The Great Globular Cluster in Hercules

Behind the shot

A deep-field capture of the Messier 13 (M13) region within the 'Keystone' asterism of Hercules. The frame resolves the core of the Great Globular Cluster, situated along the western edge of the constellation between the primary stars Eta Herculis (η Her) and Zeta Herculis (ζ Her). Also visible in the wide field are the navigational anchors Pi Herculis (π Her) and the distinct line leading towards Tau Herculis (τ Her) and Sigma Herculis (σ Her).

Observation

Date: 08 Apr 2026
Time: 23:00 - 23:30 CEST
Site: Porto San Giorgio, Marche, Italy
Bortle: Class 6

Bortle Class 6

Bright Suburban Sky
Azimuth: +64° 10' 20.8"
Altitude: +26° 56' 14.8"

Atmospherics

Visibility: Average
Weather: Stable seeing, late night session
Moon: 61% Waning Gibbous - Below horizon

Acquisition

Camera: Panasonic Lumix G7
Lens: LUMIX G VARIO 14-42mm f/3.5-5.6
Mount: Static Tripod (Untracked)
Integration: 100 x 5s

Optics

Focal Length: 42mm
Aperture: f/5.6
ISO: ISO 3200

Post-Processing

Software: SiriL + darktable
Pre-Processing: Master-frame subtraction, FWHM star filtering for cluster hunting, RBF Background extraction.
Post-Processing: Wavelet-based profiled denoise, Local Laplacian contrast, cluster star temperature balancing, black level fine-tuning.