Astro Observation Log

Astro Observation Log is a simple, offline logbook for amateur astronomers. No account, no sign-up — every session stays on your device.

Key features
• Log each session: target, date, equipment, location/sky conditions, and detailed notes.
• Messier tracker: mark which of the 110 Messier objects you have observed and watch your progress grow.
• History: browse past sessions and revisit what you saw.
• Search your log by target or equipment.
• Red-light night mode to protect your dark adaptation at the eyepiece.

Privacy
All data is stored locally on your device and is never uploaded to our servers. The app does not require an account or location permission.

Whether you observe from a backyard or a dark site, keep a clean record of every night under the stars and complete your Messier list.