... The Sun Changes . ... This recent picture was taken in a very specific red color called Hydrogen-Alpha . Dark spots that might appear on the image are usually sunspots , dark magnetic depressions that are slightly cooler than the rest of the Sun's surface. ... Over the next few years the average number of sunspots and plages will increase until "Solar Maximum" occurs in 2001. ... Публикации с ключевыми словами: Sun - sunspot - Солнечная активность - Солнечные пятна - Флоккул . ... Дыра в Солнце . ...

... 2008 September 24 . Active Region 1002 on an Unusually Quiet Sun . ... Explanation: Why has the Sun been so quiet recently? ... Our Sun has shown few active regions -- that house even fewer associated sunspots -- for over a year now, and such a period of relative calm is quite unusual. ... Visible above, this region, dubbed Active Region 1002 (AR 1002), was imaged in ultraviolet light yesterday by the SOHO spacecraft , which co-orbits the Sun near the Earth. ... About APOD | ...

Galaxies are diffuse objects which are imaged against a background of finite brightness and noise. Galaxies which have the maximum contrast with respect to this background are the ones that are first discovered. ... These galaxies have been missed to date but active surveys for them are underway. ... In this page we present several examples of these newly discovered Low Surface Brightness galaxies as well as examples of high surface brightness galaxies. ...

... The active time at each angular bin is the sum over frames of the active time contributions from all CCD pixels, within the node-specific telemetry window, which overlap the surface of the bin. ... The active time, per frame, of a normal pixel is the full frame integration time multiplied by the node-specific fractional exposure; bad pixels contribute no active time. ... If an event is rejected for this reason only, then its pixels remain normal in the exposure map. ...