40P/Vaisala (0040P)
Type: Periodic
Perihelion date: 11 November 2025
Perihelion distance (q): 1.8
Aphelion distance (Q) : 8.1
Period (years): 11.1
Eccentricity (e): 0.63
Inclination (i): 11.6
JPL orbit diagram
COBS lightcurve
Atlas
Yrjö Väisälä (University of Turku, Finland) discovered this comet on photographs
exposed for the study of minor planets. It was first found on 8 February 1939, and
was given the asteroidal designation of 1939 CB. Shortly thereafter, pre-discovery
images were found on plates taken at the same observatory on 19 January. Väisälä
obtained additional confirmation and identified the object as a comet on plates
exposed on 14 March. At that time he described it as diffuse, without a central
condensation or nucleus, and about magnitude 15. From the available positions, Liisi
Oterma was able to compute an elliptical orbit which had a period of about 10 years, a
perihelion date of 26 April 1939, and a perihelion distance of 1.75 AU.
The comet experienced four close approaches to Earth and two close approaches to
Jupiter during the 20th century. It makes one close approach to Earth and one close
approach to Jupiter during the 21st century.
•
0.77 AU from Earth on 18 March 1918
•
0.89 AU from Earth on 1 March 1939
•
0.98 AU from Earth on 22 February 1960
•
0.41 AU from Jupiter on 31 December 1961, increased perihelion distance from
1.74 AU to 1.87 AU, increased orbital period from 10.46 to 11.28 years
•
1.00 AU from Jupiter on 22 September 1973, decreased perihelion distance from
1.87 AU to 1.80 AU, decreased orbital period from 11.28 to 10.88 years
•
0.92 AU from Earth on 2 March 1993
•
0.90 AU from Jupiter on 26 March 2024, increased perihelion distance from 1.820
AU to 1.824 AU, decreased orbital period from 10.98 to 10.99 years
•
0.88 AU from Earth on 2070 March 24
Observations (VEMag = visual equivalent magnitude)
Date
10x10 mag
Error
VEmag
Coma '