Comet of the Week: 3D/Biela 1846 II

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Special Topic: Stellar Intruders

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Special Topic: Centaurs

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Special Topic: Comet observations from space

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While, strictly speaking, it is not a “near-Earth” asteroid, an important asteroid has been discovered since I first put up this presentation. On January 4, 2020, the Zwicky Transient Facility survey, based at Palomar Observatory in California, discovered an 18th-magnitude object which was formally designated as 2020 AV2 when its discovery was announced on January …

JANUARY 5, 2005: The Kuiper Belt object now known as (136199) Eris is discovered by Mike Brown, Chad Trujillo, and David Rabinowitz on images taken in October 2003. Eris travels around the sun in a moderately-inclined and moderately eccentric orbit with a period of 558 years; it has one known moon (Dysnomia) and turns out …

Comet Machholz C/2004 Q2’s Perihelion: 2005 January 24.91, q = 1.205 AU Beginning with French astronomer Charles Messier and his contemporaries in the mid- to late 18th Century, the vast majority of comets were discovered visually by amateur astronomers who regularly swept the skies looking for these objects. While this means of comet discovery began …

Last week’s topic concerned the asteroids that occupy the so-called “main asteroid belt” between the orbits of Mars and Jupiter. The overwhelming majority of the first several hundred asteroids discovered, and, indeed, a large majority of the asteroids known today, reside in this region. However, as years went by and more and more asteroids kept …

JANUARY 1, 1801: On the first day of the 19th Century, Giuseppe Piazzi at the Palermo Observatory in Sicily discovers the first-known asteroid, now known as (1) Ceres. As a resident of the “main asteroid belt” between Mars and Jupiter, Ceres remains the largest-known asteroid (diameter 950 km), and is now formally designated a “dwarf …

Comet 81P/Wild 2’s Perihelion: 2003 September 25.93, q = 1.590 AU Comet 81P/Wild 2 was discovered on January 6, 1978, by Swiss astronomer Paul Wild, who photographically patrolled the skies for several decades from the University of Bern. Throughout that time he discovered numerous asteroids and supernovae, as well as eight comets; he has the …