Why are the solar flare and cme black

[Mckinnon]

Why are the sloar flare and cme photos just black ? Are they under matience?

[Marcel de Bont]

The images from SDO are currently black due to a calibration maneuver. They point the spacecraft away from the Sun a couple of times as you can see in this video for example https://sdo.gsfc.nasa.gov/assets/img/latest/mpeg/latest_1024_0193.mp4

The maneuver should be over within the next couple of hours.

[Jacob_CX_Cooper]

I've always thought that CMEs and solar flares are black on photos because these areas have a lower temperature in comparison with other parts of the Sun, or am I mistaken?

[Marcel de Bont]

32 minuten geleden, Jacob_CX_Cooper zei:

I've always thought that CMEs and solar flares are black on photos because these areas have a lower temperature in comparison with other parts of the Sun, or am I mistaken?

You are mistaken. Let us begin with solar flares. Solar flares are explosions on the Sun comparable in strength with millions of nuclear bombs going of all at once. These events generate enormous amount of radiation in the form of light and heat. The light emitted is mostly in the EUV and X-ray spectrum. Solar flares are easily observed as very bright flashes on imagery from SDO's AIA instrument. The 131 Angstrom channel is very well suited to spot these eruptions.

Coronal mass ejections are clouds of solar plasma being blasted away from the Sun in to interplanetary space. These clouds are faint compared to the Sun but we can make them visible by using coronagraphs. SOHO has such an instrument on board as well as the STEREO space craft. On these images you can often see these clouds as they travel away from the Sun into interplanetary space.

This video is a great example of what a solar flare looks like followed by the resulting coronal mass ejection. We have many more such videos in our archive if you are interested.

https://www.spaceweatherlive.com/images/Archief/2014/Flares/201402250049X4.9.mp4

You must be thinking about coronal holes, these are indeed dark areas on the Sun in certain wavelengths. https://www.spaceweatherlive.com/en/help/what-is-a-coronal-hole.html