Dave Bell wrote: > WOW! Those are some great images... > > What are the LASCO instruments? Obviously the large central disk is an > occulting disk, allowing the corona to be photographed; I assume the > smaller central circle is the true diameter of the Sun. The LASCO C3 image > contains a lot of starfield background, so I suppose we could place the > solar image on a starchart, given the date and time of the image. Any idea > what the horizontal line artifact through the brightest star is? We know > that Saturn is in the opposite part of the sky this year!!
The LASCO (Large Angle Spectrometric Coronagraph) instrument is designed to observe the solar corona (the very faint outer atmosphere of the Sun). From the Earth's surface this is only visible during a total solar eclipse but from space it is easily visible if you block the Sun's disk with an appropriately sized disk. The bright object left of the Sun in the LASCO C3 image is Mercury and the horizontal line appears to be an instrumental artefact. With the aid of a star atlas or a PC planetarium program you can easily recognize some of the brighter stars of Sagittarius in the background and if you would look tomorrow or a few days later you will notice that both the Sun as Mercury have moved with respect to these stars. ======================================================== * Robert H. van Gent * Tel/Fax: 00-31-30-2720269 * * Zaagmolenkade 50 * * * 3515 AE Utrecht * E-mail: [EMAIL PROTECTED] * * The Netherlands * * ******************************************************** * Homepage: http://www.phys.uu.nl/~vgent/homepage.htm * ========================================================
