Archives for December 2021

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 37x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky 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 last image in a very long series of 42 images taken to explore basic deepsky imaging using fairly simple equipment including a stock and a modified DSLR and several different 8” SCTs operating at f/10 and f/6.3, all on various altaz mounts (LX90, LX65, and Light Switch), and just an interval timer, no computer, no guiding. This has been a really fun journey and one that I’ll likely pick up again in the spring. It has also proven to be very helpful reminding me just how much you can do with relatively gear and it offers a nice option for a variety of different bright targets and projects such as monitoring asteroids and variable stars.

So much to try, so few clear nights…

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 40x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.4

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky Stacker, Nebulosity, Photoshop

Located less than 5 degrees from the north celestial pole NGC 188 is one of the most northern objects in the New General Catalog. It is also one of the oldest open clusters known with an estimated age on the order of 5 billion years. Open clusters usually slowly disperse as they interact with other stars in the surrounding galaxy. NGC 188, however, lies above the galactic plane where it is fairly isolated. Composed almost entirely of 12 and 13^th magnitude yellow giants, I find this cluster to be quite delicate, requiring very good transparency to be visible in an 8” telescope. Under these conditions it blossoms into a rich field of tiny pinpoints of light on the edge of visibility and it is quite beautiful. In a larger telescope it becomes easier to see, but remains quite faint and subtle.

NGC 188 is currently well placed above Polaris in the evening sky.

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 40x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.5

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky Stacker, Nebulosity, Photoshop

NGC 7789 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.

NGC 7789 is currently high in the northeast after sunset.

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 22x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.5

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky Stacker, Nebulosity, Photoshop

M52 is a relatively bright open cluster just to the west of Cassiopeia. Visually, M52 appears as a fine patch of stardust in small telescopes while larger telescopes show a broad expanse of fainter stars. The faint, rich field to the right of M52 is the open cluster Czernik 43.

M52 is currently high in the northeast after sunset. 

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 39x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky Stacker, Nebulosity, Photoshop

NGC 457 is one of my favorite open clusters in just about any size telescope. It makes a fine target for binoculars and small telescopes and becomes a very rich field in larger scopes. The two bright distinctive foreground stars makes it fairly easy to locate. In a small telescope it is worth taking some time with this field. At first your eye may only see the two bright foreground stars and a few of the brighter stars of the cluster. As your eyes relax you may start to see some of the fainter background stars and the cluster will begin to blossom into a beautiful field of stardust.

NGC457 is currently well placed high in the northeast after sunset.

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 38x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.6

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky 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.

M2 is currently in high the southwest at sunset.