Star Charts by Wil Tirion app for iPhone and iPad

These are serious Star Charts! Not a planetarium-type app suitable for beginners, but rather a very detailed series of charts of the night sky for observers using binoculars or a telescope. Prepared by famous celestial cartographer Wil Tirion, they present the entire sky in the form of 18 charts, 16 covering the equatorial region of the sky (8 each side of the celestial equator) and one for each of the Polar Regions.

Features include:
* Stars down to sixth magnitude; double and variable stars included.
* All Messier objects, plus many NGC and IC catalogue objects.
* Auto detection of your location and presentation of the chart containing the sky directly overhead.
* Choice of positive charts (white on black, recommended to preserve night vision) or negative (black on white – easier to read and better for daytime use.)
* Charts can shown north up or south up to match your location.
* Search charts by constellation or major star name.

Basic default maps show constellation names, constellation lines and major star names only.
Extra layers can be added to reveal:
* Constellations boundaries for all 88 constellations.
* Grid lines and co-ordinates for every hour of Right Ascension and 10º of Declination.
* Star numbers and deep sky object names.