November 21, 2024

Archives for May 2024

Waxing Gibbous Moon – 5/19/2024 21h 22m EDT

Telescope: Astro-Tech RC8 @ f/8, Orion Atlas EQ-G

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

Exposure: 50×1/640 sec, ISO 800, saved as RAW

Seeing: Fair, 3/5

Software: Backyard EOS, Nebulosity, Autostakkert, Registax, Photoshop

Just a quick peek at the moon between targets on a warm spring evening.

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.