news
Submitted on 2012-11-10
Once again, last week's activity was not particularly exciting: Just a few small single sunspots, that was it! Also, the SIDC announced that the provisional sunspot number for October was 53.3. That is the lowest since February this year. What a difference with the sunspot activity one year ago: Several groups dotted the solar surface during that November month, and also the biggest sunspot group so far this solar cycle (NOAA 1339) made its appearance. Obviously, one wonders if SC24-maximum has already passed.
Submitted on 2012-11-02
On October 23, active region NOAA1598 produced the 15th X-class flare of the current solar cycle (SC). The X1.8 was of short duration, lasting only 8 minutes. It did not produce an energetic particle event (proton event), and there was no obvious indication of an ejected plasma cloud.
Submitted on 2012-10-25
On 20 October, the Sun unleashed an impulsive M9-flare. This flare peaked at 18:14UT in sunspot group NOAA 1598, which was at the time of the blast still partially behind the southeastern solar limb. One already has to go back to 12 July to find an even stronger flare (X1.4 in NOAA 1520).
The flare did not last long: Starting at 18:05UT, it already had come to its end by 18:19UT. No high-energetic protons were released at the time of the flare, and only a slow and weak coronal mass ejection (CME), directed away from Earth, was associated with it. |
Submitted on 2012-10-18
As discussed in the previous STCE Newsletter, the very Long Duration Event from 5 October propelled a coronal mass ejection (CME) towards Earth. From the SOHO and STEREO imagery, forecasters concluded that this CME would deliver a glancing blow late on 8 October or on 9 October. |
|
Submitted on 2012-10-11
In the morning hours of 5 October, the Sun produced a relatively weak B7.8 flare. Interesting were its atypical x-ray evolution and its very long duration. Indeed, starting at 03:17UT, it reached its maximum x-ray intensity only at 07:30UT. Ending at 10:46UT, the flare lasted for a whopping 7 hours and 29 minutes, and that begged for some closer examination. As it turns out, this was a very complex event. |
 |
|
Submitted on 2012-10-04
On 27 September, the Sun produced 2 almost identical, small solar flares: A C4.4-flare peaking at 17:20UT, and a C3.7-flare at 23:57UT. However, except for their near-equal strength, these eruptions differed quite a bit from each other, and they had also a very different impact on Earth. |
 |
|
Submitted on 2012-09-27
PROBA2 is an ESA micro-satellite that was launched on November 2, 2009. It carries an on-board camera to image the Sun in the Extreme Ultra-Violet (EUV). The images obtained with this SWAP-instrument show the solar corona at 1 million degree, with a cadence of 1 image per 1-2 minutes, and a field of view (FOV) of minimum 1.7 solar diameters. More information on this imager is available at the SWAP-webpage. |
|
Submitted on 2012-09-20
Filaments are clouds of cooler gas trapped between magnetic fields of opposite polarity. Seen in suitable filters, they look like dark lines and strands against the hotter solar disk. Near the limb, when their silhouette is observed, they glow as towering, torches, hedges and arches. They are then called prominences. |
|
Submitted on 2012-09-13
Even when a solar cycle is close to its maximum, it may happen from time to time there are periods with low solar activity. This is especially true when the maximum is predicted to be already low to medium, as is the case for ongoing solar cycle 24. |
Space weather forecasters can issue an alert when solar activity is extremely low. This "all quiet alert" is a message sent when quiet space weather conditions are expected for the next 48 hours or until further notice. This implies that:
|
Pages
Zircon - This is a contributing Drupal Theme
Design by
WeebPal.
