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Posts Tagged ‘SOHO’

Comet ISON’S Dramatic Final Hours


A new analysis of data from the ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft has revealed that comet 2012/S1 (ISON) stopped producing dust and gas shortly before it raced past the Sun and disintegrated.

When comet ISON was discovered in the autumn of 2012, astronomers hoped that it would eventually light up the night sky to become a “comet of the century”. Orbital analysis showed that the sungrazing intruder from the outer reaches of the Solar System would pass only 1.2 million kilometres above the Sun’s visible surface on 28 November 2013.

Based on its early brightness, the comet promised to be a unique research object and, should it survive its flyby of the Sun, a stunning celestial phenomenon in the weeks preceding Christmas. However, it soon became clear that these hopes and expectations would not be met.

Link To Full Story

Bright Comet Dives Into Radiation Storm

March 14, 2012 Leave a comment

A bright comet is diving into the sun. It was discovered just last week by SOHO’s SWAN instrument, so it has been named “Comet SWAN.” The comet’s death plunge ( or “swan dive”) comes just as the sun has unleashed a strong flare and radiation storm around Earth. SOHO images of the comet are confused to some degree by energetic protons striking the camera.

Full Story: http://spaceweather.com/archive.php?view=1&day=14&month=03&year=2012

Using Many Instruments to Track a Comet

December 13, 2011 Leave a comment

In 16 years of data observations, the Solar Heliophysics Observatory (SOHO) — a joint European Space Agency and NASA mission –- made an unexpected claim for fame: the sighting of new comets at an alarming rate. SOHO has spotted over 2100 comets, most of which are from what’s known as the Kreutz family, which graze the solar atmosphere where they usually evaporate completely.

But on December 2, 2011, the discovery of a new Kreutz-family comet was announced. This comet was found the old-fashioned way: from the ground. Australian astronomer Terry Lovejoy spotted the comet, making this the first time a Kreutz comet has been found through a ground-based telescope since the 1970’s. The comet has been designated C/2011 W3 (Lovejoy).

Discovering a comet before it moves into view of space-based telescopes, gives scientists the opportunity to prepare the telescopes for the best possible observations. Indeed, since comet Lovejoy was visible from the ground, scientists have high hopes that this might be an exceptionally bright comet, making it all the easier to view and study. (Some Kreutz comets –- such as Ikeya-Seki in 1965 — are so bright they can be seen with the naked eye in the daytime, though this is extremely rare.)

Full Story: http://www.nasa.gov/mission_pages/sunearth/news/track-comet.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/