Comet C/1996 B2 Hyakutake on 04-07-96 ===================================== Here are my last three pictures of Hyakutake. In the night from April 7th to April 8th I observed the comet together with Wolfgang Howurek somewhere between Niederleis and Grafensulz in Lower Austria/Europe. Humidity was high and near the horizon there was some dust in the air, but above stars could be seen down to 5.5 mag. The comet could be seen as a "needle", about 8 degrees long, two degrees northeast of the star Algol in Perseus. Venus was very bright (-4.4 mag), standing near to the Pleijades. The wide-angle photo shows the scene as it could be seen with the naked eye. The camera I used was my YASHICA TL-Electro which I mounted piggy-back on my Meade 8" f/10 telescope for guiding, using a 10mm-crosshair eyepiece. The comet didnīt move much during the exposures. The film I used was a Fuji SuperHG 1600 ASA for keeping the exposure times short. Description of the individual photos: 1. The comet using a 205mm telephoto lens: --------------------------------------- Exposure start: 18h15 UT, exposure time: 15 minutes. The field of this photo measures about 6x7 degrees. By comparing this photo to earlier photos taken with the same lens, some differences were obvious: The coma of the comet became much smaller (18 arcmins compared to 32 arcmins earlier) and moved slower, due to the greater distance from the earth. But the tail became far brighter and richer in contrast. Actually two different tail can be spotted: A diffuse, wide tail (perhaps the dust tail) and on top of it a smaller but brighter, more focussed tail, which can be traced over a longer distance and which is perhaps a plasma tail. 2. The comet using a 50mm standard lens: ------------------------------------- Exposure start: 19h40 UT, exposure time: 11 minutes. With the naked eye the comet's tail could only be traced until the Perseus star association (near to the center of the picture), but on this photo it is about 2 1/2 times as long, measuring more than 20 degrees. The slightly brighter star left of the coma is Algol, Beta Persei. On the right side under the coma the galactic cluster M34 can be seen as diffuse spot. The bightest star in the picture (near the upper left corner) is Capella, Alpha Aurigae. On it's right side the short trail of a meteor can be seen, which I didn't even notice while taking the picture. 3. The comet in a 24mm wide-angle lens: ------------------------------------ Exposure start: 20h30 UT, exposure time: 5 minutes. It needed three tries to get this photos, because an aeroplane circled just over the comet during the first two exposures. On the bottom the horizon can be seen with some light trails of nearby villages (the camera was guided for the stars). Above them there is the dust layer into wich the comet dived only a short time after the exposure. The bright spot on the left side in the dust is Venus, and under it the Pleijades. The milky way crosses the field of view, in it the constellations (from left to right) of Auriga, Perseus and Cassiopeia can be spotted. In that night the comet wasnīt anymore as impressive as during the nights when it was closest to the earth, but it was still quite a showpiece in the night sky. Clear skies, Walter Koprolin. e-mail: koprolin@venus.ast.univie.ac.at If anyone wants to publish any of my pictures in any form, he should contact me FIRST via e-mail.