Organization: 365 Days Of Astronomy
Description: Space scoop, news for children.
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
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This is the 365 Days of Astronomy Podcast. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
The Sun’s More Attractive Than Ever!
Most of us are familiar with magnets; they decorate our fridges and spin about in our compasses. But have you ever wondered how they work?
Each magnet produces something called a “magnetic field”.
This is an invisible region around the magnet where it can pull or push other objects. They have north and south poles. Every kid who has played with magnets knows that opposite poles attract and like poles repel.
For example, with fridge magnets, the magnet pulls on the iron atoms in the fridge’s door. The magnetic field strength is way stronger than the whole Earth’s gravitational field. It easily holds the magnet up.
Our Sun is a giant magnet and so too is the Earth.
Let’s see what this means in terms of strength of magnets. The unit of measurement is the gauss, named for the German mathematician and physicist Carl Friedrich Gauss.
The Earth’s magnetic field is half a gauss. A non-sunspot part of the Sun is about 1 gauss, and sunspots are way stronger, usually 3,000 gauss.
The typical fridge magnet, though, is 100 gauss.
So most of the time the Sun’s magnetic field is pretty weak; about a hundred times weaker than that fridge magnet!
But Japanese scientists just measured a sunspot’s magnetic field that’s more than twice as strong as normal for a sunspot! They were going over data gathered in 2014 by the HINODE spacecraft.
They measured the field by looking at the split absorption lines for iron atoms in the spectrum of the sunspots. This splitting is caused by the Zeeman effect, named after the Dutch physicist Pieter Zeeman.
Check out the Wikipedia page for a deep dive into all this. It’s great fun!
They measured a field of 6,250 gauss in a spot between 2 sunspots, compared to the usual 3,000 gauss.
It was the strongest magnetic field ever measured on the surface of the Sun.
The Sun’s magnetic field also shoots charged particles, helium nuclei, electrons & protons, off its surface at speeds hundreds of kilometers per second.
This is the cause of “space weather” that can damage satellites, interrupt radio signals and endanger astronauts. So, understanding magnetic fields and how they change is crucial!
Hey, Here’s A Cool Fact:
You can think of sunspots as the visible part of upside-down tornados of magnetism. The intense activity deep inside the Sun’s convective zone makes columns of magnetic field energy flow outward.
These columns of magnetism get twisted into a vortex by the different rotation rates between the Sun’s fast spinning equator and the more northerly or southerly parts that rotate more slowly.
If these magnetic flux tubes get strong enough they penetrate the surface and extend out into space.
At the point where the vortex breaks through the surface, the convection of energy from the interior of the Sun is prevented. This makes the sunspot cooler and thus darker than the other parts of the Sun’s photosphere.
If all this spaceweather stuff is fascinating to you, you should visit spaceweather.com regularly!
Thank you for listening to the 365 Days of Astronomy Podcast!
End of podcast:
365 Days of Astronomy
The 365 Days of Astronomy Podcast is produced by Astronomical Society of the Pacific. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrates the Year of Everyday Astronomers as we embrace Amateur Astronomer contributions and the importance of citizen science. Join us and share your story. Until tomorrow! Goodbye!