| C/1943 W1 (van Gent–Peltier–Daimaca) | |
| Discoverer: | Hendrik van Gent Leslie C. Peltier Victor Daimaca |
| Discovery Date: | 27 November 1943 |
| Designations: | 1943g 1944 I |
| Epoch: | 3 December 1943 (JD 2431061.5) |
| Observation Arc: | 10 days |
| Obs: | 12 |
| Aphelion: | 3,589.46 AU |
| Perihelion: | 0.874 AU |
| Semimajor: | 1,795.17 AU |
| Eccentricity: | 0.9995 |
| Period: | 76,061.65 years |
| Inclination: | 136.183° |
| Asc Node: | 58.630° |
| Arg Peri: | 33.092° |
| Tjup: | –0.834 |
| Earth Moid: | 0.0335 AU |
| Jupiter Moid: | 0.8510 AU |
| Magnitude: | 6.0 (1943 apparition) |
| Last P: | 12 January 1944 |
Comet van Gent–Peltier–Daimaca, formally designated as C/1943 W1, is a non-periodic comet with a rather peculiar discovery. It was independently discovered by four astronomers, however the established system of naming comets by the International Astronomical Union only recognizes the names of the first three people who observed it.
It was first observed by Dutch astronomer Hendrik van Gent on November 27, 1943 as a diffuse magnitude 9.0 object in the constellation Puppis. However, due to the ongoing Second World War, the report of his discovery took longer than usual that various other astronomers had enough time to make independent discoveries. By the time it reached magnitude 6.0, it was then rediscovered by astronomers Leslie C. Peltier, Victor Daimaca, and Geoffrey Francis Kelloway on December 16, 17, and 19 respectively, however they were not identified as the same object as van Gent's comet until its orbit was calculated in December 22. As established by the IAU, only the names of the first three observers are recognized as the comet's co-discoverers.
The very small MOID with Earth has led various astronomers since 1948 to think that this comet is a potential parent body of a yet to be identified meteor shower. Analysis of past observations from 1925 and 1935 initially identified this hypothetical meteor shower as the Alpha Monocerotids, where it reaches its peak on November 21 and 22 each year. Follow-up studies from more recent observations however has concluded that the aforementioned meteor shower wasn't related to C/1943 W1 itself, but rather a still unidentified short-period comet yet to be discovered.