139P/Väisälä–Oterma

For other comets also discovered by Yrjö Väisälä, see Comet Väisälä.

139P/Väisälä–Oterma is a periodic comet in the Solar System. When it was discovered in 1939 it was not recognized as a comet and designated as asteroid 1939 TN.

139P/Väisälä–Oterma

Discovery
Discovered by	Yrjö Väisälä Liisi Oterma
Discovery date	October 7, 1939
Designations
Alternative designations	1939 TN; 1998 WG22
Orbital characteristics
Epoch	March 6, 2006
Aphelion	5.62 AU
Perihelion	3.402 AU
Semi-major axis	4.511 AU
Eccentricity	0.2458
Orbital period	9.58 a
Inclination	2.3296°
Last perihelion	December 10, 2017 April 19, 2008
Next perihelion	2027-Jul-23[1]