astronomy

selected field notes

Unless otherwise noted, all observations were made from my backyard (Bortle 7) using an 8-inch Dobsonian (Apertura AD8).

February 17, 2024 – First Light / Jupiter

Collimated the AD8 using the included laser collimator. Process was straightforward on the first attempt; future collimation should be quick. Thumb screws from the Apertura upgrade kit significantly simplified adjustment.

Seeing rated mediocre by Astrospheric; transparency good. Scope set out early for thermal equilibrium.

Moon observed first: strong contrast at 30 mm; excellent crater detail at 9 mm.

Jupiter observed with all four Galilean moons visible. Planetary disk bright with faint banding.

RACI finder alignment refined using the Moon; once calibrated, target acquisition was easy even at higher magnification and low altitude near obstructions and light pollution.

April 22, 2024 – M44 (Beehive Cluster)

Open cluster clearly resolved despite Bortle 7 conditions.

June 1, 2024 – M3 & M53 (Globular Clusters)

Most distant objects observed to date. Visibility confirmed that globular clusters are achievable targets even under heavy light pollution.

December 13, 2024 – Jupiter & Mars

Observed at ~4–8 mm focal lengths. Jupiter showed two prominent orange bands, two lighter bands, and all four moons. Mars appeared large and well-defined.

June 11, 2025 – M13 (Hercules Cluster)

Observed through the 24-inch research reflector at Loines Observatory, Nantucket, MA. Dramatically higher resolution than an 8-inch Dob: extensive stellar resolution resembling a shimmering web rather than a diffuse glow.

Also observed Mars through the observatory’s historic 8-inch Alvan Clark refractor (19th century).

August 30, 2025 – M57 (Ring Nebula)

Planetary nebula easily located near Vega. Initially mistaken for defocus until surrounding stars confirmed sharp focus. Distinct annular shape visible.