(Many of) The Best Things in Astronomy are Free

By Bill Pellerin, GuideStar Editor

Houston Astronomical Society


The autoguiding software that I use for my variable star imaging works great and you can get it on the Internet for free. (I made a donation to the creator of this software because I like the software very much, and to encourage further development.) The software I use to get images from the camera to the computer came with the camera at no additional charge. The image processing software that I use to dark subtract and to stack images was downloaded from the camera manufacturer’s web site at no charge. The software does everything that I need done.


The software used to analyze the images and determine star magnitudes resides somewhere in cyberspace and is available to me because I’m a member of the American Association of Variable Star Observers (AAVSO), so it’s almost free.


I used free software to calculate field-of-view and image scale for various chip and telescope combinations. I use the free ASCOM software that provides the connection between software and the telescope and the imaging hardware. My observation planning software and my sky mapping software are both bought-and-paid-for commercial products, and worth every penny.


There is a lot of other free (and useful) software that I don’t use. There’s software for automatically focusing your telescope; there is software that assists in polar aligning your telescope mount; there is more sophisticated image processing software; and, of course, sky mapping and telescope control software.

I haven’t even mentioned the free (or very inexpensive) software you can get for your mobile device (that’s what they’re called these days). Some of it is extraordinarily useful. One little application that I have tells me when sunset and sunrise are (and moon phase). Really important information for observers. There are plenty of weather applications for your personal computer and for your handheld.


Amateur astronomy has the reputation of being an expensive endeavor. It can be, but it doesn’t have to be. My home club, the Houston Astronomical Society, was recently visited by Robert Reeves. Robert lives in San Antonio, and is the author of several books including Introduction to Digital Astrophotography, Wide Field Astrophotography, and Introduction to Webcam Astrophotography.


Robert Reeves has spent a lot of time recently photographing the moon in high resolution. He is using an 8” SCT that he has owned for over 30 years, a nice equatorial mount, and a relatively inexpensive camera for his work. He has used a webcam in the past, and webcams are quite inexpensive. He fitted the telescope with some mirror-locking bolts (to eliminate image shift when focusing) and added an external focuser to the back of the telescope tube. He uses the software that came with the camera for image capture, and he uses free image stacking software that he downloaded from the Internet.


Why would people give away their computer programming effort for free, or almost for free? It could be for any one or all of several reasons. They may enjoy the act of creating and debugging the software; they may enjoy contributing to the astronomical community something of value; they may want or need some software that doesn’t already exist, so they decide to write it themselves (and share it with others).

What about the hardware? My home club has a stable of telescopes that are available for members to take home and use at no cost. There’s also an 18 acre observing site about 80 miles out of town available at the cost of membership. There are also club-owned telescopes, in an observatory, at the observing site, that are available to members following a short training course.


If you live near a university or in a large city there may be telescopes that go unused much of the time (for any one of various reasons). If you volunteer to help, you may find that the telescope is available for you to use.


How can you study astronomy for free? There is a torrent of research information that’s available at no cost. Your public library wants to put astronomy books in your hand so you can learn something new. The Internet is replete with new information on what’s going on in the world of astronomy. Webcasts, podcasts, and online college courses are all over the Internet, many for free.


So, look for resources that are available to you. You’d be surprised how much is available at little or no cost. If you want to do astronomy (even research) you can do it. Get creative, think about possibilities, ask around, get involved. You may soon find that your only limitation is the time to use all that’s available to you.


Scroll to top Astronomical League