OUR SUNBig Bear is down right now. Here is an alternate site for up to date solar images at National Solar Observatory at Sacramento Peak.:
http://nsosp.nso.edu/data/latest_solar_images.html
OUR SUN
This solar image is updated every minute. It comes from Big Bear Solar Observatory, Big Bear Lake, Calif.
Hydrogen Alpha (H-Alpha) images of the sun are images obtained through a narrow band, red filter, centered at 6562.8 Angstroms or 656.28 nm. This color is sensitive to the activity of hydrogen gas on the sun. See below and here for details. Here are some nice images of the sun through a variety of filters. Details on calicum K filters and images.
The dark streaks and patches seen in the H-Alpha images are called filaments. Filaments are prominences seen in front of the disk of the sun, as opposed to sticking out from the edge of the sun. The bright regions are called plages or faculae. The filaments and plages are found in regions of strong magnetic activity at the solar surface. Sunspots are typically found in conjunction with these other phenomena. All are driven by the 22 year magnetic cycle of the sun which is responsible for the sun spot cycle.
Here is a nice gallery of solar images with explanations.
This is a very recent, maybe today, giant H-Alpha image of the sun. Prominences can be seen projecting from the edge of the sun when the sun is active.
Here is the full catalog of recent Big Bear Solar Observatory images and movies. There are some nice movies showing the last 24 hours and the last 60 days (which are more interesting).
Here is Big Bear's archive of some of their best images.
When the moon covers the sun we get spectacular solar eclipses. 
Solar activity is also responsible for the aurora borealis.
Here are the home pages of a number of solar observatories:
Here are some web sites with more information on the sun:
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Prepared by Fritz Kleinhans, Physics - IUPUI, for Explore IUPUI Day, Oct 12, 2002
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Technical Information
from Coronado Instruments:
Light from the Sun has a unique 'signature' imposed upon it from the various elements which make
up its composition. This becomes visible by stretching the light out into a spectrum. Superimposed
on the spectrum will be seen many dark lines or 'absorption' lines where the continuous
illumination, from deep red to violet, has been filtered out by the action of these elements, at
different levels of the Sun' structure, as the light proceeds outwards and on into space.
If one uses an instrument which allows observing the Sun at one of these lines, the solar disc will
be observed in only the element that produced that particular line.
Although observations can be made at almost any of the myriad lines in the spectrum,- and, indeed
are at solar observatories around the world,- there are some lines which are more important than
others in showing the major phenomena going on in the life of our Sun. At a wavelength of 656.28
nanometres, (nm), is the main signature of the element Hydrogen. As this was the first hydrogen
line mapped in the spectrum, it is referred to as 'H-alpha'. Further along, deep in the violet end of
the spectrum is the main signature of Calcium,- the so-called calcium-K line or, simply, Ca-K.
This line is at a wavelength of 394.4nm.
These two lines alone tell us much of what goes on on the Sun and allow observations of the
majority of the more critical phenomena;- solar prominences, the structure around sun spots,
flares, granularity, etc, etc.... and, as the vast proportion of the Sun's constitution consists of
hydrogen,- the most important of these lines is H-alpha.
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