November 23, 2024

M92 – Globular Cluster in Hercules

M92 – Globular Cluster in Hercules

Telescope: Stock Unitron 155c 4” f/15 refractor

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: None

Exposure: 27 (of 32)x15sec, ISO 6400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/20s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, low altitude

Lensed Sky Quality Meter: 18.3 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

M92 is the ‘other’ globular cluster in Hercules. M92 lies to the northeast of the popular M13 globular cluster in a relatively lonely patch of sky making it a bit harder to locate, but well worth the effort. Interestingly, M92 is listed as being fainter than M13 (Mv 6.4 for M92 vs. 5.8 for M13), but I find the core of M92 to be a tad brighter than M13. The larger apparent size of M13 likely contributes to its slightly higher total integrated brightness.

This is the 3rd and last test image taken with my Unitron 155c in its stock configuration. Next up; moving the 155 over to my Atlas to see what it can do on a modern guided mount.

M91 currently rises in the northeast during the early evening.

M13 – Globular Cluster in Hercules

M13 – Globular Cluster in Hercules

Telescope: Stock Unitron 155c 4” f/15 refractor

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: None

Exposure: 28 (of 32)x15sec, ISO 6400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/20s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, low altitude

Lensed Sky Quality Meter: 18.3 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

This is M13, the Great Cluster in Hercules. If you look carefully you can glimpse the tiny galaxy NGC 6207 (Mv 11.6) in the upper left corner as well as a dust lane to the lower left of the cluster. The dust lane is a very unusual feature for globular clusters and it is not clear if this is actually associated with M13 or simply lies in the line of sight with the cluster.

M13 currently rises in the northeast during the early evening.

M3 – Globular Cluster Canes Venatici

M3 – Globular Cluster Canes Venatici

Telescope: Unitron 155c 4” f/15

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: None

Exposure: 24 (of 32)x15sec, ISO 6400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/20s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, low altitude

Lensed Sky Quality Meter: 18.2 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

This is the first test image taken with my Unitron 155c using it in it’s stock configuration with it’s original German equatorial mount ans synchronous clock drive. I was pleasantly surprised that the telescope was very easy to point using the setting circles and it was relatively easy to find and center the target. The tracking was very good and similar to modern unguided mounts. I found that I could get 70%-90% successful subs using 15 second exposures. Once the drive settled down 80-90% was more typical. Polar alignment using a QHY Polemaster was quick, easy, and accurate. This is a pre-1966 model which does not have a slow motion adjustment for the R.A. once the clock drive is installed, but I found that all I had to do was to point the telescope slightly east of the target and then turn the clock drive off, let it drift to the center of the field, and then turn the clock drive back on. The drive ran perfectly off of the 120VAC output from my lithium ion battery. The field of view of the EOS Ra was generous and the camera was sensitive enough to show the target on the screen in the live view frame and focus mode.

M3 is a beautiful example of a globular cluster in a relatively lonely stretch of sky. The cluster is a member of the galactic halo and spends much of its time orbiting well outside the plane of the galaxy. It is presently 33,000 light years away from us, 40,000 light years from the galactic core, and 33,000 light years ‘above’ the galactic plane. Home to about 500,000 stars, M3 is relatively young as globular clusters go with an estimated age of 8 billion years.

M3 is currently well placed rising in the northeast during the early evening.

Full Moon – 10:30pm 4/16/2022 EDT

Full Moon – 10:30pm 4/16/2022 EDT

Telescope: Unitron 155c 4” f/15

Camera: Canon EOS Ra

Filter: 2” GSO IR Cut Filter

Exposure: 64×1/500sec, ISO 1600, saved as RAW

Seeing: Poor, 2/5

White Balance: Nebulosity Automatic

Software: Backyard EOS, Autostakkert, Registax, Nebulosity, Photoshop

This is quick image of the full Pink Moon taken with my Unitron 155c and Canon EOS Ra.

Sigma Orionis – Multiple Star System in Orion

Sigma Orionis – Multiple Star System in Orion

Telescope: Unitron 155c 4” f/15

Camera: Canon EOS Ra, Interval Timer (no computer)

Filter: 2” GSO IR Cut Filter

Guide scope: None

Exposure: 32x1sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: None

Average Light Pollution: Bortle 8

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

Sigma Orionis is one of my favorite fields in the winter and spring sky. Sigma itself can be easily spotted with your unaided eye as a modest star just south of the easternmost star in Orion’s Belt; Alnitak. In a small telescope Sigma shows two nearby companions just off to the northeast as well as a wide pair off to the northwest (Struve 761). Close examination in a larger telescope shows a third companion to Sigma close by to the southwest, making Sigma a quadruple star system, and the southern star of the northwestern pair splits into a beautiful close pair of equal stars, making this a wonderful field of 7 closely arranged stars. (The brightest component of Sigma is actually a close binary system, making this a quintuple system!) During the winter months I always take a minute to stop by and to visit these old friends and I often use them to take a quick peek at the quality of the optics in a newly acquired telescope.

Sigma Orionis is currently well placed high in the southwest at dusk.

Earthshine – 9:00pm 4/3/2022 EDT

Earthshine – 9:00pm 4/3/2022 EDT

Telescope: Unitron 155c 4” f/15

Camera: Canon EOS Ra, Interval Timer (no computer)

Filter: 2” GSO IR Cut Filter

Exposure: 16x2sec, ISO 1600, saved as RAW

Seeing: Fair, 3/5

White Balance: Nebulosity Automatic

Software: Registax, Nebulosity, Photoshop

After taking a set of images of the crescent moon I decided to try and capture the beautiful Earthshine. The source images were gorgeous without a hint of color fringing. I had to remove a ghost image that indicates that the objective in this old Unitron does not have AR coatings. Processing also brought up a little bit of color fringing, but it is still very limited. Note the little star trail just above the moon that shows how far the moon moved during the time the source images were being taken.

Waxing Crescent Moon – 9:00pm 4/3/2022 EDT

Waxing Crescent Moon – 9:00pm 4/3/2022 EDT

Telescope: Unitron 155c 4” f/15

Camera: Canon EOS Ra, Interval Timer (no computer)

Filter: 2” GSO IR Cut Filter

Exposure: 32×1/50sec, ISO 800, saved as RAW

Seeing: Fair, 3/5

White Balance: Nebulosity Automatic

Software: Registax, Nebulosity, Photoshop

This is quick test image taken with my 60 year old Unitron 155c on its second night out. During this test I found that the 155c was much easier to point and to fine tune the field than I had expected. I was particularly interested in whether I could make fine adjustments in the R.A. as this model lacks the secondary fine R.A. control meaning that you cannot make fine adjustments in R.A. while the clock drive is installed. This turned out not to be a problem. The field of view of the full frame EOS Ra is large enough that pointing the scope was relatively easy. To make fine adjustments in R.A. I simply pointed the scope slightly west of the target, and then turned the clock drive off, letting it drift to the center of the field, and then turning the clock drive back on. Easy peasy. The clock drive itself performed flawlessly off of the 120vac output from my lithium ion battery pack, though I need to work on the polar alignment to get the best performance from it. It is certainly plenty good enough for visual and if I get serious about imaging with this scope I should look at mounting it on my Atlas.

M67 – Open Cluster in Cancer

M67 – Open Cluster in Cancer – Unitron 142 3” f/16 Refractor

Telescope: Unitron 142 3” f/16 Refractor

Camera: ZWO ASI294MC (uncooled)

Filter: Meade IR Cut Filter

Guide scope: None

Exposure: 32x10sec, Gain 200, saved as PNG

Darks: None

Flats: Synthetic

Average Light Pollution: Red zone, poor transparency, haze

Lensed Sky Quality Meter: 18.4

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Nebulosity, Photoshop

M67 is one of my favorite modest open clusters. It is located off to the east of the much larger and brighter M44 (The Beehive) and it is a bit harder to find, but worth the effort. M67 is very old for an open cluster with an estimated age of about 4 billion years. The stars in an open cluster are usually only weakly bound to the group and they slowly scatter as the cluster orbits the galaxy.

High in the southeast this time of year, M67 makes a fine target for modest telescopes and blossoms into a fine patch of stardust in large telescopes.

M3 – Globular Cluster Canes Venatici

M3 – Globular Cluster Canes Venatici – Unitron 142 3” f/15 Refractor

Telescope: Unitron 142 3” f/15 Refractor

Camera: ZWO ASI294MC (uncooled)

Filter: Meade IR Cut Filter

Guide scope: None

Exposure: 32x10sec, Gain 200, saved as PNG

Darks: None

Flats: Synthetic

Average Light Pollution: Red zone, poor transparency, haze, low altitude

Lensed Sky Quality Meter: 18.0

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Nebulosity, Photoshop

M3 is a beautiful example of a globular cluster in a relatively lonely stretch of sky. The cluster is a member of the galactic halo and spends much of its time orbiting well outside the plane of the galaxy. It is presently 33,000 light years away from us, 40,000 light years from the galactic core, and 33,000 light years ‘above’ the galactic plane. Home to about 500,000 stars, M3 is relatively young as globular clusters go with an estimated age of 8 billion years.

This is one of a series of ‘just for fun’ images taken with my 50 year old Unitron 142 3” f/15 refractor. I was pleased to find that the overall tracking quality of this mount is comparable to many modern mounts suggesting that it could be used for basic imaging using modern camera and processing techniques. So far the results have been surprisingly good and a lot of fun!

M3 currently rises in the northeast during the late evening.

NGC 2261 – Hubble’s Variable Nebula in Monoceros

NGC 2261 – Hubble’s Variable Nebula in Monoceros

Telescope: 8” Meade Wide Field LX200GPS @ f/6.3 (Native), altaz mode

Camera: ZWO ASI 294MC, Baader Mk III MPCC

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 2,020x1sec, Gain 400, saved as TIFF

Darks: None

Flats: Synthetic

Average Light Pollution: Red zone, Bortle 8, fair transparency, bright moonlight

Lensed Sky Quality Meter: 18.2

Stacking: SharpCap Pro, real-time

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Nebulosity, Photoshop

Hubble’s Variable nebula is a small, bright, fan-shaped reflection nebula in Monoceros (the Unicorn). The bright tip of the nebula is not just a star, but a dense nebula hiding a binary star system at its core (R Mon). Clouds of dust are believed to orbit this system, casting shadows up onto the veil causing the overall brightness of the nebula to vary. Time lapse sequences spanning weeks of time show the shadows sweeping across the veil.

In some ways this is the most remarkable image. I set my gear up to continue testing this system for remote observing using short exposures (0.5-5 seconds) either in live view or live stacking in SharpCap Pro. I had to step away for a while, so I left the system pointing at NGC 2261 with SharpCap Pro live stacking 1 second exposures. When I came back I found that it was happily stacking away passing through 2,000 frames. The image on the screen looked fantastic, so I had it save the screen as-shown as a TIFF, and finished it off in Nebulosity and Photoshop. This is evolving into a very powerful remote observing and imaging system and I’ll probably be using it a lot more in the future.

NGC 2261 is currently well placed in the evening sky rising in the east as the as the sky darkens.