100 millionth image from SDO. Credit: SDO
Almost hard to imagine, one hundred million images from the Solar Dynamics Laboratory!
Congraduations to the AIA team!
Yesterday, January 19, 2015, at 1749 UTC (12:49 pm ET) the AIA instrument recorded its 100,000,000th image. Here it is, an AIA 193 Å image showing coronal holes in both the northern and southern hemispheres. More information, including some favorite images from team members, is available at the NASA SDO webpage.
The AIA team at LMSAL worked hard to design and build the AIA telescopes, even overcoming a delayed start way back at the beginning of the SDO project. The team continues to operate the instrument, keeping it calibrated and listing the features seen on the Sun. The HMI JSOC team at Stanford University maintains the archive that serves the images to our large and growing number of users.
Sunspot group AR2257 produces a flare. Image Credit: NASA/SDO
A beautiful shot of the Sun by the Solar Dynamics Observatory showing the rather impressive first flare of the new year. The flare was produced by the sunspot group AR2257.
I mentioned last week conditions seemed right for an aurora (from this sunspot group). While I didn’t see an aurora on that time out and an aurora is not likely from this particular flare any longer, I would expect to have other viewing opportunities over the next months as the solar cycle progresses. Flares can become more numerous as the solar cycle passes peak activity. We shall see.
This flare/sunspot group did produce a pulse of UV radiation that ionized the upper atmosphere over Australia and the Indian Ocean. The ionization could have impacted HF radio frequencies below about 10 Mhz – being a ham operator these events are important.
Could this be the start of increased activity? Possibly and these things can happen quickly. You can be alerted when an aurora is apt to occur from a few sources. Two of my favorites is Aurora Service Europe based in Scandinavia and as always, Spaceweather.com.
Here is the NASA caption released with the image:
The sun emitted a mid-level solar flare, peaking at 11:24 p.m. EST on Jan. 12, 2015. NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth’s atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel.
The sun on 01 Jan 2015. Image Credit: NASA/SDO
An image of the sun on 01 Jan taken by the Solar Dynamics Observatory. The image is dominated by a large coronal hole in the southern hemisphere. As the sun rotates we should get an idea of the extent of the size.
NASA’s Dean Pesnell explains:
Coronal holes are regions of the corona where the magnetic field reaches out into space rather than looping back down onto the surface. Particles moving along those magnetic fields can leave the sun rather than being trapped near the surface. Those trapped particles can heat up and glow, giving us the lovely AIA images. In the parts of the corona where the particles leave the sun, the glow is much dimmer and the coronal hole looks dark.
Coronal holes were first seen in images taken by astronauts on board NASA’s Skylab space station in 1973 and 1974. They can be seen for a long time, although the exact shape changes all the time. The polar coronal hole can remain visible for five years or longer. Each time a coronal hole rotates by the Earth we can measure the particles flowing out of the hole as a high-speed stream, another source of space weather.
Charged particles in the Earth’s radiation belts are accelerated when the high-speed stream runs into the Earth’s magnetosphere. The acceleration of particles in the magnetosphere is studied by NASA’s Van Allen Probes mission.
As Solar Cycle 24 fades, the number of flares each day will get smaller, but the coronal holes provide another source of space weather that needs to be understood and predicted.