Sidereal: Deep Sky Atlas

iOS app by Shadowfetch · App Store ID 6792598858 · iOS

Sidereal is a serious, offline sky atlas and observation planner built for amateur astronomers and astrophotographers — not another horoscope or AR toy. Every star position, rise time, and planetary coordinate is computed on your device from bundled professional catalogs, so it works perfectly at a dark site with no cell signal.

A Real Catalog In Your Pocket

328,000 stars down to magnitude 10 (Hipparcos / ATHYG), with proper names, Bayer and Flamsteed designations, spectral types, distances and luminosities
13,000+ deep-sky objects — the complete NGC and IC catalogs
The full Messier catalog and the Caldwell catalog, curated for observers
Constellation stick figures, IAU boundaries and full constellation reference
Everything is bundled and offline — no account, no cloud, no tracking

Interactive Sky Chart

Pan and pinch a live planetarium view of the sky from your exact location and time
Stars sized by magnitude and tinted by colour index; deep-sky objects drawn by type
Constellation lines and labels, the ecliptic, an alt-azimuth grid and a true horizon with cardinal points
Planets, the Sun and the Moon plotted from real ephemerides
Tap anything to identify it and open a full data sheet
Scrub time forward or back to see how the sky moves

Precise Positional Astronomy

Rise, transit and set times, plus an altitude curve for any object across the night
Astronomical, nautical and civil twilight, and hours of true darkness
Precession, nutation, sidereal time and apparent (of-date) coordinates
Planetary and solar positions from the VSOP87 theory; lunar position, phase and illumination from an ELP-2000 series — all evaluated on device

Plan Your Night

Tonight view: sunset to sunrise, moon phase and interference, planet visibility
The best Messier and Caldwell targets tonight, ranked by altitude during darkness and distance from the Moon
Observing lists you build yourself, and a session log for seeing, transparency, equipment and notes

Get it. Sidereal: Deep Sky Atlas is on the App Store for iPhone and iPad.

Privacy and support

Privacy information for Sidereal: Deep Sky Atlas · Support for Sidereal: Deep Sky Atlas

Questions: shadowfetchapps@gmail.com

Sidereal: Deep Sky Atlas · App Store ID 6792598858 · Published by Shadowfetch · shadowfetch.com