AstroAid vs Open Planetarium

AstroAid is an app for amateur astronomers that functions as an aid to visualizing what you will see through your telescope/camera lens when you use a particular eyepiece and, optionally, an optical aid (such as a Barlow lens). You can also pair a camera/imager with a telescope and determine what your camera/imager will see in its frame. This will be a big help for astro-imagers. The app computes a number of parameters for your telescope/eyepiece/imager combination, such as magnification, actual field of view, visual magnitude limit, etc. and displays these values in tabular form. Several astronomical catalogues are built in to the app (including Messier, NGC, IC, and many other object catalogues), and will be updated on-line occasionally. Images for these objects can be downloaded. All catalogues can be searched. The app contains extensive lists of known vendor-supplied telescopes, camera lenses, eyepieces, imagers, and optical aids. You can also create your own custom entries if your equipment isn't listed (for example, if you made your own telescope). These custom entries are shared between your devices via iCloud (if available).

Open Planetarium is a beautiful, scientifically accurate virtual planetarium. The full sky works completely offline — all star, constellation, and deep-sky data is bundled with the app. FEATURES • Real star catalog: 8,920 stars down to magnitude 6.5 (HYG v4.1), with scientifically accurate star colors derived from each star's B-V color index • All 88 constellations: lines, names (English / Japanese / Latin), and official IAU boundaries • Solar system: the Sun, the Moon with phases and lunar age, and all 7 planets, computed with Meeus/Standish-compliant algorithms • Deep-sky objects: the complete Messier catalog (110 objects) plus major NGC/IC objects — 717 objects in total, with type icons • Powerful search: object names, constellations, M/NGC/IC numbers, planets • Object details: magnitude, coordinates, altitude/azimuth, and rise/transit/set times for your location • Time travel: set any date and time with the calendar dialog, scrub through the day with the time slider, or play diurnal motion at 60×/600×/3600× • Observing location: pick your spot on a zoomable world map with 1,250+ cities, search by country/city, enter coordinates manually, or use GPS • Survey imagery: overlay DSS2 sky survey layers (downloaded on demand and cached for offline re-display) • Equipment & field-of-view simulator: register telescopes, cameras, eyepieces and Barlows/reducers to preview framing and plan mosaic imaging • Milky Way rendering and adjustable light-pollution levels PRIVACY Your location is used only on your device to compute the sky above you — it is never sent anywhere. If location permission is denied, you can set the observing location manually. Open Planetarium is free, open source (MIT), with no ads and no tracking.