Discovery date: January 31, 1996
Also known as: The Great Comet of 1996
Peak magnitude: 0.0
Aphelion: 3410 AU (510 billion kilometres or 317 billion miles)
Perihelion: 0.2302 AU (34.44 million kilometres or 21.40 million miles)
Semi-major axis: 1700 AU (254 billion kilometres or 158 billion miles)
Eccentricity: 0.9998946
Orbital period: 70,000 years (estimate)
Inclination: 124.92246 degrees
Last perihelion: May 1, 1996
Next perihelion: 72000 (estimate)
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| Comet Hyakutake photgraphed on March 25, 1996 (E. Kolmhofer, H. Raab - Johannes-Kepler-Observatory, Linz, Austria - http://www.sternwarte.at) |
Comet Hyakutake is also known the Great Comet of 1996.
Discovered on January 31, 1996 by Japanese amateur astronomer while using 25×150 binoculars.
Apparent magnitude at discovery was +11.0. The comet was 2 AU from the Sun, beyond the orbit of Mars, and exhibited a small coma.
On March 25th, Hyakutake passed only 0.1 AU (14.96 million kilometres or 9.30 million miles) from the Earth. In the previous 100 years only four comets have passed closer.
At the time Comet Hale-Bopp had recently been discovered and was touted as a potential “Great Comet” in 1997. The discovery of Hyakutake threw the possibility of second spectacular Comet into the mix.
Reached naked eye visibility in early March 1996.
As it then approach the Earth, Hyakutake brightened significantly with its tail growing in length.
At closest approach to Earth, the comet reached magnitude 0.0 with a tail stretching up to 80 degrees in length. Even the coma was 2 degrees in diameter, 4 times the diameter of the full Moon.
Hyakutake was moving so rapidly across the night sky at this time that its movement could be detected against the stars in just a few minutes. It appeared close to the North Pole Star and consequently circumpolar (visible all night) from northern hemisphere based observers.
The comet had a notably bluish-green colour, which was noticeable even to the naked eye.
SInce Hyakutake was at its brightest for only a few days, it did not have the time to capture the public imagination in the same way that Comet Hale–Bopp did the following year.
Because of unfavourable weather conditions, many observers (particular European) missed the chance to see the comet at its peak.
Hyakutake reached perihelion on May 1, 1996 but was too close to the Sun to be easily seen.
After its perihelion passage, Hyakutake faded rapidly and was no longer a naked-eye target by June.
The last known observation of the comet was on November 2, 1996.
It has been calculated that Hyakutake passed through the inner Solar System approximately 17,000 years ago. Changes to its orbit during the 1996 passage resulting from gas-giant gravitational interactions means that it will not return to the inner Solar System for approximately 70,000 years.
