THE SUN
THE ASTRONOMY PICTURE OF THE DAY 2010 August 28
Hole in the Sun
Credit: NASA / Goddard / SDO AIA Team
Explanation: This ominous, dark shape sprawling across the face of the Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space. Studied extensively from space since the 1960s in ultraviolet and x-ray light, coronal holes are known to be the source of the high-speed solar wind, atoms and electrons which flow outward along the open magnetic field lines. During periods of low activity, coronal holes typically cover regions just above the Sun's poles. But this extensive coronal hole dominated the Sun's northern hemisphere earlier this week, captured here in extreme ultraviolet light by cameras onboard the Solar Dynamics Observatory. The solar wind streaming from this coronal hole triggered auroral displays on planet Earth.
THE ASTRONOMY PICTURE OF THE DAY FOR 2010 JUNE 7
Orange Sun Simmering
Credit & Copyright: Alan Friedman (Averted Imagination)
Explanation: Even a quiet Sun can be a busy place. And over the deep Solar Minimum of the past few years, our Sun has been unusually quiet. The above image, taken
last week in a single color of light called Hydrogen Alpha and then false colored, records a great amount of detail of the simmering surface of our parent star. The
gradual brightening towards the Sun's edge in this color-inverted image, called limb darkening, is caused by increased absorption of relatively cool solar gas. Just over
the Sun's edges, several prominences are visible, while two prominences on the Sun's face are seen as light streaks just above and right of the image center.
Two particularly active areas
of the Sun are marked by dark plages. In contrast to recent quiet times, our Sun is moving toward Solar Maximum, and for years will likely appear much more active.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Posted in: Solar Astronomy, sun by Nancy Atkinson
Image from the Solar Dynamics Observatory of the filaments coming from the Sun's surface. Credit: NASA
The Harvard Smithsonian Center for Astrophysics released the latest information on the July 31/August 1 activity on the Sun that is just now reaching Earth. They predict we'll have multiple opportunities for a display of the Northern Lights over the next two days. The latest word from the solar scientists is that the Sun erupted not just once, but four times. All four coronal mass ejections are headed toward Earth.
Space weather forecasts are even more challenging than regular weather forecasts, said Dr. Leon Golub, and a coronal mass ejection is like a hurricane
: it's large and fuzzy, and doesn't always move at the same speed. Currently, the estimated arrival times are:
Wednesday, Aug. 4 – 3:00 a.m. EDT (0700 GMT on Aug. 5; aurorae not visible in daylight)
Wednesday, Aug. 4 – 1:00 p.m. EDT (1600 GMT, again the daylight issue)
Wednesday, Aug. 4 – 8:00 p.m. EDT (0000 GMT on Aug. 5)
Thursday, Aug. 5 – 2:00 a.m. EDT (0600 GMT)
Any one of these events may or may not generate an aurora. It depends on details like magnetic field orientation. If the magnetic field in the oncoming solar plasma is directed opposite Earth's magnetic field, the result could be spectacular aurorae. If the fields line up, the coronal mass ejection could slide past our planet with nary a ripple.
The Center for Astrophysics suggested these two resources:
Map of current auroral activity
Chart of proton flux (watch for the numbers to go up as each wave arrives)
Source: Harvard Smithsonian Center for Astrophyics
Related posts:
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
THE ASTRONOMY PICTURE OF THE DAY FOR 2010 April 18
Large Eruptive Prominence Imaged by STEREO
Credit: STEREO Project, NASA
Explanation: What's happened to our Sun? Last week, it produced one of the most power eruptive prominences ever seen. Pictured above, the prominence erupted in only a few hours and was captured in movie form by NASA's twin Sun-orbiting STEREO satellites. A quiescent solar prominence is a cloud of hot solar gas held above the Sun's surface by the Sun's magnetic field. Unpredictably, however, prominences may erupt, expelling hot gas into the Solar System via a Coronal Mass Ejection (CME). As pictured above, many Earths would easily fit under the expanding
ribbon of hot gas. Although somehow related to the Sun's changing magnetic field, the energy mechanism that creates and sustains a Solar prominence is still a topic of research.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
From Spaceweather.com for 2010 April 2nd
SOLAR PROMINENCE: Today, amateur astronomers around the world are monitoring a huge prominence rising over the sun's northeastern limb. It's so big,
it won't fit in the space provided. Click on the image below to see the entire arch:
Eric Roel took the picture just hours ago from his backyard observatory in Valle de Bravo, Mexico. Since then, the view has changed. Magnetic fields underpinning this magnificent structure are in a state of fairly rapid motion, pulling the plasma to and fro, offering a different profile to every observer. The whole thing could become unstable and collapse. Readers with solar telescopes are encouraged to monitor developments.
more images: from Andy Devey of Barnsley, South Yorkshire, England; from Cai-Uso Wohler of Bispingen, Germany;
From Spaceweather.com for 2010 March 24
SUNSPOT 1057: New sunspot 1057 has almost doubled in area since it first appeared on March 23. With a pair of dark cores each larger than planet Earth,
the growing active region is an easy target for amateur solar telescopes:
Rogerio Marcon took the picture on 2010 March 24th from his backyard observatory in Campinas, Brazil. The swirling magnetic fields evident in the image harbor
energy for C-class eruptions. The active region has already hurled one coronal mass ejection (CME, movie) into space and more could be in the offing. Stay tuned.
more images: from Pete Lawrence of Selsey, West Sussex, UK; from Peter Paice of Belfast, Northern Ireland; from Pavol Rapavy of Observatory Rimavska Sobota,
Slovakia; from John C McConnell of Maghaberry Northern Ireland; from Gianfranco Meregalli of Milano Italy
THE SUN ON 2010 FEBRUARY 18
New Sunspot 1049 is growing but does not yet pose a threat for strong solar flares.
Image credit: SOHO/MDI
Sunspot Number: 49
Updated 2010 Feb 17
Spotless Days
Current Stretch: 0 days
2010 total: 2 days (4%)
2009 total: 260 days (71%)
Since 2004: 772 days
Typical Solar Min: 485 days
Updated 2010 Feb 17
The Radio Sun
10.7 cm flux: 87 sfu
Updated 2010 Feb 17
GREAT WEBSITE FOR THE LATEST UPDATES AND PHOTOS OF THE SUN AT:
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Hydrogen Alpha Photo of the Sun Taken by Bill Bradley on 2009 Nov 19 Revealing Increased Solar Activity
His Website is Listed in My Astro Links Page at Left Menu
---------------------------------------------------------------------------------------------------------------------------------------------------------
From Spaceweather.com for 2009 November 3
NOT-SO-BLANK SUN: Today, the sunspot number is zero, which means the sun is blank, right? WRONG. This morning, NASA's STEREO-A spacecraft photographed sunspot 1029 seething with activity beyond the sun's western horizon:
Photo credit: STEREO Extreme Ultra Violet Telescope (195 A)
ORIGINAL ENLARGED IMAGE BELOW:
THE NUMBERS AT BOTTOM STAND FOR THE DATE - 2009 NOV 3 AT 02:45:30 UNIVERSAL TIME WHICH IS
9:45 PM EST AND 30 SECONDS ON NOVEMBER 2nd
This impressive sunspot, which rotated past the sun's western limb three days ago, does NOT add to the sunspot number because it is no longer visible from Earth. Astronomers only count spots that are on the Earth-facing side of the sun. That's how it's been done since Rudolph Wolf invented the sunspot number in 1848. In those days, only one side of the sun was visible from Earth, so the tradition was established.
Now, however, for the FIRST TIME IN THE HISTORY OF ASTRONOMY, NASA's twin STEREO spacecraft are seeing over the sun's horizon, tracking sunspots that officially "don't count." The two spacecraft are moving toward opposite sides of the sun, and by February 2011 the entire sun will be under their watchful eyes. Perhaps it is time to start thinking about a "whole sun" sunspot number. As today's image shows, the sun is not always as blank as it appears to be.
From Spaceweather.com for 2009 October 27
BIG SUNSPOT: By unleashing four C-class solar flares in the past two days, sunspot 1029 has become the most active sunspot of the year so far. Just hours ago on Oct 27, Paul Haese photographed the maelstrom from his backyard observatory in Blackwood, South Australia:
"It's a fantastic beauty," he says. "I took the picture using my Coronado SolarMax60 and a Lumenera Skynyx 2-0 digital camera."
The sunspot is growing rapidly (movie), making it an expanding target for backyard solar telescopes. If you have one, take a look!
sunspot images: from Gianluca Valentini of Rimini, Italy; from Michael Buxton of Ocean Beach, California; from Emiel Veldhuis of Zwolle, the Netherlands; from Alan Friedman of Buffalo, NY; from Cai-Uso Wohler of Bispingen, Germany; from Steve Rismiller of Milford, Ohio; from Fabio Mariuzza of Biauzzo, Italy; from J. Maciaszek, J. Stetson of South Portland, Maine; from Etienne Lecoq of Mesnil Panneville, Normandy, France; from Mike Borman of Evansville, Indiana;
From Spaceweather.com for 2009 October 25
GROWING SUNSPOT: The sun is showing signs of life. Over the weekend, sunspot 1029 emerged and it is crackling with B- and C-class solar flares. This movie from the Solar and Heliospheric Observatory (SOHO) chronicles the sunspot's rapid development from Oct. 23rd through 25th:
In Ocean Beach, California, amateur astronomer Michael Buxton made his own movie using a digital camera and backyard solar telescope: play it. "My girlfriend and I watched the magnetic fibrils around the sunspot as they surged and swirled," he says. "It was a wonderful area of activity."
The sunspot's magnetic polarity identifies it as a member of new Solar Cycle 24. If it continues to grow at this rate, sunspot 1029 could soon become the biggest sunspot of 2009. Readers with solar telescopes are encouraged to monitor developments.
sunspot images: from Alan Friedman of Buffalo, NY; from Cai-Uso Wohler of Bispingen, Germany; from Steve Rismiller of Milford, Ohio; from Fabio Mariuzza of Biauzzo, Italy; from J. Maciaszek, J. Stetson of South Portland, Maine; from Etienne Lecoq of Mesnil Panneville, Normandy, France; from Mike Borman of Evansville, Indiana; from Emiel Veldhuis of Zwolle, the Netherlands; from Vahan Yeterian of Lompoc California; from Fabio Acquarone of Genova, Liguria, Italy; from Jan Timmermans of Valkenswaard, The Netherlands;
From Spaceweather.com for 2009 September 23.
SOLAR ACTIVITY: "Finally, the sun seems to be waking up," says astrophotographer Pete Lawrence. "There is a lot going on
around new sunspot 1026. The spot's dark core is surrounded by active fibrils and a swirling magnetic filament that gives the
region a nice 3D appearance." He took this picture using a Solarscope SF70:
"Moreover," he adds, "a second sunspot has appeared, number 1027, and it is growing rapidly."
Two big sunspots in one day? That hasn't happened in more than a year. Two is not enough to end the deepest solar minimum
in a century; nevertheless, it is a welcome interruption. Readers with solar telescopes are encouraged to monitor developments.
More Images: from Chin Wei Loon of As-syams Solar Observatory, University of Malaya, Malaysia; from Adrian Guzman of San Jose, California; from Guenter Kleinschuster of Feldbach, Austria; from Vahan Yeterian of Lompoc, California; from John C McConnell of Maghaberry Northern Ireland; from Francisco A. Rodriguez of Cabreja Mountain Observatory, Canary Islands; from Peter Paice of Belfast, Northern Ireland;
THE ASTRONOMY PICTURE OF THE DAY FOR 2009 June 4
Sunspots on a Cloudy Day (2009 JUNE 2nd)
Credit & Copyright: Stefan Seip (TWAN)
Explanation: On June 2nd, clouds over Stuttgart, Germany parted to reveal what has become a relatively rare sight, spots on the Sun. In fact, the roughly 11-year solar activity cycle is still in a surprisingly deep minimum and the years 2008 and 2009 have had the lowest sunspot counts since the 1950s. Even the latest prediction is that the new cycle, Solar Cycle 24, will reach a maximum in May 2013 with a below-average sunspot count. The Solar Cycle 24 sunspots recorded here are in active region AR 1019. Previously, only two cycle 24 active regions with sunspots, AR 1018 and AR 1017, were seen in May.
New Solar Cycle Prediction
"If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78," says panel chairman Doug Biesecker of the NOAA Space Weather Prediction Center.
Right: A solar flare observed in Dec. 2006 by NOAA's GOES-13 satellite.
It is tempting to describe such a cycle as "weak" or "mild," but that could give the wrong impression.
"Even a below-average cycle is capable of producing severe space weather," points out Biesecker. "The great geomagnetic storm of 1859, for instance, occurred during a solar cycle of about the same size we’re predicting for 2013."
The 1859 storm--known as the "Carrington Event" after astronomer Richard Carrington who witnessed the instigating solar flare--electrified transmission cables, set fires in telegraph offices, and produced Northern Lights so bright that people could read newspapers by their red and green glow. A recent report by the National Academy of Sciences found that if a similar storm occurred today, it could cause $1 to 2 trillion in damages to society's high-tech infrastructure and require four to ten years for complete recovery. For comparison, Hurricane Katrina caused "only" $80 to 125 billion in damage.
BELOW: This plot of sunspot numbers shows the measured peak of the last solar cycle in BLUE to 2010 Jan 10 and the predicted peak of the Next Solar Cycle #24 in RED.
Credit: NOAA/Space Weather Prediction Center. More and Updates at: http://www.swpc.noaa.gov/SolarCycle/index.html
The latest forecast revises an earlier prediction issued in 2007. At that time, a sharply divided panel believed solar minimum would come in March 2008 followed by either a strong solar maximum in 2011 or a weak solar maximum in 2012. Competing models gave different answers, and researchers were eager for the sun to reveal which was correct.
"It turns out that none of our models were totally correct," says Dean Pesnell of the Goddard Space Flight Center, NASA's lead representative on the panel. "The sun is behaving in an unexpected and very interesting way."
Researchers have known about the solar cycle since the mid-1800s. Graphs of sunspot numbers resemble a roller coaster, going up and down with an approximately 11-year period. At first glance, it looks like a regular pattern, but predicting the peaks and valleys has proven troublesome. Cycles vary in length from about 9 to 14 years. Some peaks are high, others low. The valleys are usually brief, lasting only a couple of years, but sometimes they stretch out much longer. In the 17th century the sun plunged into a 70-year period of spotlessness known as the Maunder Minimum that still baffles scientists.
Above: Yearly-averaged sunspot numbers from 1610 to 2008. Researchers believe upcoming Solar Cycle 24 will be similar to the cycle that peaked in 1928, marked by a red arrow. Credit: NASA/MSFC
Right now, the solar cycle is in a valley--the deepest of the past century. In 2008 and 2009, the sun set Space Age records for low sunspot counts, weak solar wind, and low solar irradiance. The sun has gone more than two years without a significant solar flare.
"In our professional careers, we've never seen anything quite like it," says Pesnell. "Solar minimum has lasted far beyond the date we predicted in 2007."
In recent months, however, the sun has begun to show timorous signs of life. Small sunspots and "proto-sunspots" are popping up with increasing frequency. Enormous currents of plasma on the sun’s surface ("zonal flows") are gaining strength and slowly drifting toward the sun’s equator. Radio astronomers have detected a tiny but significant uptick in solar radio emissions. All these things are precursors of an awakening Solar Cycle 24 and form the basis for the panel's new, almost unanimous forecast.
According to the forecast, the sun should remain generally calm for at least another year. From a research point of view, that's good news because solar minimum has proven to be more interesting than anyone imagined. Low solar activity has a profound effect on Earth’s atmosphere, allowing it to cool and contract. Space junk accumulates in Earth orbit because there is less aerodynamic drag. The becalmed solar wind whips up fewer magnetic storms around Earth's poles. Cosmic rays that are normally pushed back by solar wind instead intrude on the near-Earth environment. There are other side-effects, too, that can be studied only so long as the sun remains quiet.
Meanwhile, the sun pays little heed to human committees. There could be more surprises, panelists acknowledge, and more revisions to the forecast.
"Go ahead and mark your calendar for May 2013," says Pesnell. "But use a pencil."
Author: Dr. Tony Phillips | Credit: Science@NASA
more information
Deep Solar Minimum -- (Science@NASA)
Severe Space Weather, Social and Economic Impacts -- (Science@NASA)
Living With a Star -- (Science@NASA)
NASA Heliophysics Science Mission Directorate
Explore the Entire Region of the Sun's Influence with NASA's Heliophysics Virtual Observatories
Space weather resources: NOAA Space Weather Prediction Center, Solar and Heliospheric Observatory, Spaceweather.com
NASA's Future: US Space Exploration Policy
FROM SPACEWEATHER.COM FOR 2009 APRIL 17:
22 DAYS AND COUNTING: The sun has been blank for 22 days in a row. That seems like a long time, but it's not even close to the 100-year record set in 1913 when the sun was spotless for 92 consecutive days. Can the deep solar minimum of 2009 produce a new record? Check back in 70 days for the answer.
AURORA WATCH: High-latitude sky watchers should be alert for auroras. A solar wind stream is buffeting Earth's magnetic field and causing geomagnetic activity around the poles. Sylvain Serre sends this picture from just outside the village of Salluit in Nunavik, Canada:
Photo details: Canon EOS 30D, 800 ISO, 15 sec
"I knew it was supposed to be a good night to observe the northern lights," says Serre. "So, I went with some friends and we found the sky filled with color."
NOAA forecasters estimate a 20% chance of continued geomagnetic activity during the next 24 hours. Colorful skies may be found in Scandinavia, Iceland, northern Canada and Alaska. Stay tuned for new photos.
[Previous Aprils: 2008, 2007, 2006, 2005, 2004, 2003, 2002]
THE SUN WAS STARTING TO BECOME ACTIVE - SEE THE ARTIFICIAL ECLIPSE BELOW REVEALING PROMINENCES ON MARCH 27 - (AN OCCULTING DISC REPLACES THE MOON
WHICH WON'T CREATE A REAL TOTAL SOLAR ECLIPSE FOR NYC & LI UNTIL 2079 MAY 1 (at Sunrise)
PHOTO BY BILL BRADLEY
THE ANNULAR SOLAR ECLIPSE ON 2009 JAN 26 FROM INDONESIA THROUGH A SOLAR FILTER
THE MOON IN THE CENTER WAS TOO FAR AWAY TO FULLY COVER THE SUN TO CAUSE A TOTAL SOLAR ECLIPSE
SCROLL DOWN THIS PAGE TO SEE TOTAL SOLAR ECLIPSE PHOTOS (NO FILTER USED TO SEE TOTALITY)
BIRTH OF A SUNSPOT: Two weeks ago, a sunspot was born. The event could not be seen from Earth because it happened over the sun's eastern horizon. Yet here is a snapshot of the birth:
Click to launch a 6.8 MB mpeg movie
This trick, seeing over the sun's horizon, was accomplished by NASA's STEREO mission. STEREO consists of two identical spacecraft on nearly opposite sides of the sun. STEREO-A looks over the western horizon; STEREO-B looks over the east. STEREO-B photographed the emerging active region using its onboard ultraviolet telescope.
The sunspot was a member of new Solar Cycle 24; we know this because of its high latitude where new-cycle sunspots are always born. By the time the region rotated around to face Earth, it was fading away; no dark sunspot core was visible. Without STEREO, it might have escaped attention completely.
Solar Cycle 24 is slowly gaining strength. STEREO will allow greater scrutiny of this cycle than any other in the history of solar physics. Stay tuned for more births in the months ahead.
ARTICLE ABOVE IS FROM SPACEWEATHER.COM FOR JAN 22
*****************************************************************************************************************************************************
Deep Solar Minimum (from Science@NASA)
04.01.2009
+ Play Audio | + Download Audio | + Email to a friend | + Join mailing list
April 1, 2009: The sunspot cycle is behaving a little like the stock market. Just when you think it has hit bottom, it goes even lower.
2008 was a bear. There were no sunspots observed on 266 of the year's 366 days (73%). To find a year with more blank suns, you have to go all the way back to 1913, which had 311 spotless days: plot. Prompted by these numbers, some observers suggested that the solar cycle had hit bottom in 2008.
Maybe not. Sunspot counts for 2009 have dropped even lower. As of March 31st, there were no sunspots on 78 of the year's 90 days (87%).
It adds up to one inescapable conclusion: "We're experiencing a very deep solar minimum," says solar physicist Dean Pesnell of the Goddard Space Flight Center.
"This is the quietest sun we've seen in almost a century," agrees sunspot expert David Hathaway of the Marshall Space Flight Center.
Above: The sunspot cycle from 1995 to the present. The jagged curve traces actual sunspot counts. Smooth curves are fits to the data and one forecaster's predictions of future activity. Credit: David Hathaway, NASA/MSFC. [more]
Quiet suns come along every 11 years or so. It's a natural part of the sunspot cycle, discovered by German astronomer Heinrich Schwabe in the mid-1800s. Sunspots are planet-sized islands of magnetism on the surface of the sun; they are sources of solar flares, coronal mass ejections and intense UV radiation. Plotting sunspot counts, Schwabe saw that peaks of solar activity were always followed by valleys of relative calm—a clockwork pattern that has held true for more than 200 years: plot.
The current solar minimum is part of that pattern. In fact, it's right on time. "We're due for a bit of quiet—and here it is," says Pesnell.
But is it supposed to be this quiet? In 2008, the sun set the following records:
A 50-year low in solar wind pressure: Measurements by the Ulysses spacecraft reveal a 20% drop in solar wind pressure since the mid-1990s—the lowest point since such measurements began in the 1960s. The solar wind helps keep galactic cosmic rays out of the inner solar system. With the solar wind flagging, more cosmic rays are permitted to enter, resulting in increased health hazards for astronauts. Weaker solar wind also means fewer geomagnetic storms and auroras on Earth.
A 12-year low in solar "irradiance": Careful measurements by several NASA spacecraft show that the sun's brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming, but there are some other significant side-effects: Earth's upper atmosphere is heated less by the sun and it is therefore less "puffed up." Satellites in low Earth orbit experience less atmospheric drag, extending their operational lifetimes. Unfortunately, space junk also remains longer in Earth orbit, increasing hazards to spacecraft and satellites.
Above: Space-age measurements of the total solar irradiance (brightness summed across all wavelengths). This plot, which comes from researcher C. Fröhlich, was shown by Dean Pesnell at the Fall 2008 AGU meeting during a lecture entitled "What is Solar Minimum and Why Should We Care?"
A 55-year low in solar radio emissions: After World War II, astronomers began keeping records of the sun's brightness at radio wavelengths. Records of 10.7 cm flux extend back all the way to the early 1950s. Radio telescopes are now recording the dimmest "radio sun" since 1955: plot. Some researchers believe that the lessening of radio emissions is an indication of weakness in the sun's global magnetic field. No one is certain, however, because the source of these long-monitored radio emissions is not fully understood.
All these lows have sparked a debate about whether the ongoing minimum is "weird", "extreme" or just an overdue "market correction" following a string of unusually intense solar maxima.
"Since the Space Age began in the 1950s, solar activity has been generally high," notes Hathaway. "Five of the ten most intense solar cycles on record have occurred in the last 50 years. We're just not used to this kind of deep calm."
Deep calm was fairly common a hundred years ago. The solar minima of 1901 and 1913, for instance, were even longer than the one we're experiencing now. To match those minima in terms of depth and longevity, the current minimum will have to last at least another year.
In a way, the calm is exciting, says Pesnell. "For the first time in history, we're getting to see what a deep solar minimum is really like." A fleet of spacecraft including the Solar and Heliospheric Observatory (SOHO), the twin STEREO probes, the five THEMIS probes, Hinode, ACE, Wind, TRACE, AIM, TIMED, Geotail and others are studying the sun and its effects on Earth 24/7 using technology that didn't exist 100 years ago. Their measurements of solar wind, cosmic rays, irradiance and magnetic fields show that solar minimum is much more interesting and profound than anyone expected.
Above: An artist's concept of NASA's Solar Dynamics Observatory. Bristling with advanced sensors, "SDO" is slated to launch later this year--perfect timing to study the ongoing solar minimum. [more]
Modern technology cannot, however, predict what comes next. Competing models by dozens of top solar physicists disagree, sometimes sharply, on when this solar minimum will end and how big the next solar maximum will be. Pesnell has surveyed the scientific literature and prepared a "piano plot" showing the range of predictions. The great uncertainty stems from one simple fact: No one fully understands the underlying physics of the sunspot cycle.
Pesnell believes sunspot counts will pick up again soon, "possibly by the end of the year," to be followed by a solar maximum of below-average intensity in 2012 or 2013.
But like other forecasters, he knows he could be wrong. Bull or bear? Stay tuned for updates.
Author: Dr. Tony Phillips | Credit: Science@NASA
more information
Solar Wind Loses Power, Hits 50-year Low -- (Science@NASA)
Spotless Sun: Blankest Year of the Space Age -- (Science@NASA)
NASA Heliophysics Science Mission Directorate
Explore the Entire Region of the Sun's Influence with NASA's Heliophysics Virtual Observatories
Space weather resources: NOAA Space Weather Prediction Center, Solar and Heliospheric Observatory, Spaceweather.com
NASA's Future: US Space Exploration Policy
************************************************************************************************************
SOHO celebrates 1500th comet discovery
The Kreutz-Group comet SOHO-1500 was spotted on June 25th 2008 in images taken by the LASCO C2 coronagraph. High-Res TIFF image
Animation of SOHO's 1500th comet. SOHO-1500 is located between the two white horizontal bars and the insert in the lower left shows a magnification of the area containing the comet. Click on the image for a larger animation.
It's the most successful comet catcher in history. SOHO has just reached a new milestone: It has discovered its 1500th comet, making it more successful than all the other discoverers of comets throughout history put together. Not bad for a spacecraft that was designed as a solar physics mission. SOHO's history-making discovery was made on June 25th 2008 by US-based amateur astronomer Rob Matson. This is Rob's 76th SOHO comet find.
When it comes to comet catching, the SOlar and Heliospheric Observatory has one big advantage over everybody else: its location. Situated between the Sun and the Earth, it has a privileged view of a region of space that can rarely be seen from Earth. From the surface of the planet, the space inside our orbit is largely obscured because of the daytime sky and so we only clearly see close to the Sun during an eclipse.
Roughly eighty-five percent of the SOHO discoveries, and also this one, are fragments from a once great comet that split apart in a death plunge around the Sun, probably many centuries ago. The fragments are known as the Kreutz group and now pass within 1.5 million kilometres of the Sun's surface when they return from deep space.
At this proximity, which is a near miss in celestial terms, most of the fragments are finally destroyed, evaporated by the Sun's fearsome radiation - all within the sight of SOHO's electronic eyes. One of twelve instruments, the Large Angle and Spectrometric Coronograph (LASCO) takes the pertinent images.
Of course, LASCO itself does not make the detections; that task falls to an open group of highly skilled volunteers who scan the data as soon as it is downloaded to Earth. When SOHO is transmitting to Earth, the data can be on the Internet and ready for analysis just 15 minutes after it is taken.
Enthusiasts from all over the world look at each individual image for a tiny moving speck that could be a comet. When someone believes they have found one, they submit their results to Karl Battams at the Naval Research Laboratory in Washington, DC, who checks all of SOHO's findings before submitting them to the Minor Planet Center, where the comet is catalogued and has its orbit calculated.
The wealth of comet information has value beyond mere classification. "This is allowing us to see how comets die," says Battams. When a comet constantly circles the Sun, so it loses a little more ice every time, until it eventually falls to pieces, leaving a long trail of fragments. Thanks to SOHO, astronomers now have a plethora of images showing this process. "It is a unique data set and could not have been achieved in any other way," says Battams.
All this on top of the extraordinary revelations that the solar physics mission has provided over the thirteen years it has been in space, observing the Sun and the near-Sun environment. "Catching the enormous total of comets has been an unplanned bonus," says Bernhard Fleck, ESA's SOHO Project Scientist.
Related Links
Prominence Times Four (January 9, 2009)
Hi-res TIF image (4.0M)
MPEG Movie: Large (8.8M)
Quicktime Movie: Large ( 15M), Small (1.8M)
By a fairly uncommon coincidence, STEREO (Ahead) observed four prominences that rose up and danced above the sun's surface for most a 2-day period (Dec. 30-31, 2008), each in its own quadrant. The show ended with a bang as New Year's Eve approached when the largest of the four erupted and was spun away into space. Prominences are clouds of cooler gases that are suspended above the Sun by magnetic forces, lasting from hours to days. This STEREO instrument observes the Sun in extreme UV wavelength of light of material at about 60,000 degrees C. and takes an image about every 10 minutes (which can then be run together to make a video clip).
LARGE PLUME ERUPTS ON THE SUN ON DECEMBER 24
CHRISTMAS PROMINENCE: So, you received a solar telescope for Christmas? Perfect timing. A plume of hot gas is spewing over the northeastern limb of the sun, beckoning for attention. Take a look! Photos: from James Screech of Bedford, England; from Peter Desypris of Athens, Greece; FROM SPACEWEATHER.COM FOR CHRISTMAS
News stories below are from Spaceweather.com for December 17
GIANT BREACH IN EARTH'S MAGNETIC FIELD: NASA's five THEMIS spacecraft have discovered a breach in Earth's magnetic field ten times larger than anything previously thought to exist. The size of the opening and the strange way it forms could overturn long-held ideas of space physics: full story. Already top story at SPECIAL NEWS at Left Menu
SOLAR ACTIVITY: Hours ago, something on the far side of the sun exploded and hurled a massive cloud of debris (a CME which stands for CORONAL MASS EJECTION - See Below ) over the eastern limb. Using a coronagraph to block the sun's glare, the Solar and Heliospheric Observatory (SOHO) photographed the cloud expanding into space:
NASA's Stereo-B spacecraft is stationed over the sun's eastern limb, but it was NOT taking pictures at the probable time of the eruption, so details of the blast are unknown. The CME could herald an active region (e.g., a sunspot or perhaps an unstable magnetic filament) turning to face Earth in the days ahead. Stay tuned for updates.
GREEN SOLSTICE: On Dec. 12th, a solar wind stream delivered a glancing blow to Earth's magnetic field and turned the skies above Scandinavia aurora-green: NOTE THAT THE WINTER SOLSTICE DID NOT OCCUR UNTIL DEC 21st.
Photo details: Canon EOS 1000D, 18mm, F3.5, 800 ISO, 6 sec
"Strong moonlight added a snowy highlight to the scene," says photographer Jostein Johansen of Tromsø, Norway. The solar wind stream that caused the display came from a far-northern coronal hole. Because of the hole's high latitude, the emerging stream almost missed Earth and only just brushed against our planet's magnetic field. Nevertheless, "it was a beautiful display."
On Dec. 21st, another solar wind stream will arrive, only this time it will hit Earth directly. The stream is spewing from a coronal hole that straddles the sun's equator, which puts our planet squarely in the "cross hairs." The longest night of the year could be a green one; Arctic sky watchers should be alert for auroras.
*****************************************************************************************************************
A Coronal Mass Ejection (CME) is an ejection of material from the solar corona, usually observed with a white-light coronagraph.
The ejected material is a plasma consisting primarily of electrons and protons (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entraining coronal magnetic field.
Past CORONAL MASS EJECTIONS
The FIRST detection of a CME as such was made on December 14, 1971 by R. Tousey (1973) of the Naval Research Laboratory using the 7th Orbiting Solar Observatory (OSO-7).[1] Earlier observations of coronal transients or even phenomena observed visually during solar eclipses are now understood as essentially the same thing.
The largest geomagnetic perturbation, resulting presumably from a "tobay" CME, coincided with the first-observed solar flare, in 1859. The flare was observed visually by Richard Christopher Carrington and the geomagnetic storm was observed with the recording magnetograph at Kew Gardens. The same instrument recorded a crotchet, an instantaneous perturbation, which easily be understood at the time because it predated the discovery of X-rays by Roentgen and the recognition of the ionosphere by Kennelly and Heaviside
Impact of a CME
When the ejection reaches the Earth as an ICME (Interplanetary CME), it may disrupt the Earth's magnetosphere, compressing it on the day side and extending the night-side tail. When the magnetosphere reconnects on the nightside, it creates trillions of watts of power which is directed back toward the Earth's upper atmosphere. This process can cause particularly strong aurora also known as the Northern Lights, or aurora borealis (in the Northern Hemisphere), and the Southern Lights, or aurora australis (in the Southern Hemisphere). CME events, along with solar flares, can disrupt radio transmissions, cause power outages (blackouts), and cause damage to satellites and electrical transmission lines.
Physical properties
THE CORONA NEAR SOLAR MAXIMUM ON 1999 AUG 11 - TOTAL SOLAR ECLIPSE FROM FRANCE
RADIATION IS SPREADING IN ALL DIRECTIONS. PHOTO bv Luc Viatour
THE CORONA DURING THE TOTAL SOLAR ECLIPSE ON 2006 MARCH 29 FROM SIDE, TURKEY
SHORTLY BEFORE SOLAR MINIMUM. SOLAR RADIATION IS SPREADING PRIMARILY IN THE
PLANE OF THE SUN's MAGNETIC EQUATOR. PHOTO by Ralf Künnemann
A typical CME has a three part structure consisting of a cavity of low electron density, a dense core (the prominence, which appears as a bright region on coronagraph images) embedded in this cavity, and a bright leading edge. It should be noted, however, that many CMEs are missing one of these elements, or even all three.
Most CMEs originate from active regions (groupings of sunspots associated with frequent flares). These regions have closed magnetic field lines, where the magnetic field strength is large enough to allow the containment of the plasma; the CME must open these field lines at least partially to escape from the sun. However, CMEs can also be initiated in quiet sun regions (although in many cases the quiet region was recently active). During solar minimum, CMEs form primarily in the coronal streamer belt near the solar magnetic equator. During solar maximum, CMEs originate from active regions whose latitudinal distribution is more homogeneous.
Coronal Mass Ejections range in speed from about 20 km/s to 2,700 km/s with an average speed (based on SOHO/LASCO measurements between 1996 and 2003) of 489 km/s. The average mass based on coronagraph images is 1.6 x 1015 g. Due to the two-dimensional nature of the coronagraph measurements, these values are lower limits. The frequency of ejections depends on the phase of the solar cycle: from about one every other day near solar minimum to 5-6 per day near solar maximum. These values are also lower limits because CMEs propagating away from the Earth ("backside CMEs") can usually not be detected by coronagraphs.
Current knowledge of CME kinematics indicates that the CME starts with an initial pre-acceleration phase characterised by a slow rising motion, followed by a period of rapid acceleration away from the Sun until a near-constant velocity is reached. Some "balloon" CMEs (usually the very slowest ones) lack this three-stage evolution, instead accelerating slowly and continuously throughout their flight. Even for CMEs with a well-defined acceleration stage, the pre-acceleration stage is often absent (or perhaps unobservable).
Association with other solar phenomena
Coronal Mass Ejections are often associated with other forms of solar activity, most notably:
eruptive prominence and X-Ray sigmoids
coronal dimming (long-term brightness decrease on the solar surface)
EIT and Moreton waves
coronal waves (bright fronts propagating from the location of the eruption)
post-eruptive arcades.
The association of a CME with some of those phenomena is common but not fully understood. For example, CMEs and flares were at first thought to be directly connected, with the flare driving the CME. However, only 60% of flares (M-class and stronger) are associated with CMEs.[2] Similarly, many CMEs are not associated with flares. It is now thought that CMEs and associated flares are caused by a common event (the CME peak acceleration and the flare peak radiation often coincide). In general, all of these events (including the CME) are thought to be the result of a large-scale restructuring of the magnetic field.
CME models
At first, it was thought that CMEs might be driven by the heat of an explosive flare. However, it soon became apparent that many CMEs were not associated with flares, and that even those that were often began before the flare did. Because CMEs are initiated in the solar corona (which is dominated by magnetic energy), their energy source must be magnetic. Only flares could provide enough heat energy to drive the CME, and flares get their energy from the magnetic field anyway.
Because the energy of CMEs is so high, it is unlikely that their energy could be directly driven by emerging magnetic fields in the photosphere (although this is still a possibility). Therefore, most models of CMEs assume that the energy is stored up in the coronal magnetic field over a long period of time and then suddenly released by some instability or a loss of equilibrium in the field. There is still no consensus on which of these release mechanisms is correct, and observations are not currently able to constrain these models very well.
Interplanetary CMEs
CMEs typically reach Earth one to five days after the eruption from the Sun. During their propagation, CMEs interact with the solar wind and the Interplanetary Magnetic Field (IMF). As a consequence, slow CMEs are accelerated toward the speed of the solar wind and fast CMEs are decelerated toward the speed of the solar wind. Fast CMEs (faster than about 500 km s-1) eventually drive a shock. This happens when the speed of the CME in the frame moving with the solar wind is faster than the local fast magnetosonic speed. Such shocks have been observed directly by coronagraphs[3] in the corona and are related to type II radio bursts. They are thought to form sometimes as low as 2 Rs (solar radii). They are also closely linked with the acceleration of Solar Energetic Particles.[4]
STEREO mission
On 25th October 2006, NASA launched the Solar TErrestrial RElations Observatory (STEREO), two near-identical spacecraft which form widely separated points in their orbits will produce the first stereoscopic images of CMEs and other solar activity measurements. The spacecraft will orbit the Sun at distances similar to that of the Earth, with one slightly ahead of Earth and the other trailing. Their separation will gradually increase so that after 4 years they will be almost diametrically opposite each other in orbit.[5]
In popular culture
In the novel Congo, by Michael Crichton, a CME disrupts the transmission from the Congo research team's computers to the satellites and back to Houston.
Type II radio emissions are the basis of the "Stargate" LP and CD tracks and gallery installations, recorded and exhibited by sound art group Disinformation in 1996 - see Disinformation (art and music project).
A coronal mass ejection also appears in the Stargate Atlantis episode Echoes a particularly massive one threatened to wipe out all life on the planet Lantea. The process happened three times over the last 100,000 years.
THE ARTICLE ABOVE ON CORONAL MASS EJECTIONS IS FROM WIKIPEDIA
*************************************************************************************************************************************************************
THE SUN IS NOW STARTING TO RISE EARLIER AND SETTING AFTER 5 PM
LOOK AT THE TABLE BELOW ( Aligned if You Use Mozilla Firefox)
NOTICE HOW SLIGHT THE CHANGE IS (IF ANY) FOR THE FIRST 2 WEEKS OF DECEMBER
FOR LATEST SUNSETS AND THE FIRST 2 WEEKS AFTER DEC 27 FOR LATEST SUNRISES.
AZI MEANS AZIMUTH WHICH IS THE COMPASS DIRECTION (225 IS SW, I80 IS S ,135 IS SE)
TRANSIT TIMES ARE ACTUAL SOLAR NOON FOR LONG BEACH, NY
AFTER THE TRANSIT TIME IS THE SUN'S ANGULAR ALTITUDE ABOVE THE HORIZON AND DIRECTION - DUE SOUTH (S)
Location: W 73°38'30.0", N40°35'04.0", 5m
(Longitude referred to Greenwich meridian)
Time Zone: 5h 00m west of Greenwich
DATE BEG of SUNRISE TRANSIT SUNSET END of
TWILIGHT TIME AZI TIME ALT TIME AZI TWILIGHT
2008 Dec 01 (Mon) 05:22 06:59 119 11:44 28S 16:28 241 18:05 = 6:05 PM
2008 Dec 02 (Tue) 05:23 07:00 119 11:44 27S 16:28 241 18:05
2008 Dec 03 (Wed) 05:24 07:01 119 11:45 27S 16:28 241 18:05
2008 Dec 04 (Thu) 05:25 07:02 119 11:45 27S 16:28 241 18:05
2008 Dec 05 (Fri) 05:25 07:03 119 11:45 27S 16:27 241 18:05
2008 Dec 06 (Sat) 05:26 07:04 120 11:46 27S 16:27 240 18:05
2008 Dec 07 (Sun) 05:27 07:05 120 11:46 27S 16:27 240 18:05
2008 Dec 08 (Mon) 05:28 07:06 120 11:47 27S 16:27 240 18:05
2008 Dec 09 (Tue) 05:29 07:07 120 11:47 27S 16:27 240 18:06
2008 Dec 10 (Wed) 05:29 07:08 120 11:48 26S 16:28 240 18:06
2008 Dec 11 (Thu) 05:30 07:08 120 11:48 26S 16:28 240 18:06
2008 Dec 12 (Fri) 05:31 07:09 120 11:49 26S 16:28 240 18:06
2008 Dec 13 (Sat) 05:32 07:10 120 11:49 26S 16:28 240 18:06
2008 Dec 14 (Sun) 05:32 07:11 120 11:50 26S 16:28 239 18:07
2008 Dec 15 (Mon) 05:33 07:11 121 11:50 26S 16:29 239 18:07
2008 Dec 16 (Tue) 05:33 07:12 121 11:50 26S 16:29 239 18:07
2008 Dec 17 (Wed) 05:34 07:13 121 11:51 26S 16:29 239 18:08
2008 Dec 18 (Thu) 05:35 07:13 121 11:51 26S 16:30 239 18:08
2008 Dec 19 (Fri) 05:35 07:14 121 11:52 26S 16:30 239 18:09
2008 Dec 20 (Sat) 05:36 07:14 121 11:52 26S 16:30 239 18:09
2008 Dec 21 (Sun) 05:36 07:15 121 11:53 26S 16:31 239 18:10
2008 Dec 22 (Mon) 05:37 07:15 121 11:53 26S 16:32 239 18:10
2008 Dec 23 (Tue) 05:37 07:16 121 11:54 26S 16:32 239 18:11
2008 Dec 24 (Wed) 05:38 07:16 121 11:54 26S 16:33 239 18:11
2008 Dec 25 (Thu) 05:38 07:17 121 11:55 26S 16:33 239 18:12
2008 Dec 26 (Fri) 05:38 07:17 121 11:55 26S 16:34 239 18:12
2008 Dec 27 (Sat) 05:39 07:17 121 11:56 26S 16:35 239 18:13
2008 Dec 28 (Sun) 05:39 07:18 120 11:56 26S 16:35 240 18:14
2008 Dec 29 (Mon) 05:39 07:18 120 11:57 26S 16:36 240 18:14
2008 Dec 30 (Tue) 05:40 07:18 120 11:57 26S 16:37 240 18:15
2008 Dec 31 (Wed) 05:40 07:18 120 11:58 26S 16:38 240 18:16
2009 Jan 01 (Thu) 05:40 07:18 120 11:58 26S 16:39 240 18:17
2009 Jan 02 (Fri) 05:40 07:18 120 11:59 27S 16:39 240 18:17
2009 Jan 03 (Sat) 05:40 07:18 120 11:59 27S 16:40 240 18:18
2009 Jan 04 (Sun) 05:41 07:18 120 12:00 27S 16:41 240 18:19
2009 Jan 05 (Mon) 05:41 07:18 120 12:00 27S 16:42 241 18:20
2009 Jan 06 (Tue) 05:41 07:18 119 12:01 27S 16:43 241 18:21
2009 Jan 07 (Wed) 05:41 07:18 119 12:01 27S 16:44 241 18:22
2009 Jan 08 (Thu) 05:41 07:18 119 12:01 27S 16:45 241 18:22
2009 Jan 09 (Fri) 05:41 07:18 119 12:02 27S 16:46 241 18:23
2009 Jan 10 (Sat) 05:41 07:18 119 12:02 28S 16:47 241 18:24
2009 Jan 11 (Sun) 05:40 07:17 118 12:03 28S 16:48 242 18:25
2009 Jan 12 (Mon) 05:40 07:17 118 12:03 28S 16:49 242 18:26
2009 Jan 13 (Tue) 05:40 07:17 118 12:03 28S 16:50 242 18:27
2009 Jan 14 (Wed) 05:40 07:16 118 12:04 28S 16:51 242 18:28
2009 Jan 15 (Thu) 05:40 07:16 117 12:04 28S 16:53 243 18:29
2009 Jan 16 (Fri) 05:39 07:16 117 12:04 29S 16:54 243 18:30
2009 Jan 17 (Sat) 05:39 07:15 117 12:05 29S 16:55 243 18:31
2009 Jan 18 (Sun) 05:39 07:15 117 12:05 29S 16:56 244 18:32
2009 Jan 19 (Mon) 05:38 07:14 116 12:05 29S 16:57 244 18:33
2009 Jan 20 (Tue) 05:38 07:14 116 12:06 29S 16:58 244 18:34
2009 Jan 21 (Wed) 05:38 07:13 116 12:06 30S 16:59 244 18:35
2009 Jan 22 (Thu) 05:37 07:12 115 12:06 30S 17:01 245 18:36
2009 Jan 23 (Fri) 05:37 07:12 115 12:07 30S 17:02 245 18:37
2009 Jan 24 (Sat) 05:36 07:11 115 12:07 30S 17:03 245 18:38
2009 Jan 25 (Sun) 05:35 07:10 114 12:07 31S 17:04 246 18:39
2009 Jan 26 (Mon) 05:35 07:09 114 12:07 31S 17:05 246 18:40
2009 Jan 27 (Tue) 05:34 07:09 114 12:07 31S 17:07 246 18:41
2009 Jan 28 (Wed) 05:34 07:08 113 12:08 31S 17:08 247 18:42
2009 Jan 29 (Thu) 05:33 07:07 113 12:08 32S 17:09 247 18:43
2009 Jan 30 (Fri) 05:32 07:06 113 12:08 32S 17:10 248 18:44
2009 Jan 31 (Sat) 05:31 07:05 112 12:08 32S 17:12 248 18:45
2009 Feb 01 (Sun) 05:31 07:04 112 12:08 33S 17:13 248 18:46
2009 Feb 17 (Tue) 05:14 06:45 105 12:09 38S 17:32 255 19:04
2009 Feb 18 (Wed) 05:13 06:44 104 12:08 38S 17:33 256 19:05
2009 Feb 19 (Thu) 05:11 06:43 104 12:08 38S 17:35 256 19:06
2009 Feb 20 (Fri) 05:10 06:41 104 12:08 39S 17:36 257 19:07
2009 Feb 21 (Sat) 05:09 06:40 103 12:08 39S 17:37 257 19:08
2009 Feb 22 (Sun) 05:08 06:38 103 12:08 39S 17:38 258 19:09
2009 Feb 23 (Mon) 05:06 06:37 102 12:08 40S 17:39 258 19:10
2009 Feb 24 (Tue) 05:05 06:36 102 12:08 40S 17:40 259 19:11
2009 Feb 25 (Wed) 05:03 06:34 101 12:08 41S 17:42 259 19:13
2009 Feb 26 (Thu) 05:02 06:33 101 12:07 41S 17:43 260 19:14
2009 Feb 27 (Fri) 05:00 06:31 100 12:07 41S 17:44 260 19:15
2009 Feb 28 (Sat) 04:59 06:30 100 12:07 42S 17:45 261 19:16
2009 Mar 01 (Sun) 04:58 06:28 99 12:07 42S 17:46 261 19:17
2009 Mar 02 (Mon) 04:56 06:27 99 12:07 42S 17:47 262 19:18
2009 Mar 03 (Tue) 04:54 06:25 98 12:06 43S 17:48 262 19:19
2009 Mar 04 (Wed) 04:53 06:23 98 12:06 43S 17:50 263 19:20
2009 Mar 05 (Thu) 04:51 06:22 97 12:06 44S 17:51 263 19:21
2009 Mar 06 (Fri) 04:50 06:20 97 12:06 44S 17:52 264 19:23
2009 Mar 07 (Sat) 04:48 06:19 96 12:06 44S 17:53 264 19:24
2009 Mar 08 (Sun) 04:47 06:17 96 12:05 45S 17:54 265 19:25
2009 Mar 09 (Mon) 04:45 06:16 95 12:05 45S 17:55 265 19:26
2009 Mar 10 (Tue) 04:43 06:14 94 12:05 46S 17:56 266 19:27
2009 Mar 11 (Wed) 04:42 06:12 94 12:04 46S 17:57 266 19:28
2009 Mar 12 (Thu) 04:40 06:11 93 12:04 46S 17:58 267 19:29
2009 Mar 13 (Fri) 04:38 06:09 93 12:04 47S 17:59 267 19:30
2009 Mar 14 (Sat) 04:37 06:08 92 12:04 47S 18:00 268 19:32
2009 Mar 15 (Sun) 04:35 06:06 92 12:03 48S 18:02 268 19:33
2009 Mar 16 (Mon) 04:33 06:04 91 12:03 48S 18:03 269 19:34
2009 Mar 17 (Tue) 04:31 06:03 91 12:03 48S 18:04 269 19:35
2009 Mar 18 (Wed) 04:30 06:01 90 12:03 49S 18:05 270 19:36
THE SUN HAD A NEW SPOT ON THANKSGIVING 2008
BUT SO FAR IN DECEMBER AND JANUARY THE SUN HAS BEEN SPOTLESS
THANKSGIVING SUN: This morning Greg Piepol of Rockville, Maryland, looked through the eyepiece of his backyard solar telescope and observed a very curious sunspot:
"Happy Thanksgiving!" says Piepol. "I must have been thinking about dinner because when I did a double-take the turkey was gone." The real Thanksgiving sun is pictured here. A new sunspot is forming near the center of the sun's disk but it has not yet formed a dark turkey-core. Stay tuned for updates.
more images: from Andy Yeung of Hong Kong; from Stephen Ames of Hodgenville, Kentucky
From Spaceweather.com for Nov 27
********************************************************************************************************************************************************
CORONAL HOLE: Japan's Hinode spacecraft is monitoring a dark hole on the sun-- a coronal hole:
Coronal holes are places in the sun's atmosphere where the magnetic field opens up and allows solar wind to escape. In images taken by X-ray telescopes, such as the one Hinode uses, coronal holes appear dark because the hot glowing gas which would otherwise fill them has spilled out in the solar wind. A stream of gas flowing from this particular hole is heading for Earth. High-latitude sky watchers should be alert for auroras when it arrives on Nov. 25th or 26th.
From Spaceweather.com for Nov 24
*******************************************************************************************************************************
THE SUNSPOTS MENTIONED IN THE ARTICLES BELOW ARE NO LONGER VISIBLE
The Sun Shows Signs of Life
Nov. 7, 2008: After two-plus years of few sunspots, even fewer solar flares, and a generally eerie calm, the sun is finally showing signs of life.
"I think solar minimum is behind us," says sunspot forecaster David Hathaway of the NASA Marshall Space Flight Center.
His statement is prompted by an October flurry of sunspots. "Last month we counted five sunspot groups," he says. That may not sound like much, but in a year with record-low numbers of sunspots and long stretches of utter spotlessness, five is significant. "This represents a real increase in solar activity."
Above: New-cycle sunspot group 1007 emerges on Halloween and marches across the face of the sun over a four-day period in early November 2008. Credit: the Solar and Heliospheric Observatory (SOHO).
Even more significant is the fact that four of the five sunspot groups belonged to Solar Cycle 24, the long-awaited next installment of the sun's 11-year solar cycle. "October was the first time we've seen sunspots from new Solar Cycle 24 outnumbering spots from old Solar Cycle 23. It's a good sign that the new cycle is taking off."
Old Solar Cycle 23 peaked in 2000 and has since decayed to low levels. Meanwhile, new Solar Cycle 24 has struggled to get started. 2008 is a year of overlap with both cycles weakly active at the same time. From January to September, the sun produced a total of 22 sunspot groups; 82% of them belonged to old Cycle 23. October added five more; but this time 80% belonged to Cycle 24. The tables have turned.
At first glance, old- and new-cycle sunspots look the same, but they are not. To tell the difference, solar physicists check two things: a sunspot's heliographic latitude and its magnetic polarity. (1) New-cycle sunspots always appear at high latitude, while old-cycle spots cluster around the sun's equator. (2) The magnetic polarity of new-cycle spots is reversed compared to old-cycle spots. Four of October's five sunspot groups satisfied these two criteria for membership in Solar Cycle 24.
The biggest of the new-cycle spots emerged at the end of the month on Halloween. Numbered 1007, or "double-oh seven" for short, the sunspot had two dark cores each wider than Earth connected by active magnetic filaments thousands of kilometers long. Amateur astronomer Alan Friedman took this picture from his backyard observatory in Buffalo, New York:
On Nov. 3rd and again on Nov. 4th, double-oh seven unleashed a series of B-class solar flares. Although B-flares are considered minor, the explosions made themselves felt on Earth. X-rays bathed the dayside of our planet and sent waves of ionization rippling through the atmosphere over Europe. Hams monitoring VLF radio beacons noticed strange "fades" and "surges" caused by the sudden ionospheric disturbances.
Hathaway tamps down the excitement: "We're still years away from solar maximum and, in the meantime, the sun is going to have some more quiet stretches." Even with its flurry of sunspots, the October sun was mostly blank, with zero sunspots on 20 of the month's 31 days.
But it's a start. Stay tuned for solar activity.
GREAT PROMINENCE: "The sun left two gifts on my doorstep this morning," says Alan Friedman of Buffalo, New York. "There was a gorgeous solar prominence and a glorious warm November day that allowed me to observe it in shirtsleeves!" This was the view through his backyard solar telescope:
Other observers saw it, too: Stephen Ames of Hodgenville, Kentucky, called it "a real WOWser!" Jan Timmermans of the Netherlands measured the prominence and found it surging "four times higher than Earth itself. It was huge." John Boyd of Santa Barbara, California, said "it was the biggest prominence I've seen in a long time. I'm glad the sun is getting active again."
Indeed it is. The month of October brought four new-cycle sunspots, doubling the total of the previous nine months. For the first time in 2008, new-cycle active regions are outnumbering their old-cycle counterparts. Solar Cycle 24 is definitely picking up steam and this fiery prominence may be a further sign of things to come.
Readers, if you have a solar telescope, take a look at the increasingly active sun BUT YOU MUST USE THE PROPER SOLAR FILTER FOR DIRECT VIEWING!! If you use projection of the sun onto a white screen a filter is not necessary.
From www.Spaceweather.com for 2008 Nov 7
********************************************************************************************************************************************************
NEW SUNSPOT # 1008 HAS FORMED. SEE DETAILED PHOTO WITH ENLARGED INSET BELOW:
Photographed by David Leong from Hong Kong on 2008 November 13
Taken with LS60TCaK and DMK cameras.
Posted on www.Spaceweather.com
SOHO = THE SOLAR AND HELIOSPHERIC OBSERVATORY at http://sohowww.nascom.nasa.gov/
****************************************************************************************************************************************************
FINALLY THE SUN HAS A COUPLE OF SUNSPOTS BEGINNING SOLAR CYCLE #1005 . THE SUN HAD BEEN DEVOID OF SUNSPOTS FOR MUCH OF 2008 - LOWEST NUMBER FOR ABOUT A HALF CENTURY
2008 Oct 12
DETAILS BELOW ABOUT THE TWIN SATELLITES WHICH COMPRISE THE STEREO MISSION
THE STEREO TWIN SATELLITE MISSION
From Wikipedia, the free encyclopedia
STEREO
One of two STEREO spacecraft
Organization
Major contractors
Mission type
Satellite of
Launch date
Launch vehicle
Mission duration
Mass
Johns Hopkins University Applied Physics Laboratory
00:52 GMT
Delta II 7925
2 years minimum
approximately 1142 pounds (642 kg) each
This article is about the spacecraft and the mission. For other uses of the term "Stereo", see Stereo (disambiguation).
STEREO (Solar TErrestrial RElations Observatory) is a solar observation mission which was launched on 26 October 2006 at 00:52 GMT.[1] Two nearly identical spacecraft were launched into orbits that cause them to (respectively) pull further ahead of and fall gradually behind the earth. This will enable stereoscopic imaging of the Sun and solar phenomena, such as Coronal Mass Ejections.
Mission profile
Launch of the STEREO spacecraft atop a Delta II (7925-10L) rocket, 00:52 GMT on 26 October 2006
This was 3.5 years ago
The two STEREO spacecraft were launched at 0052 UTC on October 26, 2006 from Launch Pad 17B at the Cape Canaveral Air Force Station in Florida on a Delta II 7925-10L launcher into highly elliptical geocentric orbits. The apogee reached the Moon's orbit. On December 15, 2006, on the fifth orbit, the pair swung by the moon for a gravitational slingshot. Because the two spacecraft were in slightly different orbits, the "ahead" (A) spacecraft was ejected to a heliocentric orbit inside Earth's orbit while the "behind" (B) spacecraft remained temporarily in a high earth orbit. The B spacecraft encountered the Moon again on the same orbital revolution on January 21, 2007, ejecting it from earth orbit in the opposite direction from spacecraft A. Spacecraft B entered a heliocentric orbit outside the Earth's orbit. Spacecraft A will take 347 days to complete one revolution of the sun and Spacecraft B will take 387 days. The A spacecraft/sun/earth angle will increase at 21.650 deg/year. The B spacecraft/sun/earth angle will change -21.999 degrees per year.
Because the A spacecraft is going faster than B, they are separating from each other and A is orbiting closer to the sun than B. This means stereoscopic pairs of images will soon be impossible for human eyes to fuse, which is a STEREO paradox. At the end of March 2007, the stereoscopic parallax was 1/50, but in June it is already 1/25. "Ideal" stereoscopic parallax is 1/30 and below 1/10 fusion is difficult even for experts. Already the east and west edges of the sun are becoming difficult, because one eye is seeing further around the sun than the other. Fortunately, the middle of the solar disc and up towards the poles will be fused stereoscopically after the edges become impossible. The A images, from the satellite closer to the sun, are bigger than B. Magnification must be corrected before stereoscopic fusion by human eyes is possible. Of course the mission does not depend on 3D vision to be useful and mathematical reduction of STEREO image data will continue.
Science Instrumentation
SEE THE MOVIE OF THIS LUNAR TRANSIT SHOT FROM STEREO B FROM WHICH THE PICTURE ABOVE WAS TAKEN. GO TO:
http://science.nasa.gov/headlines/y2007/12mar_stereoeclipse.htm?list39638 AND CLICK ON THE MEDIUM or LARGE FORMAT
An lunar transit of the sun captured during calibration of Stereo B's Ultra Violet imaging cameras.
Each of the spacecraft carries cameras, particle experiments and radio detectors in four instrument packages:
Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) - SECCHI has five cameras: an extreme ultraviolet imager and two white-light coronagraphs (collectively known as the Sun Centered Instrument Package or SCIP), which image the solar disk and the inner and outer corona, plus two heliospheric imagers (called the HI), which image the space between Sun and Earth. The purpose of SECCHI is to study the 3-D evolution of Coronal Mass Ejections through their full journey from the Sun's surface through the corona and interplanetary medium to their impact at Earth.[2] [3]
In-situ Measurements of Particles and CME Transients (IMPACT) - IMPACT will study energetic particles, the three-dimensional distribution of solar wind electrons and interplanetary magnetic field.[2] [4]
PLAsma and SupraThermal Ion Composition (PLASTIC) - PLASTIC will study the plasma characteristics of protons, alpha particles and heavy ions.[2]
STEREO/WAVES (SWAVES) - SWAVES is a radio burst tracker that will study radio disturbances traveling from the Sun to the orbit of Earth.[2]
Spacecraft Subsystems
STEREO's onboard computer systems are based on the Integrated Electronics Module (IEM), a device that combines core avionics in a single box. Each single-string spacecraft carries two 25 megahertz RAD6000 CPUs: one for Command/Data-handling, and one for Guidance-and-Control. Both are radiation hardened RAD6000 processors, based on IBM POWER CPUs (predecessor of the PowerPC chip found in older Macintoshes). The computers, slow by current personal computer standards, are typical for the radiation requirements needed on the STEREO mission.
For data storage, each spacecraft carries a solid state recorder able to store up to one gigabyte each. Its main processor collects and stores on the recorder images and other data from STEREO's instruments, which can then be sent back to Earth.
A MUST SEE VIDEO BELOW
OF A LUNAR TRANSIT
FROM STEREO-B
The STEREO Space Probes in a Goddard Center Cleanroom
One of the first images of the Sun taken by STEREO
The Moon passing in front of the Sun from STEREO-B, February 25, 2007 (See the movie of the transit)
The Sun's South Pole. Material can be seen erupting off the sun in the lower right side of the image.
See also
SOHO, solar observatory launched in 1995, still operational.
Ulysses probe, 1990 mission, still operational.
Advanced Composition Explorer (ACE), launched 1997, still operational.
Transition Region and Coronal Explorer (TRACE), launched 1998, still operational.
References
^ "NASA Launch Schedule". NASA Missions (September 20, 2006). Retrieved on September 20, 2006.
^ a b c d "STEREO Spacecraft & Instruments". NASA Missions (March 8, 2006). Retrieved on May 30, 2006.
^ Howard R. A., Moses J. D., Socker D. G., Dere K. P., Cook J. W. (2002). "Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)". Solar Variabilit and Solar Physics Missions Advances in Space Research 29 (12): 2017–2026.
^ Luhmann J. G., Curtis D. W., Lin R. P., Larson D, Schroeder P., Cummings A., Mewaldt R. A., Stone E. C., Davis A., von Rosenvinge T., Acuna M. H., Rearnes D., Ng C., Ogilvie K., Mueller-Mellin R., Kunow H., Mason G. M., Wiedenbeck M., Sauvaud A., Aoustin C., Louarn P., Dandouras J., Korth A., Bothmer V., Vasyliunas V., Sanderson T., Marsden R. G., Russell C. T., Gosling J. T., Bougeret J. L., McComas D. J., Linker J. A., Riley P., Odstrcil D., Pizzo V. J., Gombosi T., DeZeeuw D., Gombosi T., DeZeeuw D., Kecskemety K. (2005). "IMPACT: Science goals and firsts with STEREO". Solar Encounter, Solar-B and Stereo Advances in Space Research 36 (8): 1534–1543.
^ "Honeywell To Provide Miniature Inertial Measurement Units For STEREO Spacecraft". Web. Honeywell International, Inc.. Retrieved on 2006-10-25.
STEREO spacecraft to image solar blasts in glorious 3-D, New Scientist December 9, 2005
Orbit simulations, on the NASA site
External links
*********************************************************************************************************************************************************