Image: Solar Dynamics Observatory spies rare encircling filament

November 9, 2017, NASA
Credit: NASA/GSFC/Solar Dynamics Observatory

NASA's Solar Dynamics Observatory came across an oddity that the spacecraft has rarely observed before: a dark filament encircling an active region (Oct. 29-31, 2017). Solar filaments are clouds of charged particles that float above the sun, tethered to it by magnetic forces.

They are usually elongated and uneven strands. Only a handful of times before have we seen one shaped like a circle.

The black area to the left of the brighter active region is a coronal hole, a magnetically open region of the sun.

While it may have no major scientific value, it is noteworthy because of its rarity. The still was taken in a wavelength of .

Explore further: Image: NASA's Solar Dynamics Observatory watches a sunspot

Related Stories

Image: NASA's Solar Dynamics Observatory watches a sunspot

August 7, 2017

On July 5, 2017, NASA's Solar Dynamics Observatory watched an active region—an area of intense and complex magnetic fields—rotate into view on the Sun. The satellite continued to track the region as it grew and eventually ...

SDO sees a dark filament circle

November 26, 2015

A dark, almost circular filament broke away from the sun in a gauzy, feathery swirl, on Nov. 15, 2015, in this video from NASA's Solar Dynamics Observatory. This filament eruption was followed by a second filament breaking ...

Video: SDO sees active region outbursts

November 10, 2015

This close-up video by NASA's Solar Dynamics Observatory shows an active region near the right-hand edge of the sun's disk, which erupted with at least a dozen minor events over a 30-hour period from Nov. 3-5, 2015.  

Recommended for you

Study details the history of Saturn's small inner moons

May 22, 2018

The small inner moons of Saturn look like giant ravioli and spaetzle. Their spectacular shape has been revealed by the Cassini spacecraft. For the first time, researchers of the University of Bern show how these moons were ...

Two bright high-redshift quasars discovered

May 21, 2018

Astronomers have detected two new bright quasars at a redshift of about 5.0. The newly found quasi-stellar objects (QSOs) are among the brightest high-redshift quasars known to date. The finding was presented May 9 in a paper ...

First interstellar immigrant discovered in the solar system

May 21, 2018

A new study has discovered the first known permanent immigrant to our Solar System. The asteroid, currently nestling in Jupiter's orbit, is the first known asteroid to have been captured from another star system. The work ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

cantdrive85
1 / 5 (4) Nov 09, 2017
The black area to the left of the brighter active region is a coronal hole, a magnetically open region of the sun.
While it may have no major scientific value,

Magnetically open, the author is unknowingly correct that comment has no scientific value.
AlfvenArp
1 / 5 (2) Nov 09, 2017
"While it may have no major scientific value" ... really?! It is an observed process that is taking place that you don't have any viable explanation for and that in and of itself gives it scientific value.
cantdrive85
1 / 5 (2) Nov 09, 2017
Clearly a sockpuppet, most likely da schnied. All magnetic flux is a closed loop, calling something "magnetically open" is meaningless mumbo jumbo.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.