Last updated 2009 June 25
This page includes software that may be of use in the observation of asteroids both in locating them and analyzing the CCD images obtained. Please note that the comments are more likely to reflect my understanding and/or usage of the various applications rather than list all their features. For a fuller picture please visit the relevant websites.
A multitude of astronomical software packages are listed here.
My thanks to; Alan Cahill,
1.0 Star charts
I have used Megastar for a number of years now and have always been quite happy with it. When first used for visual observing it was always a simple task to match orientation, field of view and magnitude with what I was seeing through the eyepiece. The same is now true for CCD imaging. Asteroid elements are simple to enter and tracks equally simple to produce. Now that access to USNO catalogues is incorporated it meets all my needs.
‘Guide is a real workhorse and it is the one I would recommend to a beginner. It will plot your MPC format observations onscreen so you can reject outliers, it will plot objects on the NEOCP confirmation page (or NEODys or JPL etc) onscreen. One big advantage is that it can be used as a 'digital finder'. Even if your target is way outside your frame you can see on the screen and manually slew to it. Very helpful! You can click on an object and have Charon automatically load the object and analyse the image and a click writes the MPC email. It will also place a red cross over the target-very helpful.Orientation of image is not important
Excellent after sales service from Bill , a very gifted celestial mechanic. Can use any catalogue. I personally prefer Guide 7 to Guide 8- I currently use Guide/Charon as the 'finder' and backup if Astrometrica fails’
Reviewed in ‘Software Showcase’ in ‘Sky and Telescope’, July 2002.
2.0 Astrometry and Photometry
NOTE; a recent update, as described in the postscript of this paper, make Astrometrica an ideal tool for photometry.
I use this package for astrometric measurements as it offers one very useful feature – track and stack. Faint NEO’s are difficult to image because of their fast motion across the sky. Long exposures don’t improve matters as the asteroid just ‘moves’ on to the next pixel. What Astrometrica allows you to do is input the predicted rate and position angle and then stack the images. Each star is then seen as a line of images and out pops, literally, the asteroid as a single point of light ! Astrometrica then calculates the position and produces a report in Minor Planet Centre format.
‘This in my opinion is the best to use for manual NEO work of faint fast movers. As you say the track and stack feature is essential for this work. Herb (Raab) is very fast to answer questions and address problems. My only gripe is that you need to specify orientation of the image (I use an altaz on a poncet platform so orientation changes through the night)’
Astrometry package from Project Pluto.
‘A FULLY automated astrometry package. It can find moving objects and measure their positions on THOUSANDS of images per night. Of limited use to the strictly manual observer like myself, but amazing nonetheless. Integrates seamlessly with Maxim DL and Astronomers Control Panel for control of remote observatory over the internet’
Photometric analysis of CCD images is done with my own LYMM software which has been written over the last several years. It was developed especially for time series photometry of faint or moving objects.
LYMM is very different to most commercial photometry software!
LYMM is a command line
program, and has no graphics whatsoever, so it is necessary to use it in
conjunction with a program which does (I use
LYMM insists on rigourous image alignment and accurate positions. Forget about software which can only track a star if there is minimal movement from one frame to the next! LYMM calls a star search algorithm to find all the stars above a threshold in all the images you wish to process. You then define several fiducial stars, which are visible in all the images. LYMM then uses a pattern recognition algorithm to find the offsets and rotations, relative to the first, of all the subsequent images in the series.
The image alignment table must be set up, before stacking images or doing photometry. Stacking images is then very easy - see the example.
LYMM gives you various methods of determining positions, and in particular allows positions to be determined using the information in all the frames. Positions may be derived from centroids or PSFs; and you may use an individual frame, a stack of frames, or combine the positions determined in a number of individual frames.
LYMM works well with moving objects. It converts the observed coordinates back to the standard reference system and then fits a curve so that smoothly varying positions - unaffected by noise - are available for the photometry. LYMM includes a powerful feature for assessing field star contamination to an asteroid light curve. The solution to 'what is the contamination at position n?' may be estimated easily by having the program do photometry at this position, but in (almost) all the other frames when the asteroid is somewhere else!
LYMM can even be used for moving objects so faint that several frames have to be stacked to obtain a reliable position. Having defined the motion model, one can then perform photometry of object, which is almost invisible in the individual frames. (And why go to the trouble of using individual frames? Because stacks of frames have the problem that the field star PSFs differ more from that of the asteroid).
LYMM offers a choice of two photometry methods: aperture photometry or optimal photometry (the latter for stationary objects only). You can do photometry of up to 10 stars at once.
A PDF manual for the LYMM software is available (285 kb).
If you are interested in the finer points of CCD photometry, you are strongly recommended to read Tim Naylor's paper, 'An optimal extraction algorithm for imaging photometry', MNRAS, vol 296, pp 339-346. You can access this via Tim's home page.
3.0 Integrated packages
MPO is a suite of programs for
asteroid observers including; observation planning, telescope and camera
control, image analysis and shape modelling. Each of the programs; Connections
(telescope and camera control),
‘Brian (Warner) has probably done more than anyone to open up photometry to the amateur. I suppose a time will come when amateur observations of asteroids will no longer be useful. Armed with MPO I will be ready for that day..........’
A software suite for NEO observing including; observation planning tools, astrometry measurement, MPC format reports and orbit computation.
A complete software for image processing, photometry, astrometry, CCD control and image stacking for CCD and film
To quote from the web site; ‘AstroPlanner is a software application for
Macintosh and Windows computers that facilitates astronomical visual
observation planning and logging as well as control of Meade telescopes that use
the LX200, LX200
A suite of programs to automate observing. This package will; automatically pilot the scope, command the CCD camera and analyze images. For Windows 95 or higher supporting version 3 of the ASCOM protocols.
4.0 Image Processing Packages
Included with ‘The Handbook of Astronomical Image Processing’, both reviewed in ‘Sky and Telescope’, June 2001. The software, as does the book, covers almost every possible aspect of image processing. The software includes tutorials so you can practice your image processing on the images provided and check that you come up with the right results. Reviewed in ‘The Astronomer’, September 2001.
General purpose image processing and analysis freeware by Christian Buil.
The acronym stands for "LIght Measurement tool for
Occultation observation using VIdeo rEcorder"! Limovie fulfils a longstanding need of video
observers to *automatically* derive light curves from captured video recordings
of lunar and asteroidal occultations.
Limovie is also ideal for producing photometry of planetary satellite
mutual events (occultations and eclipses), and can be used for meteor photometry.
A fuller description, by
6.0 Solar System Dynamics
SOLEX is a free computer program modelling the N-body dynamics of the Solar System, and it is the result of a long and patient amatorial work by the author (Aldo Vitagliano). Its heart is a powerful numerical integrator, and the many additional functions make it a greatly flexible program, which at the same time is very simple to use and very powerful in its performances. It can just give aesthetic pleasure and help in identifying sky objects, or it can be used by an experienced researcher as a tool to investigate aspects of the solar system dynamics such impact probabilities and chaotic motion. Last but not least, the software package contains a companion orbit-determination program (EXORB), suitable for the determination of orbital elements of minor bodies (asteroids and comets) from their astrometric observations.