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AstroGrav 4.3 Released for Windows and Mac

AstroGrav adds many new features and improvements to its precision solar system simulator

23rd January 2021 - AstroGrav 4.3 includes major improvements to ephemeris generation, including an option to include the effects of refraction in calculations. There are several improvements to the handling of dates and times in solar system simulations, more options for drawing trajectories and histories, and a greatly improved precession model for the Earth. Full details are available from:

Ephemeris Generation

When generating an ephemeris, there is a new option that allows refraction to be taken into account when calculating the apparent position of an object. The data displayed in an ephemeris window is now immediately updated whenever the viewpoint is changed or the 'Planetary Aberration', 'Refraction', or 'Use JNow' settings are changed. An ephemeris can now be duplicated, so that by duplicating an ephemeris and then changing the viewing location of the duplicate, it is easy to see side-by-side ephemerides of the same object from two different locations. Another improvement is that after reopening a simulation with ephemeris windows, the reopened windows now appear exactly the same as when they were saved, instead of being cleared as in earlier versions.

Other Improvements

Dates and times in solar system simulations can now be displayed and entered with milliseconds, date entry has been made more flexible, and the Proleptic Gregorian Calendar is now used throughout. Further options have been added when drawing trajectories and histories, including the ability to have different sized trajectories in different windows of the same simulation. View windows include several improvements, including more accurate planetary aberration calculations, and the addition of redshift and blueshift effects when viewing from an object that is moving at a very high velocity. A greatly improved precession model has been added, which provides accurate precession for 200,000 years either side of the present time - something that will be useful to those wishing to use AstroGrav for archaeo-astronomical purposes. The sample simulations have been updated to now use Barycentric Dynamical Time (TDB) by default, instead of Coordinated Universal Time (UTC), and many other minor improvements and bug fixes complete this major upgrade.


The AstroGrav 4.3 update is free of charge to all AstroGrav 4 license holders. They may download and install the update immediately from:

About AstroGrav Astronomy Software

AstroGrav Astronomy Software produces astronomical and gravity simulation software for astronomers, researchers, educationalists, and students. For more information, visit the company's website:

Press Contact:
Russell Calvert
AstroGrav Astronomy Software