First STEREO Image of Sun

This will be the first of many fullimages of the sun that captures the whole sun at the same time.  They are setting up to operate for eight years.Most important is that we will now acquire a detailed tracking of this specificperiod of sun spot activity which has already begun and will continue throughthe eight years.

In the event, go to the links tolook at the full movie as shown.

First Ever STEREO Images of the Entire Sun

February 6, 2011: It's official: The sun is a sphere.

On Feb. 6th, NASA's twin STEREO probes moved into position on oppositesides of the sun, and they are now beaming back uninterrupted images of theentire star—front and back.

"For the first time ever, we can watch solar activity in its full3-dimensional glory," says Angelos Vourlidas, a member of the STEREOscience team at the Naval Research Lab in Washington, DC.

NASA released a 'first light' 3D movie on, naturally, Super BowlSun-day:

The solar sphere as observed by STEREO and the Solar DynamicsObservatory on January 31, 2011. Because the STEREO separation was stillslightly less than 180o at that time, a narrow gap on the far side of theSun has been interpolated to simulate the full 360o view. The gap andquality of farside imaging will improve even more in the days and weeks ahead.[YouTube video] [full42MB movie]

"This is a big moment in solar physics," says Vourlidas."STEREO has revealed the sun as it really is--a sphere of hot plasma andintricately woven magnetic fields."

Each STEREO probe photographs half of the star and beams the images toEarth. Researchers combine the two views to create a sphere. These aren't justregular pictures, however. STEREO's telescopes are tuned to four wavelengths ofextreme ultraviolet radiation selected to trace key aspects of solar activitysuch as flares, tsunamis and magnetic filaments. Nothing escapes theirattention.

An artist's concept of STEREO surrounding the sun. [more]

"With data like these, we can fly around the sun to see what'shappening over the horizon—without ever leaving our desks," says STEREOprogram scientist Lika Guhathakurta at NASA headquarters. "I expect greatadvances in theoretical solar physics and space weather forecasting."

Consider the following: In the past, an active sunspot could emerge onthe far side of the sun completely hidden from Earth. Then, the sun's rotationcould turn that region toward our planet, spitting flares and clouds of plasma,with little warning.

"Not anymore," says Bill Murtagh, a senior forecaster atNOAA's Space WeatherPrediction Centerin Boulder, Colorado. "Farside active regions canno longer take us by surprise. Thanks to STEREO, we know they're coming."

NOAA is already using 3D STEREO models of CMEs (billion-ton clouds ofplasma ejected by the sun) to improve space weather forecasts for airlines,power companies, satellite operators, and other customers. The full sun view shouldimprove those forecasts even more.

The forecasting benefits aren't limited to Earth.

"With this nice global model, we can now track solar stormsheading toward other planets, too," points out Guhathakurta. "This isimportant for NASA missions to Mercury, Mars, asteroids … you name it."

Observing solar storms from two points of view has allowed forecastersto made 3D models of advancing coronal mass ejections (CMEs), improvingpredictions of Earth impacts. Credit: NOAA/SWPC [movie]

NASA has been building toward this moment since Oct. 2006 when theSTEREO probes left Earth, split up, and headed for positions on opposite sidesof the sun (movie). Feb.6, 2011, was the date of "opposition"—i.e., when STEREO-A and -B were180 degrees apart, each looking down on a different hemisphere. NASA'sEarth-orbiting Solar Dynamics Observatory is also monitoring the sun 24/7.Working together, the STEREO-SDO fleet should be able to image the entire globefor the next 8 years.

The new view could reveal connections previously overlooked. Forinstance, researchers have long suspected that solar activity can "goglobal," with eruptions on opposite sides of the sun triggering andfeeding off of one another. Now they can actually study the phenomenon.The GreatEruption of August 2010 engulfed about 2/3rd of the stellar surfacewith dozens of mutually interacting flares, shock waves, and reverberatingfilaments. Much of the action was hidden from Earth, but plainly visible to theSTEREO-SDO fleet.

"There are many fundamental puzzles underlying solaractivity," says Vourlidas. "By monitoring the whole sun, we can findthe missing pieces."

Researchers say these first-look images are just a hint of what's tocome. Movies with higher resolution and more action will be released in theweeks ahead as more data are processed. Stay tuned!

Author: Dr.Tony Phillips | Credit: Science@NASA

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