Astro Transit vs AstroTool

Astro Transit is a simple application for calculating meridian transit times, transit altitude, and target visibility for astronomical objects from any observing location. Targets are resolved automatically using the SIMBAD astronomical database operated by the Centre de Données astronomiques de Strasbourg (CDS), France, or entered manually using coordinates (useful for newly discovered transients, novae, etc.). The application also provides sunset, nautical twilight, sunrise, and moon illumination information for the selected date. A multi-target interactive visibility curve feature shows how a target’s altitude changes through the night, helping observers visualise the best time to observe consecutive targets. Astro Transit is designed as a quick planning aid for advanced amateur and professional astronomical observation.

AstroTool — Astrophotography Planner & Sky Map Plan better. Shoot more. Miss nothing. AstroTool is the complete astrophotography companion for iPhone — from scouting tonight's targets to logging every capture. A live sky map you can actually use in the field, planning tools built around how astrophotographers think, and a session logger that keeps your imaging history in one place. FREE FEATURES Sky Map A fully rendered live sky chart with 100+ bright stars, all 110 Messier objects, the Sun, Moon, and all planets. Constellation lines, constellation name labels, the Milky Way band, and the ecliptic arc are all drawn in real time. Tap any object for instant identification — name, type, magnitude, and position. Procedural rolling-hill horizon with compass ticks and cardinal labels. Motion-driven so the sky moves as you move. Deep Sky Catalog Browse the complete Messier catalog with search, type filters, and sort by ID, magnitude, or altitude. Every object shows rise, transit, and set times for your location, a visibility chart for tonight, and your full capture history for that target. Mark favorites and pick up right where you left off. PREMIUM — ONE-TIME UNLOCK Planner Everything you need before you head out. Moon phase and illumination with an imaging impact rating. Full twilight schedule — civil, nautical, and astronomical dusk and dawn with total dark-sky hours. All visible planets with live altitude and transit times. Jupiter's Galilean moons in a live canvas diagram. Best targets tonight ranked by a composite altitude and moon-separation score. Target schedule to plan your imaging windows object by object. Astrophotography Calculator Field of view for your exact sensor and focal length with sensor presets for Full Frame, APS-C, Micro 4/3, and custom. Unguided exposure limits via the 500, 400, and 300 rules for fixed tripod, tracking mount, and guided setups. Integration time calculator with sub count and a signal quality indicator. Session Logger Log every observing session with sky conditions — Bortle scale, seeing, and transparency. Add individual captures with exposure length, sub count, gain, filter, equipment, reference path, and a star rating. Total integration time tracked automatically. Export any session as formatted text to share or archive. Full equipment manager for telescopes and cameras with sensor specs, focal length, and reducer support. Target Schedule Build a nightly imaging plan by scheduling capture windows for specific catalog objects. Log past captures directly from the schedule. Mark targets done as you work through the night. Events & Alerts Upcoming meteor showers with ZHR and peak dates, lunar phases, planet oppositions and conjunctions, greatest elongations, and solstices and equinoxes. Notification support so you never miss an event. Polar Alignment Guide & Pre-Session Checklist Step-by-step polar alignment instructions and a fully customisable pre-session checklist with presets covering setup, camera, focusing, guiding, imaging, calibration, and wrap-up. — No subscription. No ads. No account required. Pay once, own everything forever. All calculations run on-device using your GPS location. No data is sent anywhere.