Nuclear Spectroscopic Telescope ARray

NASA’s small explorer satellite NuSTAR was built to observe various X-ray emitting astrophysical objects in the sky. However, it can also be pointed to the Sun, enabling research in  high-energy heliophysics.


> Science: occulted flares and active regions, quiet Sun flares, microflares, axion search

> Computer science: support in data analysis tools

Project lead at I4DS: Säm Krucker

Partners: University of Glasgow, University of Minnessota, UC Santa Cruz, Caltech

Funding: SNF
> Link to initial project
> Link to follow up project

Start: 2013
Status: ongoing

Keywords: high-energy physics, solar physics, NASA



NuSTAR is an X-ray Earth-orbiting telescope used for observations of astrophysical objects such as supernova remnants, black holes, active galactic nuclei (AGN), and the center of our Milky way. However, the telescope can also be pointed at the sun, delivering data of interest to the solar physics community due to its great sensitivity. The project at the Institute for Data Science uses this opportunity to address two research questions: 1) coronal heating by microflares, and 2) mechanisms of electron acceleration in flares and coronal mass ejections (CMEs).


Prof. Dr. Säm Krucker


Dr. Matej Kuhar

Solar Physicist



NuSTAR has a 10-m mast to separate the optics modules (right) from the detectors (left). NuSTAR has two identical optics modules in order to increase sensitivity. The background is an image of the Galactic center obtained with the Chandra X-ray Observatory. Artist’s concept, image courtesy NASA/JPL-Caltech
NuSTAR typically stares deeper into the cosmos to observe X-rays from supernovas, black holes and other extreme objects. But it can also look safely at the sun and capture images of its high-energy X-rays with more sensitivity than before. This image combines observations from several telescopes on July 8, 2015. High-energy X-rays from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) are shown in blue; low-energy X-rays from Japan’s Hinode spacecraft are green; and extreme ultraviolet light from NASA’s Solar Dynamics Observatory (SDO) is yellow and red. Image courtesy NASA/JPL-Caltech
X-rays stream off the sun in this image showing observations from NuSTAR, overlaid on a picture taken by NASA’s Solar Dynamics Observatory (SDO). This is the first picture of the sun taken by NuSTAR. It was taken on December 22, 2014. The field of view covers the west limb of the sun.  Image courtesy NASA/JPL-Caltech

This video highlights a variety of bright points and structures even though the Sun is nearing the minimum of its activity cycle, without any active regions or flares present. NuSTAR gives a unique view of the energetic processes that are present on the quiet Sun, helping to understand how the atmosphere of the Sun is heated. Video courtesy NASA/JPL-Caltech