November 25, 2024

NGC 7635 – The Bubble Nebula in Cassiopeia

NGC 7635 – The Bubble Nebula in Cassiopeia

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 15x180sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.0

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

NGC 7635 is almost the inverse of a planetary nebula. Planetary nebula are expanding shells of gas shed from a dying star. The Bubble Nebula is formed from the intense radiation a hot blue star pushing out a sphere in the surrounding gas, making an empty bubble and setting the hydrogen aglow with a beautiful red color. This wide field view includes the open clusters M52 (upper left) and NGC 7510 (lower right), and the emission nebula NGC 7538 is to the upper right.

The Bubble Nebula rises in the northeast late in the evening and is high overhead at dawn.

M17 – The Swan Nebula in Sagittarius

M17 – The Swan Nebula in Sagittarius

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 67x60sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 17.6

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

M17 is a stellar nursery lying about 6,000 light years away along the southern Milky Way in the Sagittarius-Carina arm of our galaxy. The soft red glow of this beautiful emission nebula comes from young stars embedded within the nebula setting the surrounding interstellar hydrogen aglow. M17 is one of the brightest emission nebula is the sky and is visible in small telescopes under dark skies. Even under urban skies the bright inner region of the nebula is a fairly easy target.

M17 is currently well placed in the evening sky rising in the southeast as the sky darkens.

IC 1396A – The Elephant’s Trunk in Cepheus

IC 1396A – The Elephant’s Trunk in Cepheus

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 36x240sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.7

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

IC 1396 includes an open cluster and a vast region of H-alpha emission. If I re-frame this field a little bit farther to the east I can just about capture the width of the nebula. IC 1396A is the sinuous wave that makes up the southern border of a dark nebula called the Elephant’s Trunk. It is neat to take a close look at some of the fascinating detail scattered across this region. I have also had a lot of fun glimpsing the Elephant’s Trunk with my little Revolution Imager 2 video camera where it appears as a faint wisp against the background stars.

IC 1396 is currently well placed in the northeast late in the evening and is high overhead at dawn.

NGC 6888 – The Crescent Nebula in Cygnus

NGC 6888 – The Crescent Nebula in Cygnus

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 19x240sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.7

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

The Crescent Nebula is an emission nebula, usually a cloud of diffuse interstellar hydrogen set aglow by hot young stars born within it. However, in this case the nebula was made by a single, massive, fiercely energetic Wolf-Rayet star at its core. Some 250,000-400,000 years ago this star ejected its outer surface while it was a red giant, forming the expanding shell of the nebula. As the star collapsed it ejected a fast moving solar wind that is pushing against the slower moving gas in the shell forming a shock front giving the nebula its distinctive shape. The Crescent Nebula lies among the rich star fields in Cygnus and almost gets lost in the Milky Way. The five stars forming a “W” across the northern edge of the nebula makes a handy reference for locating this field visually or with a video system.

NGC 6888 is currently well placed in the northeast late in the evening and is high overhead after midnight.

M16 – The Eagle Nebula in Serpens Cauda

M16 – The Eagle Nebula in Serpens Cauda

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 10x120sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.4

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

M16 is actually the cluster in the upper right section of the nebula. The nebula is very subtle and can be difficult to see visually, though it shows well under dark skies. The name, the Eagle Nebula, comes from the dark lanes in the middle which resembles an eagle grasping a fish. These dust lanes are also the famous ‘pillars of creation’ imaged by the Hubble Space Telescope. The nebula is a beautiful expanse of interstellar hydrogen set aglow from young stars embedded within it. M16 lies in the Sagittarius-Carina arm of the Milky Way, the next arm inwards from ours towards the core of our galaxy, so you are looking across the gap between adjacent spiral arms.

M17 is currently well placed in the southeast late in the evening and is high in the south after midnight.

Waxing Gibbous Moon – 10:20pm 6/22/2021 EST

Waxing Gibbous Moon – 10:20pm 6/22/2021 EST

Telescope: ES DHL Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

Exposure: 32x1/1000sec, ISO 1600, saved as RAW

Software: Nebulosity, Registax, Photoshop

Just a quick image of the moon taken last night while I was setting up my gear for an all-night imaging run; hence the narrow-band filter. It’s usually shear insanity to try to do any deep sky imaging with a nearly full moon in the sky and haze drifting through, but narrow-band imaging does a good job cutting through the crud as long as you select suitable targets like emission and planetary nebula. The main target for last night was M17, the Swan Nebula in Serpens Cauda, just a few degrees to the northeast of the moon, and later NGC 7635, the Bubble Nebula in Cassiopeia.

NGC 7000 – North America Nebula in Cygnus

NGC 7000 – North America Nebula in Cygnus

NGC 7000 is part of a vast region of interstellar hydrogen near the plane of the Milky Way just east of the bright star Deneb. Note how the nebula appears to host a rich star field while the dark regions to the left and right appear to be relatively sparse. This shows that the nebula is actually in the background and the dark regions that give the nebula is characteristic shape are lanes of dust in the foreground blocking the light from the distant stars. The northern regions of the nebula include two open clusters; Cr 428 to the upper left and NGC 6996 to the upper right. The nebula to the right is the eastern section of IC 5070, The Pelican Nebula.

The North America Nebula is currently well placed in the northeast late in the evening and is high overhead at dawn.

M8 – Emission Nebula in Sagittarius

M8 – Emission Nebula in Sagittarius

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 44x60sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.4

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

M8, the Lagoon Nebula, is a large bright emission nebula in Sagittarius. It is an easy binocular object and just keeps getting better with larger telescopes. Visually it does look like a lagoon, but photographically it blossoms out into a beautiful red rose. The color comes from diffuse interstellar hydrogen set aglow by stars embedded within it. Note the little globular cluster NGC 6544 to the lower left.

M8 is currently fairly well placed rising in the southeast late in the evening and is above the southern horizon during the early morning hours.

The Veil Nebula Complex in Cygnus

The Veil Nebula Complex in Cygnus

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Radian Triad Ultra Hb, OIII, Ha, SII filter

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

Exposure: 2x(16x240sec), ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 64×1/5sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

The Veil Nebula complex is the remnants of a supernova explosion that occurred between 10,000 and 20,000 years ago. At a distance of 2400 light years, this makes the nebula about 130 light years across. The various regions of the nebula marks the boundary of the shock front from the explosion expanding at a rate of 170 km/sec (106 miles/sec) and now spans a region nearly 3 degrees across in Cygnus. It is comprised of NGC 6992 & 6995 (left), NGC 6979 (upper right), and NGC 6960 (lower right).

The 2 panels of this mosaic were obtained on a single evening as part of a test of using relatively long exposures and narrow-band imaging using the Radian Triad Ultra with the Nikon 610a. The results are encouraging on both counts and bodes well for using this camera over the warm months of summer.

The Veil Nebula is currently well placed rising in the northeast late in the evening and is high overhead as the first blush of dawn tints the morning sky.

Stephenson-1 – Open Cluster in Lyra

Stephenson-1 – Open Cluster in Lyra

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Orion Imaging Skyglow Filter

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

Exposure: 16x60sec, ISO 400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/25sec, tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: Too many clouds to get a good reading

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

This field is centered on Stephenson-1, and open cluster in Lyra near the beautiful yellow star Delta(2) Lyra, located just to the southeast of the brilliant Vega. Delta(2) was born a mere 75 million years ago as a fiercely hot blue star, but it burned through its original hydrogen quickly and is now a swollen red giant with a dead helium core. This star enormous, with a diameter of 242 million miles, 1.3 times the diameter of the Earth’s orbit! It’s beautiful red color is clearly visible through a small telescope and shows well in this image. To the upper right of Delta(2) is the wonderfully blue Delta(1). These two stars share the field with a sparse, triangular shaped open cluster of moderately bright stars called Stephenson-1. This cluster is easy to spot with binoculars and places the Delta(2) and Delta(1) stars in a wonderful field when viewed through a small telescope.

Stephenson-1 is currently well placed rising in the northeast early in the evening.