C/1959 Q2 (Alcock)

For the other four comets discovered by George E. D. Alcock, see Comet Alcock.

Comet Alcock, formally designated as C/1959 Q2, is a relatively bright hyperbolic comet that only appeared for a week in September 1959. It was the second comet discovered by English astronomer George Alcock.

C/1959 Q2 (Alcock)

Comet Alcock imaged by Elizabeth Roemer from the US Naval Observatory on 1 September 1959.[1]
Discovery[2]
Discovered by	George E. D. Alcock
Discovery site	Peterborough, England
Discovery date	30 August 1959
Designations
Alternative designations	1959 VI, 1959f[3]
Orbital characteristics[4]
Epoch	4 September 1959 (JD 2436815.5)
Observation arc	5 days
Number of observations	14
Perihelion	0.166 AU
Eccentricity	1.00043
Inclination	108.04°
Longitude of ascending node	225.84°
Argument of periapsis	300.54°
Mean anomaly	–0.002°
Last perihelion	15 September 1959
Earth MOID	0.161 AU
Jupiter MOID	2.839 AU
Physical characteristics[5][6]
Comet nuclear magnitude (M2)	8.1–11.0
Apparent magnitude	4.7 (1959 apparition)

Observational history

Shortly after discovering C/1959 Q1 George Alcock found his second comet using a pair of binoculars on the night of 30 August 1959.^[2] He described the new comet as a diffuse, sixth-magnitude object with a central condensation and a small tail, located within the constellation Cancer.^[a]

Elizabeth Roemer took long-exposure photographs of the comet from the US Naval Observatory in 1 September 1959, reporting a sharply-condensed nucleus and a tail over a degree in length.^[1] By the following day, Alois Purgathofer,^[7] George van Biesbroeck, and D. P. Elias also observed the comet, where it was reported that the comet had slightly brightened to 5.7 in apparent magnitude.^[8] On 4 September it brightened further to magnitude 4.7.^[5]

The comet was last seen by Roemer on 6 September 1959 within the constellation Hydra,^[b] shortly before an expected solar conjunction the following day.^[9]