View Full Version : One Huge Sunspot, 2003/10/22
2003-Oct-23, 08:21 PM
I observed the gigantic active region AR 10484 on Wednesday afternoon. It was the one of the easiest to detect naked-eye sunspots that I've ever beheld and was unmistakable through my polymer solar shades. I was able to see considerable internal detail with my Celestron C4.5 Newtonian at 53, 72, and 82x. I also noted the CME producing sunspot AR 10486 working its way in from the trailing limb.
2003-Oct-23, 10:49 PM
i saw this at www.sec.noaa.gov/
quite impressive, current 'strong' Radio blackouts
HF Radio: Wide area blackout of HF radio communication, loss of radio contact for about an hour on sunlit side of Earth.
Navigation: Low-frequency navigation signals degraded for about an hour.
also -from space.com-
A strong dose of space weather is forecast to hit Earth Friday, potentially disrupting satellite communications and posing a threat to power grids on Earth. The event also presents a nice opportunity for anyone to view sunspots, though safe viewing techniques must be employed to prevent eye damage.
The storm of charged particles was unleashed by a dark region on the solar surface called Sunspot 484. The huge spot, about the size of Jupiter's surface, has been growing for several days and rotating into a position that now points squarely at Earth.
Another giant sunspot is brewing and more storms could be generated.
Sunspots are cooler regions of the Sun where magnetic energy wells up, often prior to eruptions.
The sunspot let lose a storm of energetic particles, known as a coronal mass ejection at 3 a.m. ET Wednesday, according to forecasters at the National Oceanic and Atmospheric Administration (NOAA). The expanding cloud is expected to arrive midday Friday. It could produce a geomagnetic storm rated G3 on a scale that goes up to G5.
The activity is expected to generate colorful aurora, or Northern Lights into the northern U.S. states and much of northern Europe. Meanwhile, a continuing "coronal hole" is already providing aurora farther north, in places like Alaska and northern Canada.
The storm comes as the Sun is actually in a declining mode of activity. An 11-year solar cycle peaked during 2001 and 2002. Sunspots are fewer now and activity will ramp down during the next three to four years. But, scientists say, isolated severe space weather can occur at any time.
"It’s somewhat unusual to have this much activity when we’re approximately three-and-a-half years past solar maximum," said Larry Combs, a forecaster with the NOAA Space Environment Center’s Space Weather Operations. "In fact, just last week, solar activity was very low with an almost spotless Sun."
Space weather has hampered satellite communications before.
In 1997, an AT&T Telestar 401 satellite used to broadcast television shows from networks to local affiliates was knocked out during a solar storm. In May 1998 a space storm disabled PanAmSat's Galaxy IV, used for automated teller machines and airline tracking services, among other things. Another storm in July 2000 put several satellites temporarily out of contact and caused navigation problems in others.
Warning of impending storms allows satellite operators to reduce the risk of damage to some satellites by shutting down electronics.
Even cell phones can act up during solar storms, causing dropped calls.
In 1989, a solar storm tripped protective switches in Canadian Hydro-Québec power company. All of Québec lost power for nine hours. The problem nearly spread to the United States through an interconnected grid. Power companies have since developed programs to safeguard their systems, but experts say they remain at risk.
Forecasters said a second sunspot, developing and about to rotate into an effective position on the Sun's surface, could produce additional stormy weather over the next couple of weeks. In fact early Thursday it unleashed a major flare of its own, one that could generate some space weather near Earth even though it wasn't pointed directly at us. That glancing blow would arrive late Friday or, more likely, Saturday. .
2003-Oct-24, 02:09 AM
After you mentioned it, I took my telescope out, pointed it at the Sun, and took a look at the image projected onto a piece of paper. Pretty amazing sunspot right in the middle of the Sun.
You can do this with binoculars too, but whatever you do, don't look at the Sun. Instead, project it onto a piece of paper. Here's some instructions on how to do this here:
Do it tomorrow, it's really cool!
2003-Nov-04, 03:21 PM
:huh: seems to remain quite active
here extracts from bbc
What is happening to the Sun?
By Dr David Whitehouse BBC News Online science editor
The Sun's intense activity in the past week will go into the record books.
Scientists say they have been amazed by the ferocity of the gigantic flares exploding on the solar surface.
The past 24 hours have seen three major events erupt over our star, hurling billions of tonnes of superhot gas into space - some of it directed at Earth.
...On Monday, there was an X3 flare followed by smaller ones.
Last week there were X7 and X10 events that took place back-to-back. Flares with an X rating are unusual and, if the gas cloud from them reaches the Earth, are capable of causing a geomagnetic storm.
The Earth's changing magnetic field in such a storm can cause power grid and satellite problems. Japanese engineers believe that one of their satellites failed last week because of one such storm.
Last week's flares came from giant Sunspot 486, as did the first flare on Sunday. Subsequent flares have emanated from Sunspot 488 which appears to be growing in activity. Some experts are saying that the Sun is more active than it has been in living memory.
Dr Paal Brekke, deputy project scientist for the Solar Heliospheric Observatory (Soho) Sun-monitoring satellite, told BBC News Online: "It is quite amazing that the flaring regions continue releasing such strong flares.
"I think the last week will go into the history books as one of the most dramatic solar activity periods we have seen in modern times. "As far as I know there has been nothing like this before."
more extracts -and different X scale- from space.com
Sun on Fire, Unleashes 3 More Major Flares
By Robert Roy Britt
Senior Science Writer
posted: 10:45 am ET
03 November 2003
UPDATED AT 11:31 A.M. ET
The Sun cut loose with three severe flares in less than 24 hours through Monday morning, bringing to nine the number of major eruptions in less than two weeks.
Scientists have never witnessed a string of activity like this.
Colorful aurora are expected to grace the skies at high latitudes and possibly into lower portions of the United States and Europe over the next two or three nights. Satellites and power grids could once again be put at risk.
Early Monday, Paal Brekke, deputy project manager of the SOHO spacecraft, was still digesting the significance of the three additional outbursts on top of two back-to-back monster flares Oct. 28 and 29.
"I think the last week will go into the history books as one of the most dramatic periods of solar activity we have seen in modern time," Brekke told SPACE.com.
By the numbers
The flares this week began with an X8 event at 12:25 p.m. ET Sunday. On this scale, all X-storms are severe, and the number indicates the degree of severity. An X3 flare erupted at 8:30 p.m. Sunday.
Reports of the third flare are preliminary. It left the Sun at 4:55 a.m. Monday and is estimated to be an X4. The trio of outbursts comes within a week of the unprecedented, back-to-back severe flares rated X17 and X10.
The first four flares in this long, amazing series date back to Oct. 22 and were ranked less than X2.
All flares of this magnitude are capable of disrupting communications systems and power grids and harming satellites. Two Japanese satellite failures and a power outage in Sweden were blamed on the first six storms.
The new flares were accompanied by coronal mass ejections of charged particles that take anywhere from 18 hours to two or three days to reach Earth. These CMEs represent the brunt of the storm unleashed by a flare.
A storm's precise strength, however, cannot be known until about 30 minutes before it strikes and depends on the orientation of its magnetic field. If that field is southward -- opposite the direction of Earth's north-pointing magnetic field -- then the potential is greatest for accelerating the local particles that can then damage satellites and fuel aurora.
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