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.