minutes of 3 exposures shown, I gave up - it was just too frustrating. The enlarged images caused by the wind are evident. As a result, even though it was a clear night, it was an early night. I could have done some wide-angle imaging, but it was hours for the Milky Way to rise, and small galaxies don't show up well with just camera lenses. So I was home by midnight and got to see a bit of Craig Ferguson before turning in. A fun night just to get under the stars, but frustrating as well. It isn't always equipment issues or clouds that can mess up your plans!

Astronomical Snapshots With The Hyperstar

While I have fun trying to image the night time sky, the effort of getting a "proper" image that is fully flat fielded, dark subtracted (correcting for electronic noise and non-uniformity in illumination in the telescope), as well as stacking dozens of images to bring up a faint signal, is just plain work! So on my usual partial night of observing, I usually only get one or two such objects. But sometimes I take "snapshots" to see how an object looks in the telescope field of view - then perhaps chase it down another night.

Case in point are these short exposures taken in the last month or two as test objects. The first was taken just this last Friday - I went out to shoot comet Lulin once more, and to work on a few potential objects for the observing list. This pair of galaxies was found from the East Valley Astronomy Club's edge-on galaxy list. The designations are NGC (New General Catalogue) 4631 (upper) and NGC 4656. Thought to be about 25 million light years away, this galaxy pair is sometimes referred to The Whale and The Hockey Stick, from their shapes. This image is cropped down slightly from the full frame of the Celestron C-14 plus Hyperstar imaging system with a Canon 20Da camera. It is a 60 second unguided exposure.



This next image is similarly another snapshot taken in January of the Rosette Nebula (NGC 2237) . A mostly hydrogen gas cloud, it acted as nursery for the star cluster that condensed from the gas. Shaped like a Christmas wreath, it is observable in the winter season. Similar to above, this is a 90 second exposure with the same hardware. These snapshots are easy with the Hyperstar setup (equivalent to a 660mm lens working at F/1.9) because of the wide field and short exposure. This image shows the light falloff at the upper part of the frame, which can be corrected in the flat fielding. Some day...




Lastly, this lunar shot was taken at the Messier marathon this last Saturday night. It is a .1 second exposure to show the "dark side" of the moon that is illuminated by the nearly full earth from it's perspective. It also shows the almost 2 X 1.3 degree field of view with the nearly half degree orb of the moon. Hardware is the same as above, and only simple levels adjustment was done to better display the images.