... The choice of which type of electricity is called "positive" and which "negative" was made around 1750 by Ben Franklin, early American scientist and man of many talents (the stamp on the left commemorates his role as first US postmaster--and colonial postmaster before that). ... Franklin knew of two types of electric charge, depending on the material one rubbed. ... Later, when electric batteries were discovered, scientists naturally assigned the direction of the flow of current to be from (+) to (-...

The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

Подписка на рассылку обзоров astro-ph на Subscribe.Ru . ... Предыдущий выпуск (N335) . ... Обсудить на форуме Scientific.RU . ... Подписка на рассылку обзоров на Subscribe.Ru . Обзоры препринтов astro-ph . ... Собственно обзоры препринтов. ... Ранее обзоры также были на Астронете и на Scientific.Ru . ... АНКи доступны на Астронете , а с 2006 по 2008 г. также на сайте Элементы.Ру . ... Ранее они также размещались на сайте Астронет и в архиве моих обозрений (кодировка KOI8) на сайте Scientific.Ru . ...

This page shows which observing modes are available with which correlator and gives a brief description of the observing modes.. available; . ... WAPP . ... ALFA . ... Calibration mode that scans 4 times across the calibrator, forming a spider shape. ... Calibration mode that scans twice across the calibrator, forming a cross shape. ... This is the standard spectral-line single-pixel observing mode. ... A Calibration mode used by the Galactic ALFA surveys to calibration the G-ALFA HI Spectrometer. ...

... As of October 1, 2009, the global rate for the STIS NUV-MAMA dark current has still been occasionally reaching values as high as 13500 counts/s. This high dark current will force use of a signficantly smaller buffer time than would be otherwise needed, and in many cases may push the count rate high enough to make time-tag observations impractical. ... However, we instead found for the NUV MAMA detector an initial global dark rate of between 9000 and 18000 counts/s (a mean of 0.013 counts/s/pixel). ...

Solar Flare Origin - critical analysis" Lev Pusti'lnik We analyze current approach to solar flare origin in 3 aspects: a. Pre-flare equilibrium state of current-magnetic structure above active region and its evolution to flare state, b. Possible reasons of stability loss with transition of system in flare state c. Flare energy release in turbulent current sheet and particle acceleration in this system. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . ... Current telescope status . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... News Latest News News Archive Newsletter Quarterly Status Report . ... How to use SAS SAS Workshops SAS Version Changes Download and Install SAS Science Simulator (SciSim) . Archive, Pipeline & Catalogues XMM-Newton Science Archive Pipeline Processing System Observation Data Status Time Correlation Fix Serendipitous Source Catalogue OM Serendipitous Source Catalogue Slew Survey Catal