C/1883 D1 (Brooks–Swift)

For other comets discovered by William R. Brooks and Lewis A. Swift, see Comet Brooks and Comet Swift.

Comet Brooks–Swift, also known as C/1883 D1 by its modern nomenclature, is a hyperbolic comet that was visible telescopically to Earth in the early months of 1883. It was discovered independently by two American astronomers, William Robert Brooks and Lewis A. Swift.^[3]

C/1883 D1 (Brooks–Swift)

Discovery
Discovered by	William R. Brooks Lewis A. Swift
Discovery site	New York, USA
Discovery date	24 February 1883
Designations
Alternative designations	1883a[1] 1883 I
Orbital characteristics[2]
Epoch	12 March 1883 (JD 2408881.5)
Observation arc	31 days
Number of observations	9
Perihelion	0.760 AU
Eccentricity	1.000077
Inclination	78.066°
Longitude of ascending node	279.77°
Argument of periapsis	110.89°
Last perihelion	19 February 1883
Earth MOID	0.110 AU
Jupiter MOID	1.824 AU
Physical characteristics
Apparent magnitude	6.0–7.0[a] (1883 apparition)

Discovery and observations

The comet was discovered on the morning of 24 February 1883 in the constellation Pegasus.^[b] Both Brooks and Swift spotted the comet about 25 minutes from one another, with initial orbital calculations suggesting it already passed perihelion on 19 February.^[4][5]

Nikolaus von Konkoly made spectroscopic observations of the comet on 3 March, two days after it made its closest approach to Earth at a distance of 1.156 AU (172.9 million km).^[6] Seth C. Chandler, Jr. watched the comet occult an 8th-magnitude star on the night of 5 March, which enabled him to measure the comet's apparent magnitude at the time.^[7] By late March, the comet started to fade away rapidly, until it was last observed within the constellation Orion on 24 April 1883.^[3]