Great Comet of 1472
Closest great comet approach in modern times, observed for 59 days.
The Great Comet of 1472, known today as C/1471 Y1, appeared in the sky for 59 days, from Christmas Day 1471 until 1 March 1472 on the Julian Calendar. On 22 January 1472, it came within 0.07 AU of Earth—roughly 10 million kilometers—making it the closest approach of any great comet in modern times.
First spotted in the constellation Virgo on Christmas 1471, the comet grew brighter in early January 1472. Korean observers noted a tail 4 to 5 degrees long as it moved north through Bootes, Coma Berenices, and Ursa Major. By 22 January, it sat about 15 degrees from the north celestial pole, moving at roughly one degree per hour. It then shifted south toward perihelion, becoming more visible in the evening sky. The last sighting came around 11 March, when the comet was in Cetus.
Italian physician Angelo Cato de Supino described the comet as bright and majestic as the full moon, with a tail stretching over 30 degrees. Astronomer Regiomontanus reported the tail measured 50 degrees on 20 January. Chinese records call it a “broom star” and note it was visible even at midday. English chronicler John Warkworth also left a detailed account of its appearance and disappearance over England.
Regiomontanus and Bernhard Walther observed the comet from Nuremberg. Regiomontanus attempted to measure its distance using parallax, estimating it at least 8,200 miles away. Based on that, he calculated the central condensation as 26 miles and the entire coma as 81 miles in diameter. Though these figures are far too small, his effort to determine the comet’s physical size was pioneering. The comet’s 0.07 AU perigee remains the closest for any great comet in modern times, with only the Great Comet of 1556 and Comet Hyakutake coming similarly near since.
Quick Facts
- Discovery Date
- 25 December 1471
- Orbit Ref
- jpl
- Epoch
- 1 March 1472 (JD 2258765.939)
- Observation Arc
- 12 days
- Obs
- 3
- Perihelion
- 0.4859 AU
- Eccentricity
- ~1.000
- Inclination
- 170.866°
- Asc Node
- 292.873°
- Arg Peri
- 245.728°
- Last P
- 1 March 1472
Facts from the source article.
Lore & Background
The first reports of the comet date from Christmas Day 1471, when it was located in Virgo. It became better visible in the second week of January 1472, when Korean sources mention a tail 4–5° long. The comet moved northwards through Bootes, Coma Berenices and Ursa Major, and was about 15 degrees from the north celestial pole on 22 January, the date of perigee, moving about one degree per hour. It then moved southwards towards perihelion and became better visible in the evening sky, last observed around 11 March in Cetus.
An Italian physician named Angelo Cato de Supino described the comet as bright and majestic as the full moon, with a tail extending over more than 30 degrees. Regiomontanus mentioned that on 20 January the tail measured 50 degrees in length. Chinese astronomy noted the comet was visible even at midday. The 15th-century English chronicler John Warkworth left a detailed account of its appearance and disappearance from the night sky of England.
Reader's Guide
The Great Comet of 1472 is significant because it was observed by 15th-century astronomers during a time of rapid progress in planetary theory, shortly before the Copernican Revolution. Regiomontanus and Bernhard Walther observed it from Nuremberg, and Regiomontanus attempted to estimate its distance from Earth using parallax. In agreement with prevailing Aristotelian theory that comets were atmospheric phenomena, he estimated its distance at least 8,200 miles (13,120 km) and derived a central condensation diameter of 26 miles and entire coma diameter of 81 miles (41.6 and 129.6 km respectively). These values fail by orders of magnitude, but the attempt at determining physical dimensions is commended. The comet is now known to have passed 0.07 AU from Earth, the closest approach of a great comet in modern times; only the Great Comet of 1556 and Comet Hyakutake have approached comparably since.
Did You Know?
- The comet was visible for 59 days, from Christmas Day 1471 to 1 March 1472 (Julian Calendar).
- It passed 0.07 AU from Earth on 22 January 1472, closer than any other great comet in modern times.
- Regiomontanus estimated its distance using parallax, deriving a coma diameter of 81 miles.
- Chinese astronomy recorded that the comet was visible even at midday.
More in Named Comets, Part 3 1-24
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