QUIET SUNSPOTS: Near the center of the solar disk, growing sunspot AR1850 directly faces Earth. However, like all the other spots on the sun today, AR1850 is quiet and not flaring. The chance of a geoeffective flare today is low. Solar flare alerts: text, voice.
MAGNETIC ERUPTION: A filament of magnetism curling over the sun's northeastern limb erupted on Sept. 24th around 20:30 UT. NASA's Solar Dynamics Observatory caught the structure hurling part of itself into space:
Watch the movie and pay attention to the base of the explosion. A "canyon of fire" forms as the filament cuts through the sun's lower atmosphere. The glowing walls of the canyon trace the original channel where the filament was suspended by magnetic forces above the stellar surface.
As erupting magnetic filaments often do, this one launched a coronal mass ejection (CME) into space: image. The cloud does not appear to be heading for Earth. Aurora alerts: text, voice.
COMET ISON ON TRACK TO BECOME 'IMPRESSIVE': Amateur astronomers around the world are photographing Comet ISON as it approaches Mars in the predawn sky. The comet is not as bright as some forecasters expected. What does that mean for ISON's future prospects? The answer may be found below this color photo of the comet obtained by UK astronomer Damian Peach on Sept. 24th:
Photo details: 17" CDK with FLI-PL6303e camera. LRGB. L: 5x3mins. RGB: 1x2mins. Sun -18 to -14deg.
At the moment, Comet ISON is about as bright as a 14th magnitude star, which puts it one or two magnitudes dimmer than forecasts. Nevertheless, according to several experts speaking in a NASA video, Comet ISON is still on track to become an impressive sungrazer. John Bortle predicts ISON will rival Venus during the hours leading up to its closest approach to the Sun in November, while Matthew Knight notes that Comet ISON is brighter than Comet Lovejoy was at the same distance from the sun in 2011. As many readers remember, Comet Lovejoy went on to become a spectacular naked-eye object. Comet ISON might do the same.
New images of the comet are coming in every day. Browse the gallery for the latest views:
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Solar wind
speed: 398.3 km/sec
density: 1.5 protons/cm3
explanation | more data
Updated: Today at 1617 UT
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X-ray Solar Flares
6-hr max: B4 1227 UT Sep25
24-hr: B4 1227 UT Sep25
explanation | more data
Updated: Today at: 1600 UT
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Daily Sun: 25 Sep 13
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Sunspot AR1850 is growing, but solar activity remains low. Credit: SDO/HMI
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Sunspot number: 56
What is the sunspot number?
Updated 25 Sep 2013
Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days
Update 25 Sep 2013
The Radio Sun
10.7 cm flux: 108 sfu
explanation | more data
Updated 25 Sep 2013
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Current Auroral Oval:
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Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
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Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2 quiet
explanation | more data
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Interplanetary Mag. Field
Btotal: 3.7 nT
Bz: 2.4 nT north
explanation | more data
Updated: Today at 1617 UT
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Coronal Holes: 25 Sep 13
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There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
