Friday, June 21, 2019

Happy Summer Solstice and Congratulations to Phil Scherrer!

Today at 1554 UTC (11:54 a.m. ET) the Sun reached its most northerly point in the year. As a result, we have the most daylight hours in the northern hemisphere and the Southern Hemisphere has the most dark hours. At the solstice the Sun appears to stall and turn around, heading towards the south and northern winter. It's the official beginning of summer and all because the Earth's rotation axis is tilted 23° from the plane of its orbit. Here's an AIA 193 Å to celebrate.

But today is also a day to congratulate Phil Scherrer of Stanford University who is also the HMI PI and the person who watches over the JSOC with the HMI and AIA data. Dr. Scherrer was awarded the Solar Physics Division's Hale Prize last week at the 234th Meeting of the AAS. The Hale Prize is awarded annually to a scientist for outstanding contributions to the field of solar astronomy.

Dr. Scherrer has certainly made contributions to solar physics. He has measured and studied the Sun's magnetic field for 50 years. As important, he has encouraged others to use his data as well. He has also worked in helioseismology, both measuring the velocities of the Sun's surface and the theory of ow those measurements tell us something about the Sun. It is hard to know what our field would look like if he hadn't been around.

Congratulations Phil!

Friday, June 14, 2019

Listening to the Sun

Ever wish you could listen to SDO data? We have developed new ways to do just that!

This week the American Astronomical Society and the AAS Solar Physics Division had a joint meeting in St Louis. Astronomers and solar physicists got together to discuss our latest papers on understanding the Sun and universe.

Two of those papers were "Listening to the Sun" (by Kyle Ingram-Johnson, W. Dean Pesnell, and Kevin Addison) and "Listening to the Sun: the Sonification of Solar Harmonics Project" (by tim larson, Seth Shafer, and Elaine diFalco). Both papers allow you hear different kinds of SDO data. They were presented as iPosters, so they are available at the links below for others to read through and enjoy.

This paper converts several solar indices to sound before sonifying AIA images in three ways. You can listen to the entire image, small subsets of the image, and a series of images that shows a filament liftoff. We used a special math curve called a Hilbert curve to walk around the image and convert the pixels values into a set that can be then converted to sound. You should listen to the difference between the full image sonified with a Hilbert curve and sonified with a left-right scan. You will see a big difference.

The next paper shifts HMI sound waves from their very low frequency of about 3 mHz to about 3 kHz so you can hear the tones.

You are working to allow you to sonify images, both the entire image and as subsets, on the SDO website. Look for that new feature in the future.

Until then, please enjoy listening to the Sun!