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Posts Tagged ‘sunspots’

NJIT’s New Solar Telescope Unveils The Complex Dynamics Of Sunspots’ Dark Cores


NJIT’s Big Bear Solar Observatory

NJIT’s Big Bear Solar Observatory

Groundbreaking images of the Sun captured by scientists at NJIT’s Big Bear Solar Observatory (BBSO) give a first-ever detailed view of the interior structure of umbrae – the dark patches in the center of sunspots – revealing dynamic magnetic fields responsible for the plumes of plasma that emerge as bright dots interrupting their darkness. Their research is being presented this week at the first Triennial Earth-Sun Summit meeting between the American Astronomical Society’s Solar Physics Division and the American Geophysical Union’s Space Physics and Aeronomy section in Indianapolis, Ind.

The high-resolution images, taken through the observatory’s New Solar Telescope (NST), show the atmosphere above the umbrae to be finely structured, consisting of hot plasma intermixed with cool plasma jets as wide as 100 kilometers.

“We would describe these plasma flows as oscillating cool jets piercing the hot atmosphere. Until now, we didn’t know they existed. While we have known for a long time that sunspots oscillate – moderate resolution telescopes show us dark shadows, or penumbral waves, moving across the umbra toward the edge of a sunspot – we can now begin to understand the underlying dynamics,” said Vasyl Yurchyshyn, a research professor of physics at NJIT and the lead author of two recent journal articles based on the NST observations.

Link To Full Story

A&A Press Release – No Evidence Of Planetary Influence On Solar Activity

September 6, 2013 Leave a comment

Image Credit: Swedish Solar Telescope at the Roque de los Muchachos Observatory

Image Credit: Swedish Solar Telescope at the Roque de los Muchachos Observatory

In 2012, Astronomy & Astrophysics published a statistical study of the isotopic records of solar activity, in which Abreu et al. claimed that there is evidence of planetary influence on solar activity. A&A is publishing a new analysis of these isotopic data by Cameron and Schüssler. It corrects technical errors in the statistical tests performed by Abreu et al. They find no evidence of any planetary effect on solar activity.

The Sun is a magnetically active star. Its activity manifests itself as dark sunspots and bright faculae on its visible surface, as well as violent mass ejections and the acceleration of high-energy particles resulting from the release of magnetic energy in its outer atmosphere. The frequency with which these phenomena occur varies in a somewhat irregular activity cycle of about 11 years, during which the global magnetic field of the Sun reverses. The solar magnetic field and the activity cycle originate in a self-excited dynamo mechanism based upon convective flows and rotation in the outer third of the solar radius.

Systematic observations of sunspots since the beginning of the 17th century indicate that solar activity also varies on longer timescales, including periods of very low activity, such as the so-called Maunder minimum between 1640 and 1700.

Full Story: http://www.aanda.org/index.php?option=com_content&task=view&id=966&Itemid=277

Link Found Between Cold European Winters And Solar Activity

August 23, 2012 2 comments

CREDIT: Warburg, via Wikimedia Commons

Scientists have long suspected that the Sun’s 11-year cycle influences climate of certain regions on Earth. Yet records of average, seasonal temperatures do not date back far enough to confirm any patterns. Now, armed with a unique proxy, an international team of researchers show that unusually cold winters in Central Europe are related to low solar activity — when sunspot numbers are minimal. The freezing of Germany’s largest river, the Rhine, is the key.

From the early 19th through mid-20th centuries, riverboat men used the Rhine for cargo transport. And so docks along the river have annual records of when ice clogged the waterway and stymied shipping. The scientists used these easily-accessible documents, as well as other additional historical accounts, to determine the number of freezing episodes since 1780.

Mapping the freezing episodes against the solar activity’s 11-year cycle — a cycle of the Sun’s varying magnetic strength and thus total radiation output — Sirocko and his colleagues determined that ten of the fourteen freezes occurred during years when the Sun had minimal sunspots. Using statistical methods, the scientists calculated that there is a 99 percent chance that extremely cold Central European winters and low solar activity are inherently linked.

Full Story: http://www.agu.org/news/press/pr_archives/2012/2012-39.shtml

Big Sunspot Unleashes X-flare & CME


Solar activity is now high. Big sunspot AR1429, which emerged on March 2nd, is crackling with strong flares. The strongest so far, an X1-class eruption, occured just ths morning, March 5th at 0413 UT. NASA’s Solar Dynamics Observatory recorded the extreme ultraviolet flash:

The explosion also hurled a bright coronal mass ejection (CME) into space: SOHO movie. The expanding cloud will probably deliver a glancing blow to Earth’s magnetic field on March 6th or 7th. (Stay tuned for updates on this possibility as more data arrive.) High-latitude sky watchers should be alert for auroras in the nights ahead.

Auroras alerts: textphone.

Full Story: http://spaceweather.com/archive.php?view=1&day=05&month=03&year=2012

‘Cool’ Gas May Form & Strengthen Sunspots

January 31, 2012 Leave a comment

Hydrogen molecules may act as a kind of energy sink that strengthens the magnetic grip that causes sunspots, according to scientists from Hawaii and New Mexico using a new infrared instrument on an old telescope.

“We think that molecular hydrogen plays an important role in the formation and evolution of sunspots,” said Dr. Sarah Jaeggli, a recent University of Hawaii at Manoa graduate whose doctoral research formed a key element of the new findings. She conducted the research with Drs. Haosheng Lin, also from the University of Hawaii at Manoa, and Han Uitenbroek of the National Solar Observatory in Sunspot, NM. Jaeggli now is a postdoctoral researcher in the solar group at Montana State University. Their work is published in the Feb. 1, 2012, issue of The Astrophysical Journal.

Full Story: http://www.nso.edu/press/FIRS/

Forecasting Sunspots Breakthrough

August 26, 2011 Leave a comment

Imagine forecasting a hurricane in Miami weeks before the storm was even a swirl of clouds off the coast of Africa—or predicting a tornado in Kansas from the flutter of a butterfly’s wing in Texas. These are the kind of forecasts meteorologists can only dream about.

Could the dream come true? A new study by Stanford researchers suggests that such forecasts may one day be possible—not on Earth, but on the sun.

Full Story: http://www.nasa.gov/mission_pages/sunearth/news/sunspot-breakthru.html

New Method Detects Emerging Sunspots Inside the Sun

August 19, 2011 Leave a comment

New Method Detects Emerging Sunspots Inside the Sun

A full disk image of the Sun showing the sunspot group in AR11158 after emergence, observed by SDO/HMI. Courtesy of NASA/SDO and the HMI science teams.

The first clear detection of emerging sunspot regions prior to any indication of the region in magnetograms was published in Science on 19 August 2011.

Sunspots, dark features in the solar photosphere with strong magnetic field, have been observed for more than 400 years. They are the most visible components of regions where solar flares and coronal mass ejections (CMEs) occur, and these eruptive events may cause power outages and interruptions of telecommunication and navigation services on the Earth. Although it is widely believed that sunspot regions are generated in the deep solar interior, the detection of these regions before they emerge from the convection zone into the photosphere has remained undetected until now.

Full Story: http://hmi.stanford.edu/Press/18Aug2011/