<P> Hyakutake is a long - period comet . Before its most recent passage through the Solar System, its orbital period was about 17,000 years, but the gravitational perturbation of the giant planets has increased this period to 70,000 years . </P> <P> The comet was discovered on 31 January 1996, by Yuji Hyakutake, an amateur astronomer from southern Japan . He had been searching for comets for years and had moved to Kagoshima Prefecture partly for the dark skies in nearby rural areas . He was using a powerful set of binoculars with 150 mm (6 in) objective lenses to scan the skies on the night of the discovery . </P> <P> This comet was actually the second Comet Hyakutake; Hyakutake had discovered comet C / 1995 Y1 several weeks earlier . While re-observing his first comet (which never became visible to the naked eye) and the surrounding patch of sky, Hyakutake was surprised to find another comet in almost the same position as the first had been . Hardly believing a second discovery so soon after the first, Hyakutake reported his observation to the National Astronomical Observatory of Japan the following morning . Later that day, the discovery was confirmed by independent observations . </P> <P> At the time of its discovery, the comet was shining at magnitude 11.0 and had a coma approximately 2.5 arcminutes across . It was approximately 2 astronomical units (AU) from the Sun . Later, a pre-discovery image of the comet was found on a photograph taken on January 1, when the comet was about 2.4 AU from the Sun and had a magnitude of 13.3 . </P>

When was the last time hyakutake was seen