According to a NASA Web site: The MDI (Michelson Doppler Imager) images shown here are taken in the continuum near the NiI 6768 Angstroms line. The most prominent solar features are the sunspots on the solar photosphere. This is very much how the Sun looks like in the visible range of the spectrum (for example, looking at it using special 'eclipse' glasses: Remember, do not ever look directly at the Sun!).
-- Richard Langley On Wed, 3 Jan 2001, Gordon Uber wrote: >John, > >I think that the SOHO images are updated at least once a day. The latest >sunspot image was taken at 10:16 UT today. The satellite is in a >zero-gravity region between the earth and the sun, so I would think that it >is always on our side of the sun, although I don't know for certain. The >sun's rotation period is a function of latitude, 25 days at the equator, 33 >days at 75 degrees (Skilling and Richardson, 1947). > >SOHO images are at >http://sohowww.nascom.nasa.gov/data/realtime-update.html > >Gordon > > >At 07:14 AM 1/3/01 -0700, you wrote: >> >Hello all: >> >>I just looked at the SOHO solar satellite photos of the sunspots and noticed >>that the spots were different from the ones I saw on Christmas morning. >>Could it be that SOHO was on the opposite side of the sun when the picture >>was taken? Or maybe the sun's rotation since Christmass brought the sun's >>farside into view. >> >>If an earthboud observer wants to see both sides of the sun, how long will >>he have to wait between observations until the sun rotates 180 degrees? >>What is the rotation rate of the sun? >> >>John Carmichael >>Tucson Arizona > >Gordon Uber [EMAIL PROTECTED] San Diego, California USA >Webmaster: Clocks and Time: http://www.ubr.com/clocks > > =============================================================================== Richard B. Langley E-mail: [EMAIL PROTECTED] Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 University of New Brunswick Fax: +1 506 453-4943 Fredericton, N.B., Canada E3B 5A3 Fredericton? Where's that? See: http://www.city.fredericton.nb.ca/ ===============================================================================
