Astrophotography – Page 20

An Evening with a New Telescope

The Astro-Tech 6″ RC is a wonderful little telescope… A true Ritchey–Chrétien design, at a size well matched to DSLR astrophotography. It was get one now or never, these were the last of the production run, and now they are gone.

Best of all, Astronomics was letting them go at a fire sale price… Less than $300 each!! It may have taken months on a waiting list, but I finally received one. Then it took another two months of waiting for some necessary accessories to make it work! No problem with the wait, I was patient… mostly.

With the final parts, the extension tubes, in hand. I determined to spend part of my four day Thanksgiving weekend getting the new ‘scope into service.

The Orion Nebula — NGC1976 or M42, the Great Orion Nebula, sum of 113 frames at 35x5min, 38x1min, 20x20sec, and 20x5sec. Taken with the Canon 20Da and a AT6RC telescope.

It took hours to rearrange the setup, un-bolting and re-bolting telescopes to and from the plates of aluminum that hold everything. Carefully aligning each of the four items in the setup… Main telescope, guide telescope, the finder CCD camera and a Telrad. Finding the best focus, recollimating the 6″RC, re-balancing the mount, fixing a computer power supply issue, rearranging and tying up all the myriad of cables, etc. etc… Astrophotgraphy really is the art of endless details. Finally, late into the evening, I took the first test image.

A few images later and things were not looking all that bad, maybe even functional. Better yet, my venerable ST-4 autoguider seemed to be tracking well. Maybe take a real picture? What to shoot? Something easy… M42 was rising over the garage… Why not? Just a test for the new setup, a fair chance something will go horribly wrong.

AT6RC & ZEQ25 — AT6RC atop an iOptron ZEQ25 mount

Result? Not too bad. This is despite many shortcomings… I forgot to take raw images, thus I had to process from the JPEG’s. I didn’t get any decent calibration frames. There seems to be substantial flexure between the guide ‘scope and the imaging ‘scope, but it is slow and does not effect individual frames. Actually the registration drift over the hours helped me process out the hot pixels and other image artifacts by creating an effective dithering. I did lose a few frames to vibration, the mounting could be stiffer, and I must be careful to walk softly on the concrete slab of the driveway during exposures.

But still, not bad for a first real attempt.

The stars look nice across the frame, showing that the collimation is decent, always an issue with the RC design. I suspect the optical quality of the telescope is quite acceptable. The brighter star images are a bit “fat” but that is due more to the mediocre seeing over Waikoloa. After all of these years shooting with a refractor, I had forgotten how pleasing diffraction spikes can be. Better yet, with the scope positioned for north up on the tube, the spikes are neatly at 45° to the cardinal directions. I am looking forward to some more imaging sessions with a new telescope.

Postcard from the Universe – Sunspots

As we approach solar maximum, large sunspot groups have again become a common sight. The last few years have seen an unusually quiet solar minimum, long stretches of time when not a single sunspot appeared. that has certainly changed, the Sun is now dotted with sunspots, with the occasional monster. At it’s peak, AR1339, seen above, was over 100,000km across. That is larger than 15 Earths, side by side. I mean monster!

The photo was taken with the Canon 60D, a 0.8x TeleVue adaptor, a C-11 and a Thousand Oaks full aperture solar filter.

Sunspots — Sunspot group AR1339 as seen on the afternoon of 5Nov2011

Postcard from the Universe – Pleiades

Yes, I have shot the Pleiades many times before. Still, a nice test of the new camera. I was limited to short exposures, 2 minutes in this case, as I was not setup for guiding. I took more frames instead, over thirty exposures of two minutes each for an hour total. After throwing a few out I still had enough to beat down the noise. I expect that with guiding and longer exposures the result would be better, but this wasn’t too bad…

Postcard from the Universe – The Tarantula from Hawaiʻi

OK… It is a crappy astrophoto.

But it does prove one thing, you can see the Large Magellanic Cloud from Mauna Kea… Barely.

The photo was taken from the Mauna Kea VIS parking lot as the LMC rose above the slopes of Mauna Loa. As the object skirted the distant ridge line I shot a dozen frames with the 60D and the TV-76mm scope. The resulting photo is nothing to be proud of, I expected it to be pretty bad when I shot it. It was taken simply to prove the point.

Tarantula NGC2070 — The Tarantula Nebula, NGC2070, rising above the slopes of Mauna Loa

Earthshine

Supernova 2011fe in M101

I have been watching the supernova nearly since it erupted around 23 Aug. We first viewed the supernova on 26 Aug using Cliff’s 24″ scope in the schoolyard of Waikoloa Elementary. I have since seen it about half a dozen times, as it brightened and peaked at around 10th magnitude in mid September. The supernova has since dimmed somewhat, now about 11.5 magnitude, but still quite easy to find with a small telescope. It is brighter than the host galaxy, M101.

Not a great picture. The galaxy was setting and I was shooting as it slid behind the shoulder of the mountain. All I could manage was a quick sequence of a dozen 30sec images. Still, you can actually see the galaxy and supernova. The image is much as it appears in a larger telescope around 14-20″ of aperture under a dark sky.

SN2011fe in M101 — Type Ia supernova, SN2011fe, in the galaxy M101

Postcard from the Universe – Jupiter and Moons

A nice image of Jupiter with the moons (left to right) Europa, Ganymede and Io. Taken early Sunday morning from Hale Pohaku. Conditions were quite nice, both for photography and simply observing by eyeball through the telescopes set up.

The telescope used is not mine, but belongs to fellow club member, Maureen. We had just collimated the ‘scope, aligning the optics for optimum performance. I wondered just how good the performance might be. The answer? Pretty good!

I used the Canon 60D to shoot the video. The ‘scope was a Celestron 9.25″SCT operating at f/10. The camera has a 640×420 cropped video mode that is ideal for this sort of use. Shooting at 60fps it generates very high quality video.

The frame is a stack of 900 frames selected from well over 1500 frames in the source video. The result is quite pleasing, particularly the moons. Three of the four large Jovian moons are visible. They appear as disks, with the larger Ganymede notably bigger than the smaller Io. The disk of Jupiter shows good color and cloud formations. Overall the result is excellent and shows the promise of using the DSLR to shoot planetary video. I will be experimenting with this method and expect even better results in the future.

Jove — Jupiter and the moons Europa, Ganymede and Callisto (left-right)

Shooting in the Dark

A supernova, a comet, a new camera and a dark night.

I have had the Canon 60D for a while now. Since April in fact. It was my main carry camera in Alaska this summer. This was the camera used to produce the laser shots and videos that were published far and wide. But I have never used the camera on a telescope. A new Moon observing weekend is an opportunity to change that.

Astrophoto Setup — The NexStar 11″, the TV76mm and a Canon 60D setup for astrophotography at the MKVIS

I have recently re-assembled my astrophotography rig in the garage. But that rig has some technical issues that need to be solved before it is ready to use. Instead I packed up the NexStar 11″ scope, a scope usually used for public observing, but also a nice photographic platform. Piggyback the TeleVue 76mm atop the larger scope, attach the 60D and I am ready to shoot. Well? Maybe a bit more work than that. With alignments, focusing and more it was an hour before the first exposure.

While my camera was busy shooting sequences, I wandered around and visited with the other folks enjoying the night. A few peeks through other scopes at favorite objects was about all the visual observing I did. There were a couple groups using cameras without telescopes to shoot stars capes under the dark sky. We traded hints as multiple cameras worked the night.

An orange glow in the clouds betrayed new lava flows on Kilauea. Even thirty miles away we could make out bits of a channelized a’a flow. The pair of binoculars I had brought became one of the most popular optical instruments around.

I was using the rig without any autoguiding, as a result guiding errors spoiled a number of exposures. I kept the exposures short, and shot bright objects. I have sequences to process of a lot of old favorites… M31, M42, a few open clusters like M11 and M38, the Pleiades and more. Just before dawn I even shot a sequence of the Tarantula Nebula skimming the slope of Mauna Loa. Two 8Gb SD cards filled and part of a third. I will be some time processing the many images taken through the night. There is even some video of Jupiter and Mars to process into high resolution planetary images.

There were three telescopes still operating when dawn appeared. Maureen, Cliff and myself watched as the sky grew bright and a thin crescent Moon rose above the slopes. Even then we spent a little time observing and photographing the Moon or Mars as the stars disappeared. We were still breaking down gear as sunlight swept the hillsides around us. Tired and yet elated we greeted the Sun.

The usual suspects setting up gear for a great night of observing on Mauna Kea...

Omega Centauri

Postcard from the Universe – 103P/Hartley 2

I am waiting for the Moon to leave the evening sky before shooting the comet again. In the meantime I am processing more of the material obtained earlier in the month. In this case a photo of Comet 103P/Hartley 2 taken October 6th with Keck 2 and DEIMOS. The image marks the first time I have attempted to take and process an image with a 10m telescope. Just a wee bit larger than the 76mm refractor I usually use to take astrophotos!

The image is notable for its complete lack of any interesting structure. There are no jets, shells or other inner coma detail visible. The tail is simply a general brightening to the southwest (lower right in this image).

The comet is moving very quickly across the sky, even more so with the high magnification lent by a large telescope. Even short exposures turn the stars into long streaks. In this case multicolor streaks as the camera cycles through the filters needed for a color image.

103P/Hartley 2 — Comet 103P Hartley 2 with Keck2 and DEIMOS 6Oct2010 @ 7:27UT, 3x60s, 3x60s and 3x120s with standard BVR astrometric filters, credit: Cooper/Wirth/W.M. Keck Observatory