C'mon, Get Happy!

And if you're not humming a Partridge Family song right now...well...you're younger than I am.

Fall has finally arrived, and I am indeed happy.  I know the official start of Fall was over a month ago, but the weather hasn't really caught up with the fact here until today.  It is brisk and sunny outside, and now the season for good observing can truly get underway.

Apparently the Sun is happy about it as well, since it seems to have decided to put on a show celebrating the change of weather patterns.  Check it out:

The Sun on October 24, 2013.  Courtesy Spaceweather.com.

Every 11 years, the Sun enters a period of maximum activity.  2013 is supposed to be a Solar Max year, but things on the Sun haven't exactly been popping.  In fact, this is one of the weaker solar maximums we've seen in recent history.  But some scientists are forecasting a tick up in activity as we approach the new year, and they may be right.  Those lovely dark areas you see on the face of the Sun are sunspots, and the more spots there are, the more active the solar surface is.  Sunspots are caused when the magnetic field of the Sun breaks through the surface and allows heat to be funneled away, cooling a small region of the surface.  "Cooling" is relative, by the way - the surface of a sunspot is still a toasty 7,000-8,000 degrees Fahrenheit.  But that is substantially cooler than the average 10,000 degrees of the bright solar surface! Oh, and when I say a "small region" of the surface...keep in mind, all those spots you can see on the Sun are bigger than the Earth in diameter.

Here we're seeing the Sun in white light, or the kind of light we normally see.  If we look in a different wavelength...say, ultraviolet...the sunspot regions show amazing amounts of activity.

Bright sunspot region AR1877 snaps off a solar flare.  Photo by the Solar Dynamics Observatory.  Courtesy Spaceweather.com.

The inset image is a single frame from a movie taken by SDO of a solar flare that exploded out from one of the sunspot regions.  The Sun is an incredibly active body, and it is quite amazing to observe.  To safeguard your eyesight, however, always take proper precautions before viewing the Sun:

To safely view the Sun, use:

• an ENDCAP solar filter on a telescope
• Arc welder's glass #14
• Solar Eclipse glasses

NEVER use the following:

• Eyepiece solar filters (they can overheat and break)
• Shades of arc welder's glass other than #14 (not enough protection!)
• Regular or prescription sunglasses (even if they block UV, that is not enough protection!)
• Exposed film
• Viewing the Sun low to the horizon when it appears red (this is NEVER safe!)

As long as your eyes are properly protected, viewing the Sun can be a fabulous experience.  Depending on what kind of filter you use, you may be able to see sunspots, prominences, flares or other types of activity on the Sun's surface.  And these things may change or move right before your very eyes!  Our Sun is an active, exciting star, and it's worth taking a look at.

And right now, the Sun is giving us a whole lotta lovin'.  Enjoy!
Until next time...
Carpe Diem!  :D (and Noctem too!)
Kelly

The Ultimate in Star-Power

Did you have trouble with the radio in your car this past Monday?  Did the GPS in your phone suddenly go on the fritz?  If so, then you've experienced the power of the Sun.

The Sun cracked off a wicked little flare which impacted us this past Monday, disrupting some radio and GPS signals.  Many people don't realize just how much the Sun impacts us.  Sure, we all know it gives us light and heat, but did you know it can cause power outages, disrupt communications, and is responsible for the auroras?  There's an entire industry devoted to predicting what the Sun is going to be doing...it's called space weather.

The area of the Sun which unleashed Monday's solar flare in several different types of light.  The bright spot on each of the pictures is where the flare originated, except on the magnetogram (there the spot appears dark).  Courtesy NASA.

The Sun is a massive ball of plasma - a highly electrically charged state of matter that has similarities to both gases and liquids.  Material comes streaming out of the Sun almost all the time.  But sometimes, the Sun gets pretty stirred up, and it can unleash an extra burst of material on out into space.  If that material happens to be headed in the direction of Earth, we may experience a variety of effects, from the merely beautiful to the highly dangerous.

The most common effect of solar activity is the Northern Lights, or the Aurora Borealis.  These shimmering colored lights are most easily seen in the extreme north (or, if you're living down under, you can see the Aurora Australis in the extreme south), and occur when charged particles from the Sun strike particles in our atmosphere and excite them.  Eventually the particles give up the extra energy they've received from the Sun and produce a variety of colored lights that seem to dance through the sky.  Auroras are amazingly beautiful, and completely harmless.

Red and green auroras over White Dome Geyser in Yellowstone National Park this month.  Picture by Robert Howell.  Courtesy Astronomy Picture of the Day.

Sometimes, when the Sun is really agitated, those particles come in towards the Earth at speeds sufficient enough to allow them to punch down into the lower atmosphere and affect high-voltage power lines.  Since the particles from the Sun are themselves charged...well...this can do very nasty things to equipment designed to send charged particles in only one direction.  We've been able to trace the causes of several wide-scale blackouts back to the impact of solar material.

The flare that disrupted radio and GPS on Monday was not all that intensive.  Scientists track what happens on the Sun so companies with satellites in orbit and power companies can be made aware of when solar material might be on the way.  We expect an uptick in solar events over the next year, as the Sun reaches the peak of its 11-year activity cycle in 2013.  Want to stay up to date on space weather happenings?  Check out spaceweather.com for the latest on solar events.

Until next time, enjoy the sunshine...
Carpe noctem!
Kelly