The Coathanger

Seems like this year has been an interesting one for astrophotography. Either the skies are cloudy, or they are very clear but during the full moon. What to do. 

Well, when the sky is bright and deep sky imaging is not ideal, it is an opportunity for imaging some of the brighter objects the universe has to offer. In this case the Coathanger.

The Coathanger
September 10, 2022 - WO GT102/ASI2600mm
f/5.6 107 minutes

The Coathanger is not a constellation, but a pattern of stars that is not one of the traditionally established, named constellations.  These collections are known as asterisms. It is a small collection of physically unrelated stars, also known as Brocchi’s cluster and Collinder 399. Although It looks very much like its namesake, and easy to make out with a pair of binoculars, you will need a dark sky and know just where to look.

DART Hits Dimorphos

Certainly not of the level of technology that Captain Kirk discovered on Miramanee's planet, which was ultimately used to save her planet from doom (that was science fiction of course) but impressive nonetheless was the successful impact of DART – the Double Asteroid Redirect Test on Dimorphos, a small asteroid moon of Didymos. DART struck the little asteroid – hoping to nudge it slightly off-orbit – at 7:14 p.m. ET (23:14 UTC) on Monday, September 26, 2022.

Didymos-B aka Dimorphos

I remember back in the day discussing the unlikelihood of anything that could redirect an asteroid, but here we are, a first test of doing that very thing. Now this asteroid is very, very small compared to the one on that Star Trek Episode (The Paradise Syndrome, which aired Oct 4, 1968) but it is a first ever to test the viability of redirecting an asteroid impact threat to Earth. 

NASA has a number of images and videos of the impact. 

Here is the series of stills taken as DART approaches Dimorphos.

And here is a actual view from the Asteroid Terrestrial-impact Last Alert System (ATLAS): A NASA and University of Hawaii project to patrol the sky every night in search of incoming asteroids as DART hits the asteroid.

EarthSky has a good writeup on the mission. We won't know for sure yet if the mission was a complete success. We need to wait for data to come in on the change in Dimorphos' orbit. 

The Eastern Veil and the 'Bat'

Yikes.  It's been almost two months since my last post. Have I been that busy on other things? Why, YES. Work, gardening, my retirement business, church activities and a new puppy. Now that's a lot of things keeping me busy.

Cloudy skies for most of the time made imaging a real challenge. But I did get in a few objects; just took awhile to find the time to process them. Turns out that a recent image run is what I processed first. So here it is: the Eastern Veil nebula and a starless cropped close up of the section known as the 'Bat'.

The Eastern Veil Nebula is part of the larger Veil Nebula, a cloud of ionized gas and dust. It is located in the constellation Cygnus the Swan.  This object is actually the visible portion of the much larger Cygnus Loop, which itself is a supernova remnant.

Eastern Veil - GT102/ASI2600 - f/5.6
August 19, 30 and 31, 2022
46x300sec Ha; 46x300sec Oiii; 20x60sec RGB

The star that was the source of the supernova weighed in at 20 times more massive than the Sun and exploded some 10,000 to 20,000 years ago. If you were living at that time you would have seen an object in the daytime sky that would have been brighter than the planet Venus. During the 20,000 years since the explosion the remnants of that star have now expanded to an area roughly 3 degrees in diameter (six times the size of the Moon). It is estimated to be about 2,400 light-years distant.

This rendition is a combination of the Ha and Oiii narrowband (HOO) palette combined with RGB stars.  A total of 8 hours integration of the narrowband and 1 hour for the stars.

The lower section of the nebula is known as the 'Bat'. I cropped the original NB image to capture just the Bat and removed the stars to produce a starless version. I generally don't like starless astrophotos but this nebula looks pretty good when portrayed starless.

The "Bat"

First full color image from the James Webb telescope

Well here it is. The first full color infrared image released from the James Webb telescope. And it’s awesome! This is a region of the sky that represents an area the size of a grain of sand held at arm’s length.

Each of those colorful ellipses and oblong objects are distant galaxies. Only the bright objects with the diffraction spikes are local stars from our own galaxy. And the curved sections around the middle is a even more distant galaxy whose light is being gravitationally bent by a foreground galaxy allowing it's faint light to be magnified and made visible. 

Wow - can't wait for more - and there is more to come for sure!

Full details can be read at NASA and here at SkyandRockets.

First James Webb image to be released today

NASA

The first full color image from the new James Webb telescope will be announced later today. The image, known as “Webb’s First Deep Field,” will be the deepest and highest-resolution view of the universe ever captured. Biden is scheduled to release it today, Monday, July 11, at 5:00pm.

Details on the Webb telescope can be found at nasa.gov

Comet C/2017 K2 (PANSTARRS)

C/2017 K2 (PanSTARRS) is an Oort cloud comet with an inbound hyperbolic orbit, discovered in May 2017 at a distance beyond the orbit of Saturn when it was 16 AU (2.4 billion km) from the Sun. It had been in the constellation of Draco from July 2007 until August 2020. As of June 2022, the estimated distance of the comet from the Sun is ±5000 km. The comet is record breaking because it is already becoming active at such a distance. Only comet Hale–Bopp produced such a show from that distance with a similar nucleus. However, this comet will not be as visible as Hale–Bopp was in 1997 in part because it does not come nearly as close to the Sun.

Comet C/2017 K2 (PANSTARRS)
June 25, 2022
GT102 - ASI533MC - 50x180 sec exposures

On its way to perihelion, C/2017 K2 is currently shining at about mag 7. Missing is the typical greenish glow of a comet's halo that comes from diatomic carbon (C2), a simple yet unstable form of elementary carbon. C/2017 K2 is too far from the sun for the reaction to occur.

M20 - The Trifid Nebula

With the pier maintenance completed it was time to start imaging again.

The Trifid Nebula (catalogued as Messier 20 or M20 and as NGC 6514) is an H II region in the north-west of Sagittarius in a star-forming region in the Milky Way's Scutum-Centaurus Arm. It was discovered by Charles Messier on June 5, 1764. Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula (the relatively dense, reddish-pink portion), a reflection nebula (the mainly NNE blue portion), and a dark nebula (the apparent 'gaps' in the former that cause the trifurcated appearance, also designated Barnard 85). Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers. (wiki)

Trifid Nebula (M20) - June 27, 2022
William Optics GT102 and ASI533MC Camera
146x60 sec at f/5.5

My image of the Trifid is part of a study I am conducting on the benefits of taking lots of short exposure subs vs a moderate amount of longer exposure subs. Longer subs are prone to satellite and aircraft crossings, clouds, and other image corrupting events, and inaccurate guiding (although my AP1100 mount produces almost perfect guiding). So, it would be really good if you could, say for example, take a hundred 30 second subs and make it produce as good a final image as ten 300 second subs - the total integration time is the same; 50 minutes. 

Preliminary results are encouraging as demonstrated by the image above which was processed as 146 single 60 second broadband subs. Narrowband imaging requires substantially longer subs to collect sufficient light through the special filters and so would not benefit from this technique. But OSC (one shot color) and LRGB filtered mono cameras would benefit.

Check back later when I post the complete study results.

Pier Maintenance Completed

The new pier pads have been completed and the telescope mount re-assembled. I was able to spend a few hours recalibrating and realigning the scope this past Monday. First new photos will be attempted this weekend.

New Pier Pads Installed

As reported in my previous blog, I have been having problems with moles digging in under my telescope pier. I finally found the time to make the repairs.

I decided to do the construction in the same location as the original mount to keep from having to redo the Lat/Lon data used in all my software. Each footing was dug in about a foot into the ground at each tripod leg location. 

Once the holes were dug, I removed the layer of grass completely around the pads. 

Then, paver base was poured into each hole and tamped down. I ended up using sufficient base to go to a depth of 10"-12"; a bit overkill, but I had the material.

Next, paver sand was placed at a depth of 1".

The plan was to use 12"x12"x1.5" paver stone to support the tripod pier. I needed three at the southern point and two at the other locations to handle the ground grade. I was concerned that the stones would slide on each other, so I cemented them together with stone mortar. Paver sand was tamped in around each set of stones.

Finally, ground cover to prevent grass and weeds from growing and ornamental marble gravel was spread around the entire area.

The pier was placed on the pads and adjusted to line up true north. The first section of the telescope mount was attached and alignment was double-checked. I needed to move the legs slightly, so they are not perfectly centered on the stone pads, but this is not a problem. 

Next, the wiring needs to be installed and the second section of the mount connected. But that is for another day.

One more galaxy before telescope maintenance

With the moles digging in under my telescope mount, it has finally got to the point where I need to dismantle my telescope setup and construct a new foundation. With the ground softened up with the rain and the full moon coming up this is an ideal time to do the work. So this is the last image for awhile. 

Messier 82 (also known as NGC 3034, Cigar Galaxy or M82) is a starburst galaxy approximately 12 million light-years away in the constellation Ursa Major. A member of the M81 Group, it is about five times more luminous than the Milky Way and has a center one hundred times more luminous. The starburst activity (deep red structures blowing up to either side) is thought to have been triggered by interaction with neighboring galaxy M81. As the closest starburst galaxy to Earth, M82 is the prototypical example of this galaxy type (wiki).

M82 (Cigar Galaxy) - May 10, June 4,5,6, 2022
EdgeHD11; ASI2600mm at f/10
4 hours Ha; 4 hrs RGB color
https://astrob.in/mhkrsd/0/

Imaging this galactic wonder was rather easy as M82 is fairly bright. Getting the starburst regions to show was a challenge in post-processing. The main galaxy was imaged in RGB. The starburst regions were captured in Ha. But the Ha was also fairly prominent in the galaxy's central core and extremes. Normal HaRGB combination techniques gave the whole image a pinkish cast. So I had to crop out and adjust the saturation levels of the Ha master prior to combination with the RGB color master. Took a bit of time, but the result was  pleasing.

Hopefully the maintenance on the mount and scope wont take too long and I'll be imaging again come next new moon in a couple of weeks.

No meteor storm, but a good galaxy image!

Well the potential meteor storm didn't pan out - not that I was surprised.  But I did have the telescope out imaging that night so I was able to capture the Needle Galaxy with my new ASI533MC camera. 

Needle Galaxy (NGC 4565)
May 29-30, 2022
EdgeHD 11; ASI533MC (73x180sec subs)

NGC 4565 (also known as the Needle Galaxy or Caldwell 38) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. It lies close to the North Galactic Pole and has a visual magnitude of approximately 10. It is known as the Needle Galaxy for its narrow profile. First recorded in 1785 by William Herschel, it is a prominent example of an edge-on spiral galaxy. (wiki)

This image run was to be another test of my ASI533MC camera, and the results have really panned out to be above my expectations. This camera, unlike my ASI2600 and ASI1600, is a OSC (one shot color) sensor (similar to a standard digital camera). This makes capturing and processing the astro-images much easier and less time consuming at the expense of not being able to image through NB filters, or take advantage of the higher sensitivity of the monochrome sensors in the 1600 and 2600. It also sports a square image sensor, which takes a bit getting used to. 

The ASI533MC was actually purchased for a number of reasons. First of all, for cometary imaging you don't have to deal with the three RGB filters and can spend the time capturing lots of single color subs. And since comets move noticeably in their orbits while being imaged, dealing with single color subs makes it a whole lot easier to process the final image. Second, it is planned to be added to my new wide field portable telescope for ease of transporting and operation in the field. And finally, it can used in the Hyperstar setup on my EdgeHD 11 for super fast, f/2 imaging with an 11" aperture telescope.

Hopefully in the coming months I'll be able to try out all three of these uses to see how well the ASI533MC performs.