M 31 – Great Andromeda Galaxy (19 Oct 2024)

 DSO, Galaxy, General Commentary, Wide FOV  No Responses »
Nov 042024
 

While waiting for my deep space camera to be repaired, I’ve been busying myself with two alternate efforts. One, planetary imaging since Saturn, Jupiter and Mars are in the morning sky. Second, developing the process of using a smaller telescope and a new, to me, deep sky camera. The second effort is the subject of this post.

I’ve always wanted the ability to image larger portions of the sky without resorting to mosaicking smaller images into one larger image. My normal deep sky setup’s FOV is only 24′ (arc minutes) by 16′. This is great for asteroid astrometry but a real pain to get something as large as the Pleiades (M 45) for example.

I have a wide FOV short tube 80mm f/6.0 apochromatic refractor. Paired with a 20-year-old STL-11000M CCD camera, I can now get a 4.3° x 2.8° FOV. So, I am, since I have the time, developing the procedures I need to use this imaging system effectively. Here is one of my first attempts.

M 31 (The Great Andromeda Galaxy) [L: 30x60s] (Mouse over for labels)

This is of course, M 31 – a large spiral galaxy located in the Andromeda constellation. Located 2.5 million light years away, this is the furthest object that can be seen naked eye. You need a clear dark night, but even I have seen the bright core of this galaxy.

Mousing over the image will show labels for several objects associated with M 31. M 32 and M 110 are small satellite galaxies. These are gravitationally bound to M 31 in the same way the large and small Magellanic Clouds are gravitationally bound to the Milky Way. NGC 206 is a large star cloud and is one of the largest and brightest star forming regions in the nearby group of galaxies which includes the Milky Way.

 Posted by at 22:09

NGC 891 (17 Oct 2020)

 DSO, Galaxy  No Responses »
Oct 182020
 

I took a break from planetary imaging last night. This is a target of opportunity I ran across in between asteroid sets. NGC 891 is an edge-on spiral galaxy located in the constellation Andromeda. Also known as the Silver Sliver Galaxy, it was discovered by William Herschel in 1784.

Silver Sliver Galaxy (NGC 891)[CV:52x60s)

There is quite a bit of detail in the prominent dust lane that evenly splits the disk. There is also another edge-on spiral galaxy apparently deep in the background slightly above NGC 891’s disk. It is very small and about half way from the central bulge and the right edge.

 Posted by at 18:05

NGC 7331 and friends (09 Sep 2020)

 DSO, Galaxy  No Responses »
Sep 112020
 

While waiting for an asteroid to come into view, I had enough time to image a target of opportunity. NGC 7331 is a large spiral galaxy located in the constellation Pegasus. As is normally the case, there are several other galaxies visible as well. Just starting to become visible in this image assembled from thirty-one 60 second exposures are three other members of the “NGC 7331 group” (NGC 7337/7335/7336). Although visually close, all the galaxies lie extremely far from each other and only look close from Earth’s perspective.

This image shows a spiral galaxy centered in a sparce field of Milky Way stars. It is slightly tipped towards the observer with the near edge lower. There are sveral other but much cmaller, more distant galaxies.

NGC 7331 [CV: 31x60s]


In the constellation map, NGC 7331 lies at the ‘top’ of Pegasus bordering on the constellation Lacerta (the Lizard).
This is a copy of the primary image with the primary objects identified by their astronomical designations.

NGC 7331 – Annotated [CV: 31x60s]
This is a map of a portion of the northern celestial sphere. The constellation is highlited with the brighter stars connected by lines.

By IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) via Wikimedia Commons
 Posted by at 14:11

Lagoon Nebula and friends (14 Jun 2020)

 DSO, Globular Cluster, Nebulae, Open Cluster  No Responses »
Jun 162020
 

I am still developing the procedures necessary to process one shot color (OSC) camera images. This is the first D90 image I have processed using the color information. The steps to process an OSC camera are totally different than the steps I use to produce color images taken by my science camera. The larger FOV also adds additional complexity. This image is 2.83° wide versus my science camera having an FOV of only 24′ (arc minutes). However, the increased area makes it much easier to image multiple objects without having to assemble a mosaic of smaller images.

This picture is centered on an object in the southern constellation Sagittarius: The Lagoon Nebula. Also known as M 8, it is a large emission nebula being energized by the open star cluster NGC 6530 that lies in it. Also easily visible towards the lower right is M 20 (The Trifid Nebula) containing both emission and reflection nebulae. The small concentration of stars at the upper left is the globular cluster NGC 6544.

Lagoon Nebula (M8) [F:10x120s]


Chart generated by Cartes du Ciel (CdC)

Chart courtesy of IAU/Sky&Telescope

The vertical yellow line that runs all the way through the CdC chart is the ecliptic. Since most asteroids orbit in the plane of the solar system, the image contains a lot of them. I counted 31 identified on the chart by small green dots, but due to the image scale and the asteroid’s magnitudes I couldn’t find any of them.

Both M 8 and M 20 are just visible with binoculars. Using the constellation chart, observe just above the spout of Sagittarius’ Tea Pot asterism (heavy green lines).

 Posted by at 18:45

Wild Ducks and Jupiter (11 Jun 2020)

 DSO, Jupiter, Open Cluster, Planet, Solar System, Wide FOV  No Responses »
Jun 132020
 

While waiting for Jupiter and Saturn to clear my tree line, I did some more testing with my wider FOV scope that has a simple DSLR mounted on it. I am still manually focusing the system but it doesn’t take too long to accomplish. The recently installed flattener corrects the distortion apparent in the stars at the corners of each image.

The target for tonight’s testing was Messier 11 (The Wild Duck Cluster). Legend has it the cluster was given its name by British Admiral William Henry Smyth (1788-1865). When describing the cluster, the Admiral, a very accomplished astronomer and avid hunter, commented the V-shaped group of stars looked like a flock of wild ducks.

Classified as an open star cluster, the flock is located in the constellation Scutum (The Shield). The constellation is right in the middle of the plane of the Milky Way and towards the center of the galaxy. That is fairly apparent by the sheer number of stars in the image. North is to the right putting M 11 right on the northern edge of the Scutum star cloud. The dark area towards the bottom right side of the image is not a lack of stars. It is a large area of dust and gas dense enough to block the light of more distant stars. Several of these areas were individually cataloged as dark nebulae by American astronomer E. E. Barnard, hence the B numbers on the matching chart.

Wild Duck Cluster (M 11) [M:11x120s]

As can be seen on the constellation chart, Scutum is in the southern sky located between Aquila and Sagittarius. The image and matching chart are rotated 90° to the constellation chart.

Chart generated by Cartes du Ciel

Chart courtesy of the IAU and Sky&Telescope

Once Jupiter and Saturn cleared the trees I switched over to planetary equipment and was able to get a couple of series of both planets before wispy clouds moved in from the south. As usual, the best Jupiter image was uploaded to NASA’s JunoCam web page for mission planning.

Jupiter [(V)TR:2506×0.74ms;TG:2501×1.1ms;TB:2505×1.7ms]

 Posted by at 15:32
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