A Rapidly Changing Sun - Feb 4, 2015

These images of the Sun were taken on Wednesday, February 4, 2015 at the Phoebe Waterman Haas Public Observatory at the National Air and Space Museum in Washington, DC.

The image at left, taken at 11:55 am EST, shows the surface of the Sun, speckled with many tiny sunspots.  The largest one is the size of the Earth.  

Visitors to the Public Observatory got a triple treat when using a hydrogen-alpha telescope to observe the atmosphere of the Sun in red light.  The big red image of the Sun was taken at 2:37 pm EST and displays a number of interesting features.

The large dark feature at left is a filament, an arch of gas above the Sun.  Though it had not fully rotated into view yet, this one was as long as the distance from Earth to the Moon.  This dramatic filament continued to captivate solar observers for days afterward.

At 1:43 pm EST, a nondescript group of sunspots just left of the Sun's center, AR 2280, released a solar flare, an explosion of energy.  Though this was only a minor C3-class solar flare, it lasted an unusually long time - nearly an hour.

The detail images at lower right show the effects of the flare over several hours.  Earlier in the day at 11:55 am EST, the tiny dark sunspots were surrounded by a plage, a bright cloud of hot gas above the Sun's surface.  The flare heated up the plage, making it glow brighter, as can be seen in the center detail.  That image was taken as the solar flare was just starting to fade.  Just 27 minutes later, the effects of the flare had faded, and the plage returned to approximately its original brightness.

While visitors, volunteers, and staff monitored the progress of the solar flare, they received another surprise.  Seemingly out of nowhere, a prominence erupted high above the Sun's surface.  It is visible on Sun's upper left in the center image, and in the detail images at upper right.  A prominence is the same thing as a filament: an arch of gas above the Sun.  In fact, this new prominence is clearly connected to another filament, illustrating how the two objects are part of the same feature.  It's called a "filaprom."  The prominence looks bright against the darkness of space, while the filament looks dark against the brighter surface of the Sun.

Over the course of just half an hour, this prominence continued to expand outward, dissipate, and fade, as shown in the last image at upper right.

The Sun looks different every day, and on an unusually lucky day like this one, it can change from minute to minute!

Telescope: Lunt 100mm hydrogen-alpha

Camera: Lumenera SKYnyx 2-2M