Archives for December 6, 2020

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

Camera: ZWO ASI071MC Pro, -10C, Gain 200, Baader Mk III MPCC

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD

Exposure: (12+16+36+44)x240s, saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32×0.2s, sky flats taken at dusk

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

Lensed Sky Quality Meter: 18.0-18.4 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

M97 is a wonderful little planetary located just below the bowl of the Big Dipper. It is easy to locate, but a challenge to see from my light polluted backyard. I chose this as the last target from a series of all-night imaging runs starting on the evenings of November 6, 7, 9, and 11. The sky conditions on each of these nights were relatively poor and the source images were pretty rough, but combining a total of 119 images gave a pretty nice result.  If you look closely there are tiny galaxies scattered across the field. For example, to the lower left of the nebula is PGC 34279 (Mv 16.0) and above the nebula are PGC 2490291 (Mv 17.6) and 2490640 (Mv 17.3).

M81 – Spiral Galaxy in Ursa Major – Asro-Tech RC8, ASI294MC Pro

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

Camera: ZWO ASI294MC Pro, 0C, Gain 200

Filter: 2” Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD

Exposure: 52x240sec, saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32×0.25sec, sky flats taken at dusk

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

Lensed Sky Quality Meter: 17.9 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

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 tinged with blue star forming regions resulting from a close encounter with M82.

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

Camera: ZWO ASI071MC Pro, 0C, Gain 200, Baader Mk III MPCC

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD

Exposure: 95x90s, saved as FITS

Darks: 32x90s, saved as FITS

Flats: 32×0.2s, sky flats taken at dusk

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

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

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

This is one of several first-light images taken with my shiny new ASI071MC Pro. The 071 uses an APS-c size chip which makes good use of the relatively flat field of the RC8. It’s neat to compare this camera with the D5300a that I have been using for much of the past year.

M42 is the large section of this nebula while M43 is the smaller, comma shaped section above M42. The red regions of the nebula is light from interstellar hydrogen set aglow by newly formed stars, the smoky blue/gray is starlight reflecting off of interstellar dust, and the dark lanes are veils of dust in the foreground. In this particular image I love the fine detail in the smoky gray rift between M42 and M43.

Visually, M42 appears as a delicate puff of gray smoke about midway along the length of a string of stars that form the Sword of Orion. This line of stars point southwards from the three bright stars that form the distinctive Belt of Orion that is rising in the east as twilight deepens this time of year. The Sword and M42 are easily visible in binoculars or a small telescope. Under dark skies The Great Nebula can even be seen without any optical aid. In a modest telescope the nebula shows some wonderful fine structure in its triangular core that often gets lost in processed images like this one. The core hosts a tiny group of 4 young, relatively bright stars called the Trapezium.

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

Camera: ZWO ASI071MC Pro, -10C; Gain: 200

Filter: 2” Orion Imaging Skyglow filter

Guide scope: Williams Optics 50mm, Meade DSI Pro II, PHD

Exposure: 16x240sec saved as FITS

Darks: 32x240sec saved as FITS

Flats: 32x10sec using an LED tracing tablet with 3 layers of muslin

Average Light Pollution: Red zone, fair transparency

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

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, 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. If you look to the left of M81 you can just barely glimpse the irregular galaxy UGC 5336. This little ghost is approximately 13 million light years away and is only about 9200 light years across.

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

Camera: ZWO ASI294MC Pro, 0C, Gain 200

Filter: 2” Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD

Exposure: 57x240sec, saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32×0.25sec, sky flats taken at dusk

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

Lensed Sky Quality Meter: 17.6 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

M82 is a close company to the nearby spiral galaxy M81 which is located about ½ degree to the south. These two form an interacting pair and M82 bears the scars of a close encounter with M82 about 100 million years ago. The dark dust lanes that cut across the central region of the galaxy are very distinctive and are easily visible in modest telescopes. M82 was originally classified as an irregular galaxy, but detailed studies had shown that it is actually a spiral seen nearly edge-on.