C/1905 X1 (Giacobini)

For other comets discovered by Michel Giacobini, see Comet Giacobini.

Giacobini's Comet, also known as C/1905 X1, is a bright parabolic comet that became visible to the naked eye in January 1906. It is one of 12 comets discovered by French astronomer, Michel Giacobini.

C/1905 X1 (Giacobini)

Giacobini's Comet photographed by Edward E. Barnard on 29 December 1905[1]
Discovery
Discovered by	Michel Giacobini
Discovery site	Nice, France
Discovery date	7 December 1905
Designations
Alternative designations	1905c[2] 1906 I
Orbital characteristics[3]
Epoch	13 January 1906 (JD 2417223.5)
Observation arc	81 days
Number of observations	41
Perihelion	0.216 AU
Eccentricity	~1.000
Inclination	43.65°
Longitude of ascending node	93.37°
Argument of periapsis	199.22°
Last perihelion	22 December 1906
Earth MOID	0.413 AU
Jupiter MOID	0.253 AU
Physical characteristics[4]
Comet nuclear magnitude (M2)	8.3
Apparent magnitude	0.7 (1906 apparition)

Observational history

While observing at the Nice Observatory in France, Michel Giacobini discovered the comet as an 8th-magnitude object within the constellation Boötes.^[a] Throughout December 1905, the comet continued to brighten as it slowly approached both the Earth and the Sun, allowing follow-up observations to be conducted.