File Extension Database

Open FITS File

The Flexible Image Transport System (FITS) is a digital file format used mainly by scientists working in the field of astronomy. FITS files are designed to store scientific data and related metadata with high precision, making them an essential tool for researchers. In this article, we will discuss the possible formats of FITS files and ways to open and use them.

Understanding FITS File Structure

FITS files can be divided into two main categories: primary and extension. The primary FITS file contains a main data array, whereas the extension FITS files have various types of data arrays like images, tables, or metadata. These files are organized into a series of Header/Data Units (HDUs), which carry metadata in the form of a collection of key-value pairs in the header and the data in the data array. The header and data units facilitate easy reading and processing of the FITS files. For more information about FITS files, visit the FITS primer prepared by NASA's Goddard Space Flight Center.

Image Formats in FITS Files

There are different types of image formats used in FITS files. The primary image format is a two-dimensional array of integers or floating-point values. Extensions to the FITS standard support three-dimensional images, such as spectral data cubes or time-series data with multiple image planes. For more information on various image formats supported by the FITS standard, refer to the FITS standard document.

Opening and Viewing FITS Files

There are several tools available to open and view FITS files. Some popular ones are:

DS9 (SAOImage) - A popular and versatile astronomical imaging and data visualization tool. Available for Windows, macOS, and various UNIX platforms.
Aladin - A well-known interactive sky atlas that allows users to visualize, manipulate, and analyze astronomical data stored in FITS files. Available for Windows, macOS, and Linux.
TOPCAT - A Java-based application designed for working with tabular data in FITS and other file formats. Available for Windows, macOS, and Linux.

Working with FITS Files

For researchers and developers who need to work with FITS files, there are several programming libraries available that provide dedicated support for reading, writing, and manipulating FITS data. Some popular programming languages and their corresponding libraries include:

Python: Astropy - A community-developed library for astronomy that includes the astropy.io.fits module dedicated to handling FITS files.
Java: nom-tam-fits - A well-documented library providing an API for reading, writing, and manipulating FITS files in Java.
C: CFITSIO - A widely-used library for reading, writing, and modifying FITS files, provided by NASA's Goddard Space Flight Center.
R: FITSio - A package for reading and writing FITS files in the R programming language.

FITS File Important Information

FITS files are vital to the scientific community, particularly astronomers, astrophysicists, and others working with astronomical data. Understanding their structure, formats, and various tools available for opening, viewing, and working with FITS files is critical for those interested in utilizing them for research. The links provided throughout this article offer detailed information about the different aspects of FITS files and guidance on how to effectively use them.

How Can I Open FITS File on Windows

We researched and learned that the best way to open FITS file is to find a FITS file in question in Windows OS File Explorer and double click on it to launch the corresponding application.
If a FITS file is not opened in an application and you instead get a "Windows can't open a file" error message you should try looking for an application which can open the file in question.
If you know the application which can open FITS file then run it and see if there is a File->Open main menu option in the application.
If you don't know the application which function as FITS file opener then try to search online for "FITS viewer", "application to open FITS file" or "open FITS file" queries in the search engine you like.
Install the application you found and check if it can open FITS file

How Can I Open FITS File on Mac OS

We recommend to find a FITS file in question in Mac OS Finder and double click on it to launch the corresponding application.
If a FITS file is not opened in a Mac OS application and you instead get a "There is no application set to open the file" error message you can click on "Search App Store" in the error dialog and Mac OS will show you applications compatible with FITS file.
If you know the Mac OS application which can work as FITS file opener you can choose the "Choose Application..." option in the error box to associate the file extension and open FITS file in it.
If you don't know the application which can open FITS file then try to search for "FITS viewer", "application to open FITS file" or "read FITS file" queries in the online search engine you like.
Install the application you found and check if it can read FITS file

How Can I Open FITS File on Android

If you downloaded a FITS file on Android device you can open it by following steps below:

In the Android apps list on your Android device find "My Files" or "File manager" app and tap to start it.
Tap on "Downloads" folder inside the app.
You should see your downloaded FITS file in that folder.
Tap on the file. If Android device supports opening the file you downloaded it will open in the corresponding app.
If file does not open you can look for the corresponding app that can open the file by searching Android App Store for the "FITS".
If you cannot open the file with the apps from Android App Store it is possible that the file could only be opened on desktop platforms such as Windows or Mac OS. Try searching for "FITS viewer", "FITS file reader" online and see if any desktop applications can open it.
It is also possible that the file you downloaded is outdated and is no longer supported.

How to Open FITS File on iPhone or iPad

To open FITS File on iOS device follow steps below:

We advies to open Files app on your iPhone or iPad device. You can find it by swiping down on the home screen and typing "Files" in the search bar.
Tap on the Downloads folder on the Files app home screen.
You will see all files that you recently downloaded. Tap on the FITS file to view it.
If you have the right app that can open it it will automatically launch and open your file.
If you don't have the app which can open it you need to serch Apple app store for "FITS". This way you can find apps which can open FITS files.
If this doesn't help it is possible that your file could be opened only by the desktop application. To find an app which can open it on desktop look for "FITS viewer" or "FITS file" online in your favorite search engine.

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