Halley - Electronic Ephemeris of Comets

Halley is a free software for managing and working with the regularly updated database of comets, containing Keplerian orbital elements, non-gravitational and physical parameters of the comets and other data. The tasks performed by Halley software, in addition to database management, include calculation of the orbital evolution of small-bodies and visualization of their dynamics, detection of close approaches with the major planets in a given time interval, as well as a number of other tasks.

Main features

• The regularly updated database of comets.
• Database management with the ability to add your own objects.
• Quick search on any database element.
• Import/Export from ECS Format.
• High-precision and high-speed calculation of small-bodies orbits.
• Visualization of small-bodies orbits.
• Calculation of orbital evolution of small-bodies.
• Calculation of moments of perihelion passages.
• Detection of close approaches with planets.

How Halley works?

The core of Halley software has been implemented in Fortran. This allows to produce high-precision integration of the equations of motion of asteroids and comets. The gravitational perturbations from all major planets and Pluto are taken into account in the equations of motion. Coordinates of the perturbing planets are computed on a basis of JPL Planetary and Lunar Ephemerides. Equations of motion include relativistic perturbations from the Sun. Perturbations of the Earth and Moon are taken into account separately. Marsden's model was taken as a model of non-gravitational accelerations with perihelion-maximum offset parameter. Numerical integration of the equations of motion is performed by Everhart's method of 11-th order with automatic control of step size. High accuracy of numerical integration is achieved through the use of the modified Encke's method. The modification consists of performing the change of the osculation epoch at each step of integration. The parameters of the unperturbed motion are calculated with quadruple precision by using variables with 32 decimals. Database management is performed using the SQLite library.

Screenshots

System Requirements

• Microsoft Windows® XP/Vista/7/10.
• 256 MB of memory or greater.
• Approximately 300 MB of free disk space.

Download Halley

Halley - Electronic Ephemeris of Comets v.0.06 (Size: 3.5 MB)

Halley Manual

Any Questions?

If you have any questions, please check the Halley Manual first. Any suggestions, comments, testimonials or bug reports are welcome. If you have found a bug, please report it. Please, write down the version of Halley, a description of the problem, and how to reproduce it. Also, please include a brief description of your system (CPU type and speed, RAM size, version of Windows). Your feedback is very important because it helps to make a better product for you. A lot of features and significant details in the Halley interface were considerably influenced by users comments. So if you have any ideas about new features or if you know a better way how to do something, please share it with me. I will be grateful for any help you can provide.

Yury S. Bondarenko, bondarenko@iaaras.ru