August 2, 2014

05.03.11: A New Breed of Sundog?

A Solar Halo…(Photo by Author).

NASA’s Solar Dynamics Observatory is well on the path to producing some ground-breaking solar science this Solar Cycle #24, and that trend started the minute it left the launch pad. On February 11th, 2010, SDO lifted off atop an Atlas V rocket, and gave viewers a memorable sight. [Read more...]

03.03.11: The Riddle of the Blank Sun: Solved?

A spotless Sol… (Photo by Author).

   Researchers At the Indian Institute of Science and Education and the Harvard-Smithsonian Center for Astrophysics may have shed light on an enduring mystery from the past decade. In an article due to be published today in Nature, Dibyendu Nandi and co-author Andre Munoz-Jaramillo have come up with convincing evidence as to why the past solar minimum of 2008-09 was such a persistent one. During this minimum, over 600 spotless days occurred, the most since the great minimum of 1913. As a result, the outer magnetic sheath of the sun that we reside in shrunk, the Earth’s upper atmosphere cooled due to lower ultraviolet levels and contracted, and an increase of cosmic ray activity was seen in the inner solar system. This subsequently affected the usual drag that is induced on satellites, slowing down the rate of orbital decay and causing a buildup of space junk… just what’s up with our nearest star?

   Now, researchers have built a model of the solar interior that fits a description of what has actually occurred; and the trouble started back at the peak of cycle #23 with a speeding up of the “Great Conveyor Belt” of plasma in the suns interior. This magnetic dynamo sub-ducts sunspot activity towards the poles, only to have them “well up” as these conveyors turn in opposite directions in both hemispheres. Paradoxically, a slowing down leads to a relaxing and expansion of the belt, allowing magnetic activity to surface; speeding up meant the activity never had a chance to surface. Sunspot activity usually begins at high latitudes at the beginning of a cycle, a hallmark that the new cycle is indeed underway. As the sunspot cycle progresses, sunspot activity tends to progress to lower latitudes. The model suggested by Nandi and Munoz is built on the buoyant evolution of sunspots versus the interplay of the magnetic dynamo and the meridional flows in the solar interior. This theory may also explain two other lingering mysteries; why are sunspots never seen at polar solar latitudes? Does the sun have longer cycles juxtaposed over the known 11 year one, such as the 70 year cycle that occurred in the 17th century known as the Maunder Minimum?

   Researchers will soon have a chance to put all of these models to the test. NASA’s Solar Dynamics Observatory is on solar vigil, and the twin STEREO spacecraft have reached a vantage point giving scientists 360° coverage of the Sun. Solar cycle #24 will see the sun scrutinized as never before. Even today, two new sunspot groups have emerged, and a large prominence looking like an acacia tree can be seen on the limb of the sun from Astroguyz HQ via our trusty PST… the approaching 2013-14 solar maximum may prove to mark a renaissance in solar science.      

 

26.05.10: SDO and the Coronal Rain.

Coronal Rain as imaged by SDO. (Credit: NASA/SDO).

Coronal Rain as imaged by SDO. (Credit: NASA/SDO).

  

   NASA’s Solar Dynamics Observatory continues to astound. Launched earlier this year, SDO is already providing insight into key solar mysteries. One long standing mystery has been the action of what’s termed “coronal rain.” This long documented phenomenon is caused by super heated blobs of plasma in-falling back to the fiery surface of the Sun. But until now, no one could adequately model the slowing down of this sinking material. It was as if an unidentified medium existed, “cushioning” the fall of the coronal rain. In a recent news conference, SDO scientists revealed a key culprit; an underlying area of hot gas. What makes SDO standout from previous solar observatories is its acute temperature sensing technology. Utilizing its ultraviolet Atmospheric Imaging Assembly (AIA), SDO can probe the outer layers of the Sun’s atmosphere as never before. The picture emerging is of relatively cool (60,000 K) plasma falling through hotter material standing between 1,000,000 K and 2,200,000 K.

All of this portends to a future understanding of our Sun in intimate detail. As Solar Cycle #24 gets underway, Platforms like SDO will study our nearest star in unprecedented resolution. As Dick Fisher, head of NASA’s Heliophysics Division stated; “I’ve never seen images like this…” Keep em’ coming!

23.04.10-SDO Unveiled.

(Credit: NASA/SDO).

(Credit: NASA/SDO).

An SDO Original!

    Cool images Alert: NASA’s recently launched Solar Dynamics Observatory (SDO) has released some fairly mind-blowing pics and videos this week. The video below is but a small sampling of the capabilities showcased by this Sun-monitoring spacecraft. “We’ve seen prominences before, but not like this!” states Alan Title of Lockheed Martin. SDO was launched on February 11th, 2010 and studies the Sun from a polar inclined geosynchronous orbit. Equipped with high definition cameras and a 4096x 4096 –pixel array, you haven’t seen the Sun the way SDO has revealed it. Part of NASA’s Living With a Star program, SDO will provide a continuum in solar astronomy started by the ESA’s SOHO satellite in the 1990’s. One can only hope that SDO’s data will be as easily accessible and provide real time access to the public as SOHO has done. Not only will SDO have the capability to monitor the Sun in ultraviolet and extreme ultraviolet, but it also possesses an Atmospheric Imaging Assembly (AIA) and a Helioseismic and Magnetic Imager. But beyond pretty pictures, SDO also promises to give us a unique insight into the inner workings of our Sun. And with sunspot cycle #24 just gearing up, this capability may have come none too soon!