Looking to explore the night sky but don’t want to break the bank on expensive astronomy software? Look no further! In this post, I’ll explore some, but not all, of the top open source and freeware software options for amateur astronomers. Discover all the features and tools you need to take your imaging to the next level without spending a dime.
There are plenty of fantastic and expensive software applications that provide “free trials” of 30-90 days before they entice you to pay for a license to continue to use them. And that’s fine. If you don’t pay they’ll just make using them difficult by shutting off critical functionality or locking you out altogether until you do pay. I get it. You got to pay to play! But these software titles below are all free to download and use with no restrictions, but please understand that most of these will also have an option to “donate or contribute” money to those hard working folks that have spent hours of their time to bring these “free” applications to you.
So if you find yourself repeatedly using one or several of these applications I highly encourage you to do as I have done – show them some love, hit the donate button and contribute to their cause.
Post Processing / Image Manipulation Software
AstroSharp – A free astrophotography open source software that is getting attention right now is “AstroSharp” by DeepSkyDetail. AstroSharp is a new AI powered deconvolution tool. What’s that? Simply put it’s a software that sharpens images! Cuiv, The Lazy Geek recently put the new AstroSharp to the test up against BlurXterminator which is one of, if not the, leading sharpening tools. His conclusion? BlurXterminator might be superior to AstroSharp but that doesn’t mean it’s not worth keeping AstroSharp in your toolkit.
GraXpert – If you’re an astrophotographer you’ve no doubt ran into the issue at some point of gradients in your images and the need to remove them. There are a few gradient removal freebies out there that, to be honest, don’t work that well, and then there are several options that work great but will set you back $50-$100. Enter GraXpert an open source software that claims to remove those pesky gradients from your images. There are versions for Windows, Mac and Linux. This video tutorial comes from graxpert.com and covers everything from what a gradient is to installation instructions and tips and tutorial for using the software.
GIMP – GNU Image Manipulation Program (GIMP) is a free cross-platform image editor available for Linux, Mac and Windows as well as others. It’s an image manipulation and editing software that I have to admit that I have not used. I pay for a subscription to Adobe Photoshop but many people do use it extensively for editing their astro images and have great results. You can download it free here: https://www.gimp.org/
Siril – Siril is an astronomical image processing tool. It is specially tailored for noise reduction and improving the signal to noise ratio of an image from multiple captures. Siril can align automatically or manually, stack and enhance pictures from various file formats, even image sequence files (films and SER files). I have to admit this one is on my list to check out. See more at siril.org
Astrophotography Imaging Suite
N.I.N.A. – N.I.N.A (Nighttime Imaging ‘N’ Astronomy) – “Be it for beginners or for advanced astrophotographers, N.I.N.A. will keep configuration requirements to the minimum and will assist you through the process of imaging. N.I.N.A. offers a broad variety of capabilities. The toolset spans from choosing, framing, focusing, centering and imaging one or multiple targets and much more. This project is fully free and open source while welcoming every feedback and contributions.” I switched from APT (Astro Photography Tool), which I have a paid license to use, about a year and a half ago to N.I.N.A. and have not looked back. I’ve found N.I.N.A to be extremely intuitive to use. It was easy to setup and configure, it’s well supported and if you do run into issues it’s easy to find solutions via the Discord chat server or YouTube videos. It just works extremely well for me.
Image Stacking Software
DeepSkyStacker – If you’re looking to align and stack multiple images into one cohesive frame, DeepSkyStacker enhances your ability to capture elusive details that would be otherwise difficult to capture with a single image. DSS even has several settings for stacking comets. I use this application to stack all my images and it works well.
Autostakkert! – AutoStakkert! is all about alignment and stacking of image sequences, minimizing the influence of atmospheric distortions (seeing). Its goal is to create high quality images of the Planets, the Sun, and the Moon, without too much hassle.
ASTAP or “Astrometric STAcking Program,” is an astrometric solver and FITS image viewer. This program can view, measure, “astrometric (plate) solve” and stack deep sky images. It’s main features include stacking of astronomical images including dark frame and flat field correction, Native fast astrometric (plate) solver, alignment using an internal star match routine, internal Plate Solver, manual or ephemeris and FITS viewer. I use it for plate solving and love it. It’s super fast and it works.
FireCapture – FireCapture is a feature-rich astronomy program, designed by Torsten Edelmann. Its purpose is to control the operation of cameras used in high speed digital video imaging of the planets and other solar system objects.
RegiStax6 – RegiStax is image processing software used primarily for alignment, stacking and processing of images. This application for amateur astrophotographers is released as freeware, designed to run under Windows, but which also runs on Linux.
Sequator – Sequator can track stars on multiple images, align stars and stack them. Sequator is a great choice for those using just a DSLR and tripod setup. It’s a powerful tool for those just entering astrophotography and starting off with a simple setup. There are many other software titles in this category to be sure but these are the ones I have used, heard of or seen mentioned the most.
Planetarium Software
Let’s talk about some amazing planetarium software titles for a moment. Planetarium applications allow a user to simulate the celestial sphere at any date and time, especially at night, on a computer. You can manipulate the date and time in the software to show you exactly what the sky would look like in the past or future. This can be extremely helpful when planning what to observe or image, and maybe more importantly this software can tell you when to observe specific events. Data from planetarium software can also be passed to a motorized telescope mount in order to precisely point at objects in the sky making observing objects easy.
There are many planetarium titles out there to choose from. Here are a couple that top the list.
Stellarium is a hugely popular open source, free planetarium that I use extensively both on my desktop, imaging laptop and mobile device. I find Stellarium to be excellent in simulating the night sky. It displays stars, constellations, planets, nebulae and DSOs, comets and asteroids as well as the ground, landscape, atmosphere, etc. I also use it to feed coordinates to my imaging software (N.I.N.A.).
Sky Chart / Cartes du Ciel – Cartes du Ciel or “Map of the Sky” offers a full suite for astronomical observation and planetarium functionality. There is a large following that use CDC for the specific purpose of pointing their telescopes via an ASCOM driver. “SkyChart is a software to draw charts of the night sky for the amateur astronomer utilizing a several star and nebulae catalogs.” I confess that I have not used CDC as of yet but many folks do and are very fond of it.
Guiding Software
PHD2 (Push Here Dummy) – PHD2 is free, open source, and community-developed and supported guiding software. PHD2 simplifies the process of tracking a guide star, letting you concentrate on other aspects of deep-sky imaging. PHD2 handles these measurements automatically by sending guide pulses to your telescope mount and watching how far and in which direction the star moves between guide camera images. This process begins after you have selected a star and then clicked on the PHD2/Guide icon button.
Telescope Aiming/Pointing Software
AstroHopper – The New “AstroHopper” open source software/web site allows Dobsonian telescope owners a free option for aiming their scopes, or any Alt/Az telescope for that matter. The only thing you need is a smartphone. I have not tried this software out myself but it looks promising. It’s available on GitHub here. Celestron’s proprietary “StarSense Explorer” smartphone app which is only available with activation code supplied with a new Celestron telescope purchase stands to loose in this matchup. The YouTube “Reflactor” channel did a nice video reviewing and providing “how to” instructions and tips for using this web based tool.
In conclusion, the vast universe is now more accessible than ever, thanks to the plethora of free astronomy and astrophotography software applications available to enthusiasts and professionals alike. Whether you’re exploring the night sky or capturing stunning celestial images, these tools, and many more that are not listed here, empower us to embark on cosmic journeys from the comfort of our own devices. So, grab your telescope, set up your camera, and immerse yourself in the boundless wonders that await in the vast expanse of space. Happy stargazing and clear skies!