Tuesday, November 23, 2021

APOD - The Sun in X-rays from NuSTAR

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2021 November 23
The featured image shows the Sun in X-ray light as  shown by NASA's NuSTAR satellite -- superimposed on an image  in ultraviolet light taken by NASA's Solar Dynamic Observatory.  Please see the explanation for more detailed information.

The Sun in X-rays from NuSTAR
Image Credit: NASA, NuSTAR, SDO

Explanation: Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead -- even much higher up in the Sun's corona -- can be hundreds of times hotter. To help find the cause, NASA directed the Earth-orbiting Nuclear Spectroscopic Telescope Array (NuSTAR) satellite to point its very sensitive X-ray telescope at the Sun. Featured here is the Sun in ultraviolet light, shown in a red hue as taken by the orbiting Solar Dynamics Observatory (SDO). Superimposed in false-colored green and blue is emission above sunspots detected by NuSTAR in different bands of high-energy X-rays, highlighting regions of extremely high temperature. Clues about the Sun's atmospheric heating mechanisms come from NuSTAR images like this and shed light on solar nanoflares and microflares as brief bursts of energy that may drive the unusual heating.

Tomorrow's picture: stellar sisters


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.


This is an automated email. If you notice any problems, just send me a note at gtracy@gmail.com. You can add and remove email addresses to this distribution list here, https://apodemail.org.Unsubscribe

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.