C/1911 O1 (Brooks)

For other comets discovered by William Robert Brooks, see Comet Brooks.

C/1911 O1 (Brooks)

Comet Brooks photographed by Paul L. Anderson shortly before its last perihelion, 19 October 1911
Discovery
Discovered by	William R. Brooks
Discovery site	Smith Observatory
Discovery date	21 July 1911
Designations
Alternative designations	1911c 1911 V
Orbital characteristics
Epoch	27 August 1911 (JD 2419275.5)
Observation arc	10 days
Number of observations	8
Aphelion	78.6906 AU
Perihelion	0.48982 AU
Semi-major axis	39.5902 AU
Eccentricity	0.98763
Orbital period	249.109 years
Inclination	33.8095°
Longitude of ascending node	293.704°
Argument of periapsis	153.557°
Last perihelion	28 October 1911
Next perihelion	~2160
TJupiter	0.854
Earth MOID	0.4167 AU
Jupiter MOID	0.4506 AU
Physical characteristics
Apparent magnitude	2.0 (1911 apparition)

C/1911 O1 (Brooks), also designated 1911 V or Comet Brooks, was a bright comet discovered in July 1911 by astronomer William Robert Brooks.

It is notable for becoming a bright naked-eye object of second magnitude, with a narrow straight tail of up to thirty degrees in length and a distinct blue colour; this colour seen in some comets is usually a result of the emission of carbon monoxide ions. It was also notable for uniquely being visible at the same time (mid October 1911) and in the same part of the sky as a second bright comet; this was C/1911 S3 (Beljawsky), which reached the first magnitude, had a fifteen degree tail and a bright golden-yellow appearance.