X4.97! We had an X-Class flare just past midnight UTC on Feburary 25, 2014!
This is the largest solar flare since an X5.4 on March 7th, 2012. This flare originated in newly numbered region 1990. We’ve been monitoring region 1990 since it rotated off the West limb as region 1967 two weeks ago. This is the third rotation this region has been active. In it’s first rotation it was numbered 1944, last rotation it was 1967. As 1967 it produced over 20 M-class flares and held promise to produce an X-class flare. As 1967 it never did produce the promised X-class flare. Now, as it rotates onto the disk as region 1990 it makes good on those promises.
How big is X4.97? Huge. Flares are classified based on how much x-ray radiation reaches Earth. Background x-ray flux of B5 from the Sun is .0000005 Watts per meter squared. A C-class flare has 10x the x-ray density (.000005) as measured at the ACE satelite. An M5 flare is 10x higher again. Today’s X4.97 is another 10 times as powerful at .000495, or one-thousand times more x-rays than the Sun produces when there is not a flare. That means today’s flare was almost 5 times stronger than the biggest flare on 1990’s previous rotation as region 1967.
This flare, while huge, was not well positioned for an Earth-Directed CME. The majority of the ejecta will go to the East of Earth. There is enough ejecta associated with this flare that Earth will probably feel at least a glancing blow, but it will likely be very slight.
We will be keeping an eye out for more large flares from this region over the next two weeks. It has been producing flares and CMEs during it’s transit across the back side of the Sun. There is no reason to expect it won’t continue producing flares and CMEs during it’s transit as Region 1990. It will be best positioned for Earth-directed CMEs in about 7 days. If we get an X-class flare anytime between Feb 26-27 and March 4-5, there’s a better chance for Aurora as a result.
Our Sun has given us a CME kiss for Valentines day this year.
The SWPC has announced two geomagnetic storm watches for this weekend:
The first is a G1 storm watch on Valentines day, from midnight to midnight. This means Kp values are predicted to exceed 5. Converting the times to EST, this watch lasts from 7:00pm EST Thursday, Feb 13 through 7:00pm EST Friday night.
The second, immediately following the first watch, from midnight to midnight UTC on February 15th, is a G2 storm watch. This means Kp values are predicted to exceed 6. Converting the times to EST, this watch lasts from 7:00pm EST Friday, Feb 14 through 7:00pm EST Saturday, Feb 15 evening.
What this means: This weekend is a great time to be monitoring the Kp values on NothernLightsNow.com. If the Kp value exceeds your local Kp threshold take a peak outside, you might see northern lights if it isn’t cloudy. Use this last minute guide for preparing to go Aurora hunting.
These watches are the result of two Earth-Directed CMEs that launched from the Sun on Feb 11th and 12th from solar region 1974 (Beta-Delta-Gamma). The CME on February 11th is actually a combination of a CMEs from an M1 flare and a CME from a 15 degree filament. The second CME was launched during an M3 flare.
This region has been very active over the last several days and has produced 9 M-class flares. It has continued to grow in area and is now 460 millionths. It has maintained it’s Beta-Delta-Gamma structure with three delta spots. We can’t rule out a larger flare in the near future, but the region is rotating out of geo-effective range.
Viewing conditions are not ideal for the next two nights. The Moon is very close to full. In much of the US and europe it will be cloudy. There will be some lucky areas in Canada, Iceland, Alaska, the northern-midwest US and Scotland and Denmark where the clouds clear out and aurora may be visible.