November 23, 2024

M15 – Globular Cluster in Pegasus

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” Baader Fringe Killer (Minus Violet)

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 32x60sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/125s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, very poor transparency, haze, smoke, full moon

Lensed Sky Quality Meter: 17.8 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

M15, a bright, condensed globular cluster in a relatively lonely stretch of sky in Pegasus. It is one of the oldest known globular clusters with an estimated age of 13.2 billion years and the first globular cluster found to have a planetary nebula (Pease 1), one of only four planetary nebula associated with a globular cluster. M15 is also one of the most condensed globular cluster and at some point in the distant past it experienced a core collapse that may have heralded the formation of a black hole in its nucleus. This is supported by the fact the M15 is an x-ray source.

This is the first of two images taken to evaluate the performance of Unitron 510 for imaging and the Baader Fringe Killer Filter. This full-frame field is quite remarkable in that it shows a sharp, high contrast image across the entire field with perfect star shapes. There is still just a tad of violet fringing around some of the brighter stars, but it is much reduced as compared to an image of the same field taken without the filter.

M15 is currently well placed rising the east in the early evening and is high in the south at dawn. (Photo credit: John Graham, 7-30-2023)

NGC 7789 – Open Cluster in Cassiopeia

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” ZWO IR Cut Filter

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 26x60sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/10s sky flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency

Lensed Sky Quality Meter: 18.4 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

NGC7789 is a large and wonderfully rich open cluster located just west of Cassiopeia. It was discovered by Caroline Herschel in 1782 and is sometimes called Caroline’s Rose. It is a delicate object in small to moderate scopes, but blossoms into a rich field in large telescopes. When viewing this cluster I like to spend some time with the field. At first all I will see are the foreground stars and perhaps a soft glow in the background. As my eye adjusts, the first faint stars appear, and then it slowly blooms into a beautiful patch of stardust.

This is the last of 5 test images taken with my Unitron 510. Caroline’s Rose is currently low in the northeast at sunset and is high overhead after midnight. (Photo credit: John Graham, 7/14/2023)

M2 – Globular Cluster in Aquarius

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” ZWO IR Cut Filter

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 24x60sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/10s sky flats taken at dusk

Average Light Pollution: Bortle 8, fair transparency

Lensed Sky Quality Meter: 18.6 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

M2 is a big, beautiful globular cluster that is well placed in the eastern sky in late summer and early fall. It is an easy target for a small telescope. Under dark skies it can even be glimpsed without a telescope or even binoculars. M2 is about 37,500 light years away and lies beyond the galactic center. Like most globular clusters M2 is an ancient relic of the early universe with an estimated age of about 13 billion years.

This is the fourth of 5 test images taken with my Unitron 510. M2 is currently rising in the east in late evening. (Photo credit; John Graham, 7/14/2023)

M27 – The Dumbbell Nebula in Vulpecula

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” ZWO IR Cut Filter

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 11x120sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/10s sky flats taken at dusk

Average Light Pollution: Bortle 8, fair transparency, haze, smoke

Lensed Sky Quality Meter: 18.7 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

M27, the Dumbbell nebula, is an expanding shell of gas that was ejected from a sun-like star as it exhausted its hydrogen fuel. Swollen into a red giant, the star shed its outer shell while its core collapsed into a white dwarf. Fierce UV radiation from the collapsed core sets the surrounds gas aglow with the blue/green light of doubly ionized oxygen. The diameter of the nebula is about 1 light-year with an estimated age of 9,800 years. Located between Sagitta and Cygnus, M27 is fairly easy to find with a small telescope. Visually, it shows two lobes connected by a neck of nebulosity, giving the nebula its characteristic dumbbell shape.

This is the third of 5 test images taken with my Unitron 510. M27 is currently high in the east as the sky darkens. (Photo credit; John Graham, 7/14/2023)

M22 – Globular Cluster in Sagittarius

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” ZWO IR Cut Filter

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 50x30sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/10s sky flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, smoke

Lensed Sky Quality Meter: 18.1 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

M22 is a large, bright, class 7 globular cluster in Sagittarius. With an estimated distance of 10,600 light years it is one of the closer globulars in our galaxy. In many ways M22 should outshine M13, but it can get a bit lost among the stars along the Milky Way near the Sagittarius star clouds and its light is dimmed by dust along the galactic plane. Still, it is large, bright, and easily resolves into this beautiful glow of stardust even in a modest telescope. In a large telescope it blossoms into a glorious sight. This is one of the gems of the summer sky in the northern hemisphere.

This is the second of 5 test images taken with my Unitron 510. M22 is currently rising in the southeast as the sky darkens. (Photo credit; John Graham, 7/14/2023)

M92 – Globular Cluster in Hercules

Telescope: Unitron 510 5” f/16 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” ZWO IR Cut Filter

Guide scope: Williams Optics 50mm Guidescope, ASI290MM, PHD

Exposure: 16x45sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/10s sky flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, smoke

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. This is likely the result the apparent size of M13 being larger than M92 giving M13 a higher total integrated brightness.

This is the first of 5 test images taken with my Unitron 510. The field showed a surprising amount of vignetting, so this image was cropped square to fit within the region that could be corrected with flats. This issue was later traced to a baffle in the draw tube. When this was removed the telescope easily covered the entire full frame.

M92 is currently placed very high in the northeast as the sky darkens. (Photo credit; John Graham, 7/14/2023)

Full Sturgeon Moon – 11:45pm 8/1/2023 EDT

Telescope: Unitron 510 5” f/16, Atlas EQ-G

Camera: Canon EOS Ra

Filter: 2” GSO IR Cut Filter

Exposure: 64×1/250sec, ISO 1600, saved as RAW

Seeing: Fair, 3/5

White Balance: Nebulosity Automatic

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

I stepped outside last night to check on the sky conditions between targets and I found that the smoke and haze were so thick that I decided to call it a night. However, the full moon was so gorgeous I just hand to grab at least one quick set of images. (Photo credit: John Graham, 8/1/2023)

Waxing Gibbous Moon – 9:20pm 7/29/2023 EDT

Telescope: Unitron 510 5” f/16

Camera: Canon EOS Ra

Filter: 2” GSO IR Cut Filter

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

Seeing: Fair, 3/5

White Balance: Nebulosity Automatic

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

This is quick image of the waxing gibbous moon taken last night during dusk. This is one of a series of test images that I and taking to explore the imaging characteristics of the Unitron 510. One nice feature of these long focal length refractors is that they give an excellent well corrected field with little chromatic aberation. (Photo credit: John Graham, 7/29/2023)

M80 – Globular Cluster in Scorpius

Telescope: Meade SN10 at f/4, Orion Atlas EQ-G

Camera: QHY 268c, Mode 0, Gain 30, Offset 30, 0C

Filter: GSO IR Blocking Filter

Guide scope: Williams Optics 50mm, ASI290MM mini, PHD

Exposure: 33x180sec, saved as FITS

Darks: 32×180 sec

Flats: 64×0.1 sec, tee shirt flats taken at dusk

Average Light Pollution: Red zone, poor transparency, low ltitude

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

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Nebulosity, Deep Sky Stacker, Photoshop

M80 is a bright, condensed globular cluster in Scorpius. Containing several hundred thousand stars, it is one of the most densely populated globulars. It is approximately 95 light years across, and 32,600 light years away, about four time farther away than nearby M4.

M80 is currently low in the southeast as the sky darkens.

M57 – The Ring Nebula in Lyra

Telescope: Meade SN10 at f/4, Orion Atlas EQ-G

Camera: QHY 268c, Mode 0, Gain 30, Offset 30, -10C

Filter: GSO IR Blocking Filter

Guide scope: Williams Optics 50mm, ASI290MM mini, PHD

Exposure: 52x120sec, saved as FITS

Darks: 26×300 sec

Flats: 64×0.1 sec, tee shirt flats taken at dusk

Average Light Pollution: Red zone, poor transparency, haze

Lensed Sky Quality Meter: 18.4 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Nebulosity, Deep Sky Stacker, Photoshop

The Ring Nebula is an example of a planetary nebula; shells of gas thrown off from a star late in its light forming an expanding bubble set aglow by the core of the dying star at its center. Visually, The Ring appears as a tiny ghostly smoke ring about the size of Jupiter. The nebula itself is not actually a ring, but more likely a torus or a short hour-glass, we just happen to the looking down the long axis, giving the nebula its characteristic shape.

M57 is well placed throughout the summer months and is currently rising in the northeast as the sky darkens.