A native Android planetarium for the observer with a manual mount and no GoTo. It computes where every object is right now — and then, with push-to guidance, tells you exactly how far to turn and tilt your scope to land on it. The sky math is validated against astropy to within 0.7°, not asserted.
Astrum is part of an astronomy pillar — Astrum (point) · Skytime (plan when/where to go) · PhotoSharp (process the capture) — over one shared, validated ephemeris engine.
- Push-to (the "Localizar" tab). Hold the phone against the tube; Astrum reads the device orientation, projects it to alt/az, and guides you — turn 12° right, tilt 8° up — onto the target. The math that GoTo mounts do in hardware, on a manual 114EQ.
- Where things are, now. Real-time altitude/azimuth, rise/set and transit for any object,
from local sidereal time and your GPS position (
AstroEngine). - Sun & Moon. Position, phase, illumination, and the full twilight ladder — civil,
nautical, astronomical dawn/dusk (
SolarCalc,LunarCalc). - Planets. Orbital-mechanics positions for the seven major planets (
PlanetCalc). - Catalog. The 110 Messier objects + 35 brightest stars, searchable and filterable, each with live altitude and a visibility readout.
- Made for the dark. A night mode (deep red on black) preserves your dark adaptation at the eyepiece; custom canvas views render a twinkling star field and the Moon's current phase.
The ephemeris is cross-checked against reference implementations — every claim maps to a check in
validation/ (run with Python):
| Check | Result |
|---|---|
validate_astroengine.py — alt/az vs astropy |
max error 0.73° (tolerance 1.0°) ✓ |
validate_pointing.py — device-orientation → alt/az projection |
all cases ✓ |
validate_pushto.py — turn / tilt / angular-separation math |
all cases ✓ |
So the push-to guidance rests on math that has been checked against the gold standard, to better than a degree — comfortably inside an eyepiece's true field of view.
- Android 8.0+ (API 26), Android Studio, Kotlin.
- Open the project, connect a phone, Run. Grant location (for your sky) the first time.
Kotlin · Android Canvas API + Fragments · FusedLocationProviderClient with Kotlin Flow ·
dedicated calculation modules (astro/) with a Python validation harness.
MIT © QuantumDrizzy — see LICENSE.