The sun has recently emitted a wave of dazzling solar flares and, within the short space of just two days, NASA officials have witnessed three such events. The strongest was recently unleashed this Friday, and was captured by the space agency’s Solar Dynamics Observatory (SDO).
The First M9.4 Solar Flare
The first recent solar flare was witnessed on Oct. 23. Captured images of the beautiful display revealed a spectacular M9.4-class solar flare, peaking at 8:30 p.m. EDT. The image shows light in the 131 Angstrom wavelength, ideal for witnessing the scorching heat, produced during the violent phenomenon; displaying light in this wavelength also yields an
image that is predominately teal-colored.
Since the solar flare has been labeled as an M9.4, this places it at the top end of the rating scale. Solar flares are classified as A, B, C, M or X, corresponding to the peak flux (watts/square meter) of 100 to 800 picometer X-rays close to Earth. For each class, an arbitrary scale from one to nine is also applied (with the exception of the X-class).
Consequently, an M9.4 solar flare represents a very spectacular release of energy, and was also associated with a coronal mass ejection (CME). The CME was directed towards Earth, but remained relatively weak. In contrast, more formidable solar activity can culminate in intense geomagnetic storms that influence global satellite positioning signals and power grids.
NASA has used experimental research models to demonstrate how the Oct. 23 CME may join up with two additional CMEs, which left the sun shortly before, on Oct. 22, 2013. Check out the footage to see the simulation:
Meanwhile, the output of highly energetic particles can interact with atoms within the upper atmosphere, causing an increase in the appearance of Earth’s auroras, a phenomenon known as the northern lights. Previously, these types of solar flares have even triggered radio blackouts at the Earth’s poles.
Latest Solar Flare Events
The sun then emitted a second solar flare, during the early hours of Oct. 25, 2013. The Solar Dynamics Observatory snapped this event in the 131 Angstrom wavelength. However, unlike the previous solar flare, Friday’s earliest flare was much stronger and was classified as an X1.7. As indicated previously, the X-class of solar flare is the most powerful and, according to a recent NASA press statement, have been responsible for causing “… degradation or blackouts of radio communications for about an hour.”
As previously indicated, the “X” denotes the most intense solar flares, whilst the number provides additional information as to the strength between the different X-class events. So, an X2 solar flare is twice as intense as an X1 flare, whilst an X3 flare is three times more intense, and so forth.
The latest solar flare, to garner the attention of the SDO space satellite, is stated to have peaked at 11:03 a.m., on the morning of Oct. 25. Remarkably, the flare belonged to the X2.1 class of flare.
As indicated in the image, the flare was, once more, observed by the SDO, with the images showing a combination of wavelengths at 193 and 131 Angstroms; it is shown as an intensely bright flash, situated towards the left of the sun.
What Are Solar Flares?
Solar flares are sudden releases of energy, witnessed over the surface of the sun, with magnitudes that can scale up to a sixth of the total energy output from the star, each second. They are often followed by enormous coronal mass ejections.
These solar flares often occur around sunspots, where magnetic fields penetrate the light-emitting photosphere, linking the corona to the solar interior. The solar flares are rapidly generated following the release of magnetic energy stored within the corona. Indeed, according to the Space Weather Prediction Center (SWPC), a number of the solar storms that
preceded the X1.7 solar flare resulted from a new sunspot cluster, called Region 1882. However, geomagnetic storms are not expected within Earth’s magnetic field, as these events were not aimed directly towards Earth.
The sun is currently in the “peak year” of its 11-year activity cycle, also known as the Solar Cycle 24. The 24th solar cycle began on Jan. 4, 2008, with minimal activity witnessed up until 2010. The solar cycle represents the periodic change in the sun’s activity, including variation in the ejection of solar material and the appearance of high-temperature sunspots. These cyclic events have a concomitant impact upon Earth’s weather and climate.
However, it is perfectly normal for numerous solar flares to be witnessed during the sun’s peak activity. The first X-class flare of this current cycle occurred in February 2011, whilst the largest X-class flare of the cycle was an X6.9, identified on Aug. 9, 2011.
We look forward to more of these truly dazzling solar displays, in the near future.
By: James Fenner