Great January Comet of 1910

C/1910 A1 (Great January Comet,
Daylight Comet)
C/1910 A1, the Daylight or Great January Comet, photograph from Lowell Observatory
Discovery
Discovered byMultiple observers
Discovery dateJanuary 12, 1910
Designations
1910 I
1910a
Orbital characteristics
EpochJanuary 9, 1910 (JD 2418680.5)
Observation arc82 days
Number of
observations		25 for JPL #3
Aphelion~1150 AU (inbound)
~900 AU (epoch 2000)[1]
Perihelion0.12896 AU (19.292 million km)
Semi-major axis~440 AU (epoch 2000)[1]
Eccentricity0.99978
Orbital period~9,200 yr (epoch 2000)[1]
Inclination138.78°
Last perihelionJanuary 17, 1910

The Great January Comet of 1910, formally designated C/1910 A1 and often referred to as the Daylight Comet,[2] was a comet which appeared in January 1910. It was already visible to the naked eye when it was first noticed, and many people independently "discovered" the comet. At its brightest, it outshone the planet Venus, and was possibly the brightest comet of the 20th century.[3]

  1. ^ a b c Cite error: The named reference barycenter was invoked but never defined (see the help page).
  2. ^ Moore, P. (2007), Space: The First 50 Years, New York: Sterling, p. 178, ISBN 978-1-4027-5208-7.
  3. ^ Cite error: The named reference bortle was invoked but never defined (see the help page).