Astronomcupu

Software · Desktop · macOS & Windows

Will the crescent
be visible tonight?

Hilal Ephemeris computes the Moon's altitude and elongation at sunset across the entire planet, then draws the MABIMS and KHGT criteria right onto the map. Precise positions, straight from NASA JPL.

Download
  • v0.0.4
  • GPL-3.0
  • JPL DE440s
Hilal Ephemeris main window showing the MABIMS visibility map of Indonesia for 28 February 2025

Everything for a hilal observation,
in one window

01

Visibility maps

Moon altitude and elongation at sunset, gridded across Indonesia or the whole world. Hover to read values, click any point for the full breakdown.

02

MABIMS & KHGT criteria

Criterion lines and shaded regions drawn straight onto the map. Toggle MABIMS (geocentric or topocentric) and KHGT as layers, with legends included.

03

Sky simulation

Animate the Moon, Sun and planets in a chosen field of view around sunset, then export it as a GIF.

04

Moon–Sun offsets

Plot the azimuth and altitude difference between Moon and Sun for every saved location, against the criterion lines.

05

Choose your kernel

Switch between JPL ephemerides (DE430 through DE442) from inside the app, with year ranges and sizes listed. Out-of-range dates are refused clearly.

06

Locations built in

All 38 provincial capitals ship with BIG coordinates. Edit them or add your own; checked locations are computed with every map and saved to CSV.

Sky simulation

Watch the sky at sunset, minute by minute

Pick a location and a time span. The app animates the Moon, Sun and planets around the setting Sun, with elongation, altitude and illumination in the corner of every frame. Save the result as a GIF for a report or a talk.

Sky simulation of the Moon, Sun and planets over Jakarta at sunset

More views

World crescent visibility map for 28 February 2025 with MABIMS criteriaIndonesia crescent visibility map for 28 February 2025 with MABIMS criteriaMoon versus Sun azimuth and altitude difference plotAltitude and elongation over time at one locationSun and Moon position panel for one location

Precise by construction

Sun and Moon positions come from Skyfield reading JPL Development Ephemerides published by NAIF. Boundaries use Natural Earth. Apparent topocentric coordinates, with optional dip correction from elevation. Every result is saved as a reusable grid, so re-plotting is instant.

Download Hilal Ephemeris

Version 0.0.4, released 6 October 2026. Free to download.

  • macOSApple Silicon · macOS 11 or laterSHA-256 b12bdd2064237738a9cf7125381e0e98cb2f016403b84d8d02e2540f92fc8688
    Download · 159 MB
  • Windows64-bit · installs without administrator rightsSHA-256 7d30af6012853b8532e4807e5e07fc73507375f371a68baa0df4498c4608af3d
    Download · 117 MB
First launch on macOS

The app is not notarised by Apple, so macOS may say it cannot verify the developer. Unzip it, then right-click app_ephemeris and choose Open, and confirm. You only need to do this once. Or, in Terminal:

xattr -dr com.apple.quarantine app_ephemeris.app

To check the download, compare its SHA-256 with the value above:shasum -a 256 Ephemeris-0.0.4-macos-arm64.zip

First launch on Windows

The installer is not code-signed, so Windows SmartScreen may show “Windows protected your PC”. Choose More info, then Run anyway. The installer does not need administrator rights. To check the download, compare its SHA-256 with the value above:Get-FileHash Ephemeris-Setup-0.0.4.exe