46P/Wirtanen

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**46P/Wirtanen**
Discovery
Discovered by:	Carl A. Wirtanen
Discovery date:	January 17, 1948
Alternate designations:	1961 IV; 1960m; 1967 XIV; 1967k; 1974 XI; 1974i; 1986 VI; 1985q; 1991 XVI; 1991s; 46P/1948 A1; 1947 XIII; 1948b; 46P/1954 R2; 1954 XI; 1954j
Orbital characteristics ^A
Epoch:	September 3, 2002 (JDT 2452520.5)
Aphelion distance:	5.129946 AU
Perihelion distance:	1.0587602 AU
Semi-major axis:	3.0943529 AU
Eccentricity:	0.6578412
Orbital period:	5.44 a
Inclination:	11.73813°
Last perihelion:	August 26, 2002
Next perihelion (predicted):	February 2, 2008

46P/Wirtanen is a small short-periodic comet with a current orbital period of 5.4 years. It was the original target for close investigation by the Rosetta spacecraft, planned by the European Space Agency. It belongs to the Jupiter family of comets, all of which have aphelia between 5 and 6 AU. Its diameter is estimated at 1.4 km.

[edit] Discovery

46P/Wirtanen was discovered photographically on January 17, 1948 by the American astronomer Carl A. Wirtanen. The plate was exposed on January 15 during a stellar proper motion survey for the Lick Observatory. Due to a limit number of initial observations, it took more than a year to recognize this object as a short-periodic comet.