FITS File – What is .fits file and how to open it?

What is a FITS File?

A FITS file is a file format used to store and transfer astronomical data. It was developed in the 1980s by a group of astronomers working at the Space Telescope Science Institute (STScI). The FITS format is designed to be flexible and extensible, and it can be used to store a wide variety of astronomical data, including images, spectra, and catalogs.

FITS files are typically organized into a series of extensions. Each extension contains a different type of data, such as an image, a spectrum, or a catalog. The primary extension is the first extension in the file and it typically contains the most important data. The other extensions are optional and they can be used to store additional data or information.

FITS files are widely used by astronomers around the world. They are the standard format for storing and exchanging astronomical data, and they are supported by a wide variety of software applications. FITS files are also used to store data from a variety of space-based telescopes, including the Hubble Space Telescope and the Chandra X-ray Observatory.

Opening FITS Files

FITS (Flexible Image Transport System) is a format designed to store and exchange scientific data, particularly in the field of astronomy. FITS files are commonly used to store images, spectra, and other scientific data. To open a FITS file, you can use specialized software or use general-purpose image viewers.

Using Specialized Software:

Several software packages are specifically designed to handle FITS files. These programs offer a range of features for viewing, editing, and analyzing FITS data. Some popular options include:

• SAOImage DS9: A free and open-source image viewer and analysis tool widely used in astronomy.
• ImageJ: A powerful image processing and analysis platform that supports FITS files.
• PyRAF: A Python-based package that provides tools for astronomical data analysis, including FITS file handling.

Using General-Purpose Image Viewers:

Some general-purpose image viewers can also open and display FITS files. However, they may not offer the specialized features of dedicated FITS viewers. Some common options include:

• GIMP: A free and open-source image editing software that supports FITS files.
• Adobe Photoshop: A professional-grade image editing software that can open and edit FITS files with the appropriate plugins.
• Windows Photo Viewer: A basic image viewer included with Windows that can display FITS files without any additional software.

Development of FITS

The Flexible Image Transport System (FITS) file format was developed by a consortium of astronomers led by the National Aeronautics and Space Administration (NASA) and the Space Telescope Science Institute (STScI). The initial development began in the early 1980s to create a standardized way of storing and exchanging astronomical data among different observatories and software platforms. The first version of the FITS specification was released in 1981, and it has undergone several revisions over the years to accommodate new data types and technologies.

Features and Usage of FITS

FITS is a hierarchical file format that can store both image data and associated metadata in a single file. The basic unit of data in a FITS file is the Header Data Unit (HDU), which consists of a header and a data array. The header contains information about the data, such as its dimensions, units, and coordinate system. The data array contains the actual image data. FITS files can contain multiple HDUs, which allows for the storage of multiple images or other data types within a single file. This flexibility makes FITS a widely used format for storing and distributing astronomical data. It is supported by a wide range of software applications and libraries, making it easy to read and write FITS files in various programming environments.

Other Extensions