active region


Also found in: Acronyms.

active region

[′ak·tiv ′rē·jən]
(astronomy)
A localized, transient, nonuniform region on the sun's surface, penetrating well down into the lower chromosphere.
(electronics)
The region in which amplifying, rectifying, light emitting, or other dynamic action occurs in a semiconductor device.
References in periodicals archive ?
If the sunspots are relatively small, said Canfield, then sigmoidal active regions are about four times as likely to erupt as nonsigmoidal ones.
Initially, ground-based observations could not identify this flare's origin, but the Yohkoh spacecraft determined that it came from a large active region behind the eastern limb of the Sun (see the bottom left image).
Probing the heating of the Sun's active region loops can help us to better understand the physical mechanisms for more energetic events which can impinge on the Earth's environment," she noted.
Because of the tiny difference in travel time, sound waves that pass through magnetically active regions are slightly out of step with waves that don't.
Moreover, when an active region on the near side rotates out of view, SWAN continues to detect an enhanced ultraviolet glow from the hydrogen gas.
Working closely with the DTI to ensure high-quality data is available to the industry will benefit all E&P companies working in this highly active region.
Planetary scientists do not yet know how soon after the appearance of an S pattern an active region will erupt.
from the office is expected to take a place of business in the active region, all relevant actors integrates, manages the active region and the board, the necessary abstimmungenmit performs the office of rural areas and the ministry of agriculture, environment and rural areas and promoter advises and projects developed.
WASHINGTON (CyHAN)- The Sun burst out with a curling spray of plasma from an active region just coming into view (Dec.
Our new LED, however, which has a radically re-designed active region, namely a polarization-matched active region, tackles this issue and brings LEDs closer to being able to operate efficiently at high current densities," Schubert said.
Using Surveyor images to count the number of small craters, an indicator of how long ago a volcanically active region last erupted, Hartmann finds that some places on Mars spewed lava within the past 100 million years.
Contract notice: External regional management for the active region alster country for the years 2015-2022.

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