mercredi 22 octobre 2014

Second Substantial Flare in Two Days












NASA - Solar Dynamics Observatory (SDO) patch.

October 22, 2014

The sun emitted a mid-level solar flare, peaking at 9:59 p.m. EDT on Oct. 21, 2014. NASA's Solar Dynamics Observatory, which is always observing the sun, captured an image of the event. The same active region previously emitted an X1.1 solar flare on Oct. 19. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel.


Image above: An active region on the sun erupted with a mid-level flare on Oct. 21, 2014, as seen in the bright light of this image captured by NASA's Solar Dynamics Observatory. This image shows extreme ultraviolet light that highlights the hot solar material in the sun's atmosphere. Image Credit: NASA/SDO.

To see how this event may affect Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.


Image above: An active region on the sun erupted with a mid-level flare on Oct. 21, 2014, as seen in the bright light of this image captured by NASA's Solar Dynamics Observatory. This image shows extreme ultraviolet light that highlights the hot solar material in the sun's atmosphere. Image Credit: NASA/GSFC/SDO.


Image above: An active region on the sun erupted with a mid-level flare on Oct. 21, 2014, as seen in the bright light of this image captured by NASA's Solar Dynamics Observatory. This image shows extreme ultraviolet light that highlights the hot solar material in the sun's atmosphere. Image Credit: NASA/GSFC/SDO.

This flare is classified as an M 8.7-class flare.

M-class denotes flares that are a tenth as strong as X-class flares, which are the most intense flares. The number provides more information about its strength. An M2 is twice as intense as an M1, an M3 is three times as intense, etc.

Coronal Loops, Anyone?

Video above: SDO captured a splendid example of expanding coronal loops seen in profile at the edge of the Sun (Oct. 14-15, 2014). The bright loops began to form and grow after a long-lasting M-class flare erupted. The arcs of the loops we see in extreme ultraviolet light are actually particles spiraling along magnetic field lines arcing above the active region that was the source of the flare. They are reorganizing the magnetic field after its disruption. To give a sense of scale, these huge loops are reaching out more than 15 times the size of Earth. Video Credit: Solar Dynamics Observatory/NASA.

Updates will be provided as needed.

What is a solar flare?

For answers to this and other space weather questions, please visit the Spaceweather Frequently Asked Questions page: http://www.nasa.gov/mission_pages/sunearth/spaceweather/index.html

Related Links:

X1.1 solar flare on Oct. 19: http://orbiterchspacenews.blogspot.ch/2014/10/nasas-sdo-observes-x-class-solar-flare.html

Related multimedia from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11717

What does it take to be X-class?: http://www.nasa.gov/mission_pages/sunearth/news/X-class-flares.html

View Past Solar Activity: http://www.nasa.gov/mission_pages/sunearth/multimedia/Solar-Events.html

For more information about Solar Dynamics Observatory (SDO), visit: http://sdo.gsfc.nasa.gov/ and http://www.nasa.gov/mission_pages/sdo/main/

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Karen C. Fox.

Greetings, Orbiter.ch