Comet Hyakutake in March 1996
January 18, 2010
I had my first look at Comet Hyakutake on the morning of March 8, 1996 from rural eastern Kansas, and began photographing it on March 16. During this time, as Hyakutake rapidly approached its March 25th pass by Earth and subsequent perihelion passage on the May 1, it underwent an incredible transformation as it grew brighter and larger. This was not a particularly dust-rich comet; Hyakutake’s primary feature was its long ion tail -- a shorter dust tail was also visible. The top photo shows the comet as it appeared to the camera on the morning of March 21. On this morning, the photographic length of the ion tail was 22 degrees, but to emphasize the structure in the tails close to the comet’s coma, a telephoto lens was used and records only 11 degrees of the ion tail. Clicking on the image will allow a rollover of your cursor to yield comet and star field details.
The bottom photo was taken just over 26 hours after the comet’s closest approach to Earth, on the bone-chilling morning of March 26. It shows the ion tail stretching an amazing 60 degrees from near Kochab (Beta Ursae Minoris), all the way into the cluster of stars making up part of the constellation of Coma Berenices. A disconnection is clearly visible halfway down the tail. As with the first image, clicking on this one will allow a cursor rollover for details. Thanks to Stephen J. O’Meara, Gary Kronk’s Cometography, JPL’s interactive orbital diagram for comet Hyakutake and Dan Green at the Harvard-Smithsonian Center for Astrophysics for invaluable information.
Photo details of top photo: a 10 minute exposure (hand guided with the camera piggyback on an old Tasco equatorial refractor); centered at 10:15 UT; with a 135 mm NIKKOR lens; at f/2.8; on Fujicolor Super G 400 film; taken from Linn County, Kansas.
Bottom photo: an 11 minute exposure (hand guided); centered at 09:40 UT; with a 24 mm NIKKOR lens; at f/4; on Fujicolor Super G 400 film, taken from Carroll County in northwest Missouri.
See also the Astronomy Picture of the Day for December 16, 2009