Astrophotography Planner

Astrophotography Planner is a deep-sky imaging assistant built for amateur astronomers and astrophotographers. Plan your nights, frame your targets, and log your sessions — all in one offline-first app.

— TONIGHT AT A GLANCE —
Pick your observing site once. The app then shows you every number that matters for tonight: sunset, civil/nautical/astronomical twilight, dawn times, the dark window in hours, moon illumination percentage and phase, Milky Way core peak altitude, and a 24-hour weather forecast (cloud cover, wind, humidity, precipitation) with an imaging-quality score for every hour.

— DEEP-SKY CATALOG —
135 hand-curated objects: 110 Messier galaxies, nebulae, and clusters plus 25 popular NGC/IC targets. Every entry includes magnitude, apparent size in arcminutes, host constellation, best months, right ascension, declination, and a live altitude/azimuth for your selected site. Filter by object type (galaxy, emission/reflection/planetary nebula, supernova remnant, globular/open cluster, double star) and tap any target to see if it's well placed right now.

— FIELD-OF-VIEW SIMULATOR —
Add your imaging trains (scope + camera) once with focal length, aperture, sensor dimensions, pixel pitch, and mount payload. The simulator draws your sensor frame around any catalog target so you can see at a glance whether it fits, overflows, or wastes the field. Image scale in arcsec/pixel is computed automatically.

— EXPOSURE & INTEGRATION CALCULATORS —
The Exposure Calculator computes the recommended sub-exposure length for sky-noise-dominated stacks given your sky brightness (SQM), camera read noise, and chosen sky-noise multiplier. The Integration Calculator tells you how many more subs you need to hit a target SNR based on what you already have.

— POLAR-ALIGN DRIFT TOOL —
Plug in a measured declination drift (arcseconds over minutes) and the tool returns your residual polar-alignment error in arcminutes, with a quality rating from "Excellent" to "Refine alignment".

— MOUNT PAYLOAD CHECK —
Sum the weight of your imaging train and compare against your mount's stated payload capacity. The 80% threshold warning prevents tracking degradation before you've spent the night fighting elongated stars.

— PRE-SESSION CHECKLIST —
14 pre-built items covering power, balance, polar alignment, focus, dew protection, cooler ramping, dust checks, plate-solve verification, calibration libraries, red-mode lighting, and supplies. State persists between sessions.

— MOON CALENDAR —
Month grid with each day color-coded by moon illumination percentage. Tap any date to see twilight times for that night. New-moon weeks (lowest illumination) are surfaced for deep-sky planning.

— SESSION LOG —
Log imaging sessions with date, site, target, weather, seeing in arcseconds FWHM, transparency rating, and free-text notes. For each session, log light, dark, flat, and bias frames with exposure, count, and ISO/gain. Total integration time is computed automatically.

— PRIVACY-FIRST, OFFLINE-FIRST —
All sites, gear, sessions, frames, and checklist state are stored locally on your device. There is no cloud sync, no account, no remote database. Internet is used only for ads (free tier), purchase verification, and optional weather forecasts from the public Open-Meteo API.

— FREE & PRO —
The free tier includes one observing site, two gear setups, five session logs, and the first 60 catalog objects, with ads. Pro Lifetime is a one-time in-app purchase that unlocks unlimited sites, unlimited gear, unlimited sessions, the full 135-object catalog, and removes ads. Pricing shown in-app at purchase.

— SUPPORT —
Email: dev@corithmflowmatrix.com
Privacy policy and terms of service available in Settings.

Recent changes:
Ads governance framework v1: improved ad policy compliance and traffic quality.