Comet Arend–Roland

C/1956 R1 (Arend–Roland)
(Great Comet of 1957)
Comet Arend-Roland photographed from the Palomar Observatory on 27 April 1957
Discovery
Discovered bySylvain Arend
Georges Roland
Discovery siteUccle Obs, Belgium
Discovery date6 November 1956
Designations
1957h
1956 III
Orbital characteristics
Epoch9 July 1957 (JD 2436028.5)
Observation arc497 days (1.36 days)
Number of
observations
57
Orbit typeOort cloud / Hyperbolic
Perihelion0.31604 AU
Eccentricity1.000199
Inclination119.94°
215.86°
Argument of
periapsis
308.77°
Last perihelion8 April 1957
Next perihelionejection
Earth MOID0.239 AU
Jupiter MOID1.610 AU
Physical characteristics
Mean radius
1.58 km (0.98 mi)
Comet total
magnitude
(M1)
5.4
–0.5
(1957 apparition)

Comet Arend–Roland was discovered on November 6, 1956, by Belgian astronomers Sylvain Arend and Georges Roland on photographic plates. As the eighth comet found in 1956, it was named Arend–Roland 1956h after its discoverers. Because it was the third comet to pass through perihelion during 1957, it was then renamed 1957 III. Finally, it received the standard IAU designation C/1956 R1 (Arend–Roland), with the "C/" indicating that it was a non-periodic comet and the "R1" showing that it was the first comet reported as discovered in the half-month designated by "R". The last is equivalent to the period September 1–15.