C/1999 T1 (McNaught–Hartley) is a near-parabolic long-period comet, discovered by Robert H. McNaught and Malcolm Hartley at the Siding Spring Observatory in 1999.
Observations Comet McNaught–Hartley was a magnitude 15 object upon discovery on October 7, 1999. Gas emissions were measured in x-ray light by the Chandra observatory (alongside C/1999 S4 (LINEAR)) between 8–14 January 2001. Observations of its coma between January 26 and February 5, 2001 show that the nucleus has a rotation period between 1 and 10 days.
Exploration
Research published in 2004 found that the Ulysses spacecraft had likely detected ions from the comet tail of C/1999 T1. This was the spacecraft's second encounter with a comet tail, after Comet Hyakutake in 1996.
See also Comet McNaught
References
External links C/1999 T1 at the JPL Small-Body Database