Comet

Perihelion: 1973 December 28.43, q = 0.142 AU  This comet’s story starts about two years before its actual discovery when Brian Marsden (at the IAU’s Central Bureau for Astronomical Telegrams) performed some orbital calculations of the long-lost periodic Comet 3D/Biela (a previous “Comet of the Week”). The comet had not been seen since the mid-19th Century …

Perihelion: 2011 December 16.08, q = 0.006 AU  In the “Special Topics” presentation on Kreutz sungrazers eight weeks ago I mentioned that in 2007 Zdenek Sekanina and Paul Chodas published a paper wherein they predicted that a new “cluster” of sungrazers should be arriving within the next few decades, with “its earliest member possibly just several …

Perihelion: 1680 December 18.49, q = 0.006 AU  This particular comet was undoubtedly one of the brightest comets of the 17th Century, but it is also one of the most important comets in history from a scientific perspective, and perhaps even from the perspective of overall human history. While there were certainly plenty of superstitions attached …

Perihelion: 2013 December 22.73, q = 0.812 AU  I’ve mentioned in some of the previous “Ice and Stone 2020” presentations that, until the appearance of Comet NEOWISE C/2020 F3 earlier this year, the northern hemisphere had not had what could be considered a “Great Comet” in well over two decades. We did have a moderately bright …

Perihelion: 1992 December 12.32, q = 0.958 AU  One of the most prolific comet discoverers of the late 19th Century was the American amateur astronomer Lewis Swift, who did most of his observing from rural New York before relocating to southern California in the early 1890s. Swift discovered his first comet, a 7th-magnitude object, on July …

Perihelion: 2013 November 28.78, q = 0.012 AU  I mentioned in the “Special Topics” presentation on “Great Comets” that such objects come by about once a decade, on average. Comet NEOWISE C/2020 F3, which appeared back in July, could perhaps be considered a borderline “Great” comet, but prior to that, the last “Great Comet” for those of …