November 21, 2024

M81 & 82 – Spiral Galaxies in Ursa Major

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 69x90sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/250sec, ISO 800, sky flats

Average Light Pollution: Red zone, Bortle 8, fair 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, Deep Sky Stacker, Nebulosity, Photoshop

This is M81 (bottom) and M82 (top), two bright spiral galaxies lying about 12 million light years away in Ursa Major. At present, these two galaxies are about 150,000 light years apart, though a few hundred million years ago the two passed very close to each other. The dark dust lane slashing across M82 is one result of this close encounter with M81 as are the blue star formation regions in M81. Visually, M81 and 82 are fairly easy to see with a modest telescope even from my light polluted backyard. M81 shows its beautiful soft core similar to M31 while M82 shows its elongated shape interrupted by the dust lanes giving it a very irregular shape.

M81 and M82 are currently located to the lower right of the bowl of the Big Dipper during the early evening.

M51 – The Whirlpool Galaxy in Canes Venatici

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 33x90sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/250sec, ISO 800, sky flats

Average Light Pollution: Red zone, Bortle 8, poor transparency

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

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

M51 is a beautiful face-on spiral galaxy in Canes Venatici, just south of Alkaid, the bright star that lies at the end of the Big Dipper’s handle. The spiral arm that appears to connect M51 to the nearby companion (NGC 5195) is a bit of an illusion. The companion actually lies behind M51, and if you look closely you can see that the spiral arm is silhouetted against the background galaxy. Modern observations and computer modeling suggest that the companion has made at least two passes through the main disk of M51. During the first, it approached M51 from behind, passed through the face of the galaxy, swung around in an orbit that took it in front, and then back through the disk where it lies now behind M51. These passes set off bursts of star formation that gives the arms of M51 their beautiful blue color.

M51 is located just off the end of the handle of the Big Dipper high in the northwest as the sky darkens.

M92 – Globular Cluster in Hercules

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 69x30sec, gain ISO 800 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 32x1sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky 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.

M92 currently rises in the northeast during the early evening.

M13 – Globular Cluster in Hercules

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 57x30sec, gain ISO 800 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 32x1sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

This is M13, the Great Cluster in Hercules. Also in the picture is the galaxy NGC 6207 (Mv 11.6) in the upper left along the top edge of this field, and about halfway between NGC 6207 and M13 is the tiny galaxy IC 4617 (Mv 15.2) . If you look carefully at M13 you can see a dust lane to the lower left of the cluster. This 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.

NGC 95 & 96 – Spiral Galaxies in Leo

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 36x60sec, gain ISO 1600 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 32x1sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

M95 (right) and 96 (left) are a relatively faint spiral galaxies in Leo. M95 shows a fascinating variety of detail including a compact ring of star formation surrounding the core and a golden bar connecting the core to the nearly circular, tightly wound inner spiral while M96 shows a faint, sweeping outer veil.

 

NGC 4565 – The Needle Galaxy in Coma Berenices

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 78x60sec, gain ISO 1600 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 32x1sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

NGC 4565 is a relatively bright edge-on spiral galaxy in Coma Berenices. Glowing at a visual magnitude 9.6 it makes a fine target for modest size telescopes. It is thought that our own Milky Way galaxy would appear similar to the Needle Galaxy when viewed edge-on. It’s neat to see how these big beautiful spirals that appear so expansive when viewed face-on are actually relatively thin when viewed edge-on. NGC 4565 also shows a prominent dust lane common to most spiral galaxies. This galaxy is currently well placed in the evening sky on the northern fringe of the Melotte 111 star cluster, itself a beautifully rich region in binoculars and small telescopes.

NGC 2903 – Spiral Galaxy in Leo

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 48x60sec, gain ISO 1600 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 64×1/250sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.5

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

NGC 2903 is a fairly bright (Mv 9.0) galaxy located just south of the head of Leo (the Lion). The galaxy is 20.5 million light years away and is 80,000 light years across, making it a little slammer than the Milky Way. I first spotted this galaxy while star-hopping around Leo and Cancer. It is an easy target in an 8” scope where I was able to clearly see the core and bar. The sweeping arms are gorgeous in the photograph, but they are not visible from my backyard.

NGC 2903 is currently well-placed rising in the east during the early evening.

NGC 2261 – Hubble’s Variable Nebula in Monoceros

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 56x60sec, gain ISO 1600 saved as RAW, dithered every 2 images

Darks: Internal

Flats: 64×1/250sec, Tee shirt flats taken at dusk

Average Light Pollution: Red zone, Bortle 8, poor transparency

Lensed Sky Quality Meter: 18.3

Stacking: Average, 1 sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, 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 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 nebula. Visually, NGC 2261 appears very much like a beautiful fan-shaped comet. In fact, it appears more like a comet than some comets!

NGC 2261 is presently rising in the east as the sky darkens.

M81 – Spiral Galaxy in Ursa Major

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

Camera: Canon EOS Ra full frame DSLR

Filter: 2” Baader Fringe Killer (minus V)

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

Exposure: 47x60sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 64x1/125s 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

This is the last image in this image set taken with the Unitron 510.

M81 is a beautiful spiral galaxy that is interacting with the nearby M82. The sky conditions for imaging this delicate galaxy were far from optimal, but it is still neat to see the beautiful sweeping arms sprinkled with star forming regions resulting from a close encounter with M82. Very pretty.

M81 is low in the northeast during the early evening and is high overhead after midnight.

NGC 2392 – The Eskimo Nebula in Gemini

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

Camera: Canon EOS Ra full frame DSLR

Filter: 2” Baader Fringe Killer (minus V)

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

Exposure: 67x30sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 64x1/125s sky flats taken at dusk

Average Light Pollution: Bortle 8, fair transparency

Lensed Sky Quality Meter: 18.5 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

NGC 2392, Eskimo Nebula, is a wonderful little planetary nebula Gemini. Visually this nebula looks much like its nickname, even in a small telescope. Planetary nebula are formed when a star sheds its outer shell as it nears the end of its life while the core collapses into a fiercely bright white dwarf whose intense radiation sets the expanding shell of gas aglow, often with a beautiful blue/green color. The structure of NGC 2392 shows that it experienced several shedding events.

The Eskimo Nebula is currently well placed in the east during the early evening and a fairly easy target for small telescopes.