C/1913 Y1 (Delavan)
Comet Delavan, formally designated as C/1913 Y1, is a non-periodic comet discovered by astronomer Pablo T. Delavan on from the La Plata Observatory in Argentina on 18 December 1913.
The comet was last seen on 19 September 1915. It is one of 19 comets used in the original sample by Jan Oort for his hypothesis regarding the origin of long-period comets in 1950.