Archives for May 2022

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 34x120sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

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

Average Light Pollution: 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, Deepsky Stacker, Nebulosity, Photoshop

M56 is a relatively small, dense globular cluster that tends to get a bit lost against the background Milky Way. I have always found this to be a somewhat challenging object visually (at least from my backyard) but it blossoms beautifully with a camera.

M56 currently rises in the northeast as the sky darkens.

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 23x120sec, 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, low altitude

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

M20, the Trifid Nebula in Sagittarius is one of a series of nebula that grace the summer Milky Way. The red is a tenuous cloud of interstellar hydrogen set aglow by stars embedded in it, the blue is dust in the background reflecting starlight, and the dark lanes are vast streamers of dust in the foreground. Being near the Milky Way this field is crowded with faint stars, though the density of stars is uneven. The dark regions show areas of dust blocking the light from the faint distant stars in the background while the brighter regions are relatively clear avenues into the deep galaxy beyond.

M20 is currently a morning object, rising late in the evening and over the southern horizon near dawn.

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 17x180sec, 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: 18.5 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

NGC 5907, the Splinter Galaxy, is very slender edge-on spiral galaxy with a small central bulge and a pronounced dust lane. The dust lane shows some wonderful detail and gives the core a beautiful amber color. The galaxy itself is something of a giant lying 59 million light years away and 180,000 light years across.

NGC 5907 is currently well placed high in the overhead during the early evening.

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 10x240sec, 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: 18.5 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

This field needs more subs and better conditions, but since I am limited to imaging on the east side of the meridian that will have to wait until next year.

M51 is a beautiful face-on spiral galaxy in Canes Venatici, just south of Alkaid, the bright star that lies at the eastern end of the Big Dipper. 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 currently well placed high in the northeast during the early evening.

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 28x120sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/80s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, 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: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

Like many globular clusters M5 is a relic of the early universe with an estimated age of 13 billion years. It is also one of the largest known globular clusters home to as many as 500,000 stars in a region 165 light years across. Its large size has been a major factor in its longevity. Globulars near the galactic plane slowly disperse as they lose stars to the Milky Way. However, M5 is so large that it has been able to hold on to most of its stars. At magnitude 5.7 M5 is an excellent target for small telescopes.

M5 currently rises in the east during the early evening and is visible for most of the nigth.

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 28x120sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/80s tee shirt 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

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. The larger apparent size of M13 likely contributes to its slightly higher total integrated brightness.

M92 currently rises in the northeast during the early evening.