C/1893 N1 (Rordame–Quénisset)
Hyperbolic comet independently reported by Rordame and Quénisset in 1893.
Comet Rordame–Quénisset (modern designation C/1893 N1) is a hyperbolic comet that could be seen without a telescope in 1893. Its discovery was independently reported by Alfred Rordame and Ferdinand Quénisset, but several other astronomers had already spotted it before either of them made their reports.
At the time of discovery, the comet was a 3rd-magnitude object in the constellation Lynx. The actual first discoverers are unknown, though Rordame and Quénisset were the first to formally report it, on 8 and 9 July 1893, respectively. Later it emerged that amateur astronomers J. Miller and C. Johnson had observed it from Alta, Iowa, about two to three hours before Rordame notified Lewis A. Swift. Across the Atlantic, Mario Roso de Luna saw it from Logrosan, Spain on 4 July, but did not recognize it as a new comet until orbital calculations in August 1893 confirmed it was the same object. The earliest known prediscovery observation came from William E. Sperra, who recorded the comet a dozen times from Randolph, Ohio, starting on 20 June 1893, though he mistook it for 15P/Finlay.
Orbital calculations in October 1893 showed that the comet had passed perihelion a day before the official discovery reports were made. It was last seen as a 6th-magnitude object on 3 August 1893, after which further observations became impossible due to its low position in the sky and the glare of a full Moon.
Quick Facts
- Discovery Ref
- Campbell_1893 · Holden_1893
- Discoverer
- Alfred Rordame / Ferdinand Quénisset
- Discovery Site
- Salt Lake City, USA / Juvisy-sur-Orge, France
- Discovery Date
- 8–9 July 1893
- Designations
- 1893bICQ1 / 1893 II
- Orbit Ref
- jpl
- Epoch
- 19 July 1893 (JD 2412663.5)
- Observation Arc
- 15 days
- Earliest Precovery Date
- 20 June 1893
- Obs
- 15
- Perihelion
- 0.6744 AU
- Eccentricity
- 1.001703
Facts from the source article.
Lore & Background
The comet was discovered independently by Alfred Rordame and Ferdinand Quénisset, who reported it on 8 and 9 July 1893 respectively. At that time it was a 3rd-magnitude object in the constellation Lynx. However, several other astronomers had already spotted the comet beforehand. Amateur astronomers J. Miller and C. Johnson claimed they observed it from Alta, Iowa about 2–3 hours before Rordame made his report to Lewis A. Swift. Across the Atlantic, Mario Roso de Luna reportedly saw the comet from Logrosan, Spain on 4 July, but did not recognize it as a new comet until August 1893, when orbital calculations confirmed it was the same object as Rordame–Quénisset. The earliest known prediscovery observations were made on 20 June 1893 by William E. Sperra, who observed the comet a dozen times from Randolph, Ohio but mistook it for 15P/Finlay.
Reader's Guide
The significance of C/1893 N1 lies in its disputed discovery and the multiple independent sightings that preceded its official recognition. The comet's hyperbolic orbit was determined by orbital calculations in October 1893, which showed it had already passed perihelion a day before the official discovery reports were made. Its visibility to the naked eye and its rapid fading—last observed as a 6th-magnitude object on 3 August 1893—highlight the challenges of observing comets that quickly move into unfavorable positions. The comet's legacy is tied to the confusion over priority of discovery, with several astronomers having seen it days or even weeks earlier without recognizing it as a new comet. The case illustrates how early comet discoveries often involved multiple claimants and the role of timely reporting in establishing credit.
Did You Know?
- The comet was a 3rd-magnitude object in the constellation Lynx at the time of its official discovery.
- William E. Sperra made the earliest known prediscovery observations on 20 June 1893, but mistook it for 15P/Finlay.
- Mario Roso de Luna saw the comet on 4 July 1893 but did not realize it was new until August 1893.
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