Starship Asterisk*

APOD Robot wrote:
AR1520: Islands in the Photosphere

Explanation: Awash in a sea of plasma and anchored in magnetic fields, sunspots are planet-sized, dark islands in the solar photosphere, the bright surface of the Sun.

They lie in the center of active region AR1520, now crossing the Sun's visible face. In fact, an X-class solar flare and coronal mass ejection erupted from AR1520 on July 12, releasing some of the energy stored in the region's twisted magnetic fields. Headed this way, the coronal mass ejection is expected to arrive today and may trigger geomagnetic storms. As a result, some weekend auroral displays could grace planet Earth's skies along with Sunday's predawn conjunction of bright planets and crescent Moon.

http://www.universetoday.com/96286/incoming-cme-on-its-way-toward-earth/#more-96286 wrote:

Click to play embedded YouTube video.

Computer model of the CME from Goddard Space Weather Center.
Impact with Earth is expected on 7/14 at 6:20 am EDT.

Incoming! CME On Its Way Toward Earth
by Jason Major, Universe Today, July 13, 2012

<<As you read this, a huge cloud of charged solar particles is speeding toward our planet, a coronal mass ejection resulting from the X1.4-class flare that erupted from sunspot 1520 on July 12. The CME is expected to collide with Earth’s magnetic field on Saturday, potentially affecting satellite operations and tripping alarms on power grids, as well as boosting auroral activity. It’s on its way, and all we can do is wait. (Thank goodness for magnetospheres!)

Actually, the effects from the incoming CME aren’t expected to be anything particularly dramatic. NOAA is predicting a geomagnetic storm level raging from G2 to G4, which although ranges from “moderate” to “severe” a G2 (Kp = 6) is most likely, according to Dr. C. Alex Young from NASA’s Goddard Space Flight Center.

“A G2 level storm can cause some power fluctuations that may set off some voltage alarms for power companies,” Dr. Young told Universe Today. “Damage to transformers is possible for longer events, but unlikely. Satellite companies may have to make some orbit corrections for their satellites, and at higher latitudes where there are aurora they can be some disruption of high frequency radio broadcasts. “All in all the effects should be minor,” he concluded.

And this may not be the last we hear from 1520, either. “Its complexity has decreased but it is still large and has a ‘delta’ configuration,” added Dr. Young, “when there is opposite polarity magnetic field of the umbra within the penumbra of the sunspot. This is an unstable configuration that is indicative of larger releases of energy, lots of flares — in particular M and X flares.”

Auroras may be visible at lower latitudes this weekend, so check the NOAA’s updated auroral oval map to see if visibility extends into your area over the next several nights. Hopefully aurora photographers around the world will be able to get some great photos of a summer sky show!>>

Moonlady wrote:
Finish scientiest believe they detected aurora caused sound!

http://asterisk.apod.com/viewtopic.php?f=8&t=29077

owlice wrote:APOD on Facebook

Borc wrote:

owlice wrote:APOD on Facebook

I know, I'm sayin It'd be cool if there was a direct link on apod.nasa.gov to 'like/share on fb/twitter' technically the apod on fb is not directly affiliated with apod, and is run by a fan.

ritwik wrote:
ppl want to see aurora but no CME

The sun emitted a large flare on July 12, 2012, but earlier in the week it gave a demonstration of how gorgeous solar activity can be. This movie shows the sun from late July 8 to early July 10 shortly before it unleashed an X-class flare beginning at 12:11 PM EDT on July 12 as captured by the Solar Dynamics Observatory (SDO). The flare isn't shown here, but the movie shows how the sun is constantly, and complexly, active. The region responsible for the flare, known as Active Region 1520, and sitting in the lower left part of the sun, crackles with giant loops of magnetized solar material that can help scientists understand how magnetic energy in the region creates these giant explosions. On the right side of the sun, the shimmering loops offer us the last vision of Active Region 1515 – which was also responsible for many solar flares -- as it disappears out of view along with the sun's rotation. The movie represents light in the 171 Angstrom wavelength, a wavelength of light that is particularly good at highlighting these magnetic loops.

n X1.4 class flare erupted from the center of the sun, peaking on July 12, 2012 at 12:52 PM EDT. It erupted from Active Region 1520 which rotated into view on July 6.

This video uses SDO AIA footage in 131(teal), 171(gold) and 335 (blue) angstrom wavelengths. Each wavelength shows different temperature plasma in the sun's atmosphere. 171 shows 600,000 Kelvin plasma, 335 shows 2.5 million Kelvin plasma, and 131 shows 10 million Kelvin plasma.

The final shot is a composite of 171 and 335 angstrom footage.