Major X-Class WHITE-LIGHT Solar Flare Alertgreenspun.com : LUSENET : TB2K spinoff uncensored : One Thread
From: Cary Oler
Subject: AstroAlert: Major X-Class WHITE-LIGHT Solar Flare Alert - 06 June Date: Tue, 6 Jun 2000 23:42:11 -0600 (MDT)
A s t r o A l e r t Sun-Earth Alert
Solar Terrestrial Dispatch http://www.spacew.com Link
06 June 2000
* Major X-Class WHITE-LIGHT Solar Flare Alert * * Stereo Movie of X-Class Flare *
Detailed images, movies and resources available at: http://www.spacew.com/astroalert.html
(We apologize for the delay in posting this. It has taken a while to assemble the resources together after performing all the post-flare analyses that are required.)
Active sunspot region number 9026 produced a flurry of very energetic solar activity on 06 June. Two X-class flares occurred between 13:10 and 17:00 UTC (9:10 am and 1:00 pm EDT) on 06 June. The largest X-class flare was an enormous X2.3 x-ray event. In the light of hydrogen, the flaring region covered an area so large you could fit roughly 30 times the entire surface area of the Earth within it.
Today's most powerful X2 solar flare was a rare WHITE-LIGHT flare. A white-light flare is a brightening of the visible photospheric surface of the Sun. Anyone observing the Sun with a simple telescope equipped with a filter that cuts down the brightness of the Sun to safe levels could have observed this event. It occurred at 16:06 UTC and lasted a couple of minutes just as x-rays were increasing to X-class levels. Images and even a movie of this event were captured by Antonio Sanchez-Ibarra at the University of Sonora (Estacion de Observacion Solar [EOS]) using a CCD video camera at the continuum. A movie of this event is available at: http://cosmos.cifus.uson.mx/eosdata.htm link. We congratulate the group there at EOS for a job well done in capturing this event!
An enormous coronal mass ejection, part of which is headed toward the Earth, was observed in conjunction with today's major flare activity. Images and movies of the progress of the halo coronal mass ejection are available at the URLs: http://www.spacew.com/astroalert.html Link and: http://www.spacew.com/c2 or: http://www.spacew.com/c3. The velocity of the coronal mass ejection was clocked to near 1,200 kilometers per second (4.3 million kilometers per hour or 2.7 million miles per hour) by measuring the radio emissions created by the supersonic shockwave of the disturbance as it travelled outward through the inner part of the solar corona.
This Earth-directed disturbance is expected to slam into the Earth's magnetosphere sometime during the mid-to-late UTC hours of 08 June (mid-morning to late afternoon, Eastern Daylight Time on 08 June). The disturbance may hit the Earth with a velocity near or in excess of 2.8 million kilometers per hour (or 1.8 million miles per hour), or about twice the normal velocity of the solar wind.
There is a chance the pressure of the solar wind against the magnetosphere might be strong enough to push the boundary of the magnetosphere inside the orbit of geosynchronous satellites. The passage of satellites into the harsher domain of the magnetosheath (which is a more turbulent region that separates the quiet inner shell of the magnetosphere from the solar wind) can caused some satellites to begin pointing incorrectly at the Earth. Historically, some satellites have lost control completely and have begun tumbling when they have crossed the magnetopause boundary. Exposure to the more direct effects of the solar wind can also degrade the life-span of solar arrays and other exposed surfaces. Increases in radiation levels in space resulting from the disturbed conditions produced by the disturbance may also result in single event upsets on spacecraft electronics caused by surface charging anomalies. And increased atmospheric drag caused by the ballooning of the Earth's atmosphere during increased periods of geomagnetic and auroral activity can lower the orbital altitudes of orbiting spacecraft. All of these effects may play a role in the upcoming events.
Auroral activity is expected to increase to storm levels on 08 and 09 June. Whether activity will become strong enough to observe from many middle or low latitude locations won't be known for certain until after the disturbance begins passing the Earth when spacecraft will be able to directly sample the characteristics of the solar wind. But forecasters have a hunch the disturbance could be moderately large, perhaps in the G2 to G4 category range for geomagnetic storms (on a scale from G1 [minor] to G5 [extreme]). Region 9026 does not appear to have changed very significantly following today's major solar flare. We'll know more tommorrow, but for now it still appears to be a potentially very volatile sunspot group. Additional major M and X class flares are possible. And even another white-light flare may be observed.
Among the various movies and images describing this event is one which stands apart from the rest. The Solar Terrestrial Dispatch, in collaboration with the Kanzelhohe Solar Observatory and the National Solar Observatory at Sacramento Peak, New Mexico, has produced an experimental stereoscopic movie spanning 30 minutes (or 13 frames) of the major flare observed today (a small portion of the overall event). This is, to our knowledge, the first ever near-realtime stereoscopic movie of a major X-class solar flare in the light of hydrogen. Those who are interested can find it at: http://www.spacew.com/stereo-flare.mpg Link. To see the 13 frames in stereo, look THROUGH your monitor, forcing your eyes to focus beyond the plane of your monitor's screen until the two solar images merge into a single stereo view of the Sun. Tilt your head very slightly left or right, or move your head toward or away from the monitor until the images merge into a single coherent view of the Sun. Then (without changing focus), have your movie viewing software begin playing the movie in a loop. It's aesthetically rather cool and scientifically potentially valuable to produce these types of movies.
** End of AstroAlert **
-- Space Man Spiff (firstname.lastname@example.org), June 07, 2000