Imaging the Sun (2) ...

The X-ray image in the above figure was taken in 1992 with the Yohkoh Soft X-ray Telescope (SXT). Since X-rays are normally emitted from objects having temperatures of millions of degrees, this indicates that such hot spots occur in the Sun's upper atmosphere and corona. It is not completely understood why the Sun is producing the broad diffuse X-ray glow seen in this image. Here is the most recent Yohkoh image, and here is a chance to make a movie of SXT observations.

The UV image shown in the figure above was taken by the Solar and Heliospheric Observatory (SOHO). It represents light emitted by highly charged iron ions at high temperature. In the image, lighter regions are at temperatures of about one million degrees while darker regions are somewhat cooler.

The adjacent right animation shows the Sun in UV at 1600 Angstroms over a several minute period on November 15, 1999. It also shows a transit of the planet Mercury. Because Mercury emits little UV radiation, it appears as a dark disk against the UV emission from the Sun.

Sources of Current Solar Images

Many of these images are updated on a daily or at least regular basis. Here are current solar images in specific wavelength bands:

• SOHO Fe IX,X (171 Å)
• SOHO Fe XII (195 Å)
• SOHO Fe XV (284 Å)
• SOHO He II (304 Å)
• Yohkoh Soft X-ray
• National Solar Observatory (Kitt Peak) Photospheric Magnetograms
• National Solar Observatory (Kitt Peak) He I 10830 Å Spectroheliograms
• National Solar Observatory (Kitt Peak) Ca II 8542 Å Magnetograms
• National Solar Observatory (Sacramento Peak) Ca II K Spectroheliograms
• Mauna Loa Solar Observatory White -Light Coronameter

Current Solar Movies