downloads
This section is intended to host my personal coding projects. These are provided for free and as they are for anyone that might find them useful. The codes are well commented but I cannot guarantee support. All source code is subject to the Academic Free License as published here, and provided on an 'as is' basis, i.e. without any warranty.
If you wish to use my codes or animations, I would appreciate it if I get a mention as the original author. Furthermore, if you find them useful, drop me a line to say so! It is always pleasant to receive encouraging feedback.
python projects
Astronomical Utilities – This is a set of python
modules that provide basic tools for research astronomers. It can be
used to convert between different coordinate formats and calculate rise
and set times for various astronomical objects. See the README file for a
description of the routines.
Download astro_util.
animations
Point-source, point-lens: Lensing occurs when the path of light from a distant luminous source (shown as a filled blue circle) travels near a massive object (shown as a black circle), called a "lens", and gets bent due to the gravity of the lens. The images of the source generated by the lensing effect are shown as green. The lightcurve showing the change in magnification, being the sum of the areas of the two images divided by the area of the unlensed source, is displayed on the right. Download this movie here.
Point-source, binary-lens: When the lens is composed of two massive objects, the images of the source generated by the lensing effect are no longer two, but either three of five (shown here as green spots), depending on the location of the source (blue circle) relative to the caustics (blue cuspy curves). When the source crosses a caustic two new images get created or destroyed. The lightcurve generated by this particular arrangement is shown on the right. Download this movie here.
Point-source, binary-lens - different mass ratios: The shape of the caustics is very sensitive to the mass ratio between the two components of the lens. Components with different mass ratios produce different caustic structures, as illustrated in this animation. The source trajectory is represented by the solid black line. The resulting lightcurve (shown on the right) is quite sensitive to the mass ratio. Download this movie here.
Point-source, binary-lens - different component separation: The shape of the caustics is also sensitive to the separation between the two components of the lens. Larger separations stretch the caustics along the binary axis, while beyond a certain point the caustics split up. The source trajectory is represented by the solid black line. The resulting lightcurve on the right shows how the component separation influences the final shape. Download this movie here.