Tools
Deep Sky Annotator
The M102 Astro Annotator uses WCS plate solving to automatically identify and label deep sky objects, stars, clusters, and nebulae in astrophotography images. It queries the SIMBAD astronomical database to retrieve object classifications, distances, and spectral types.
Every annotated image on this site was created with this tool.
WCS Plate Solving
Maps pixel coordinates to celestial coordinates (RA/Dec) using your image's FITS header data.
SIMBAD Integration
Queries the Strasbourg astronomical database for object types, distances, and spectral classifications.
Smart Labeling
Prioritizes labels by object significance with intelligent collision avoidance for clean overlays.
Scale Bar
Adds a physical light-year scale bar based on the median distance of visible objects.
Export Ready
Renders high-resolution annotated images for social media, prints, and educational content.
Session Save/Load
Save annotation sessions as JSON — adjust labels, visibility, colors, and styling anytime.
Try the Web Annotator
Upload your plate-solved astrophotography images and get instant deep sky annotations — no software installation required. Paste your FITS header, query SIMBAD, and export annotated images directly from your browser.