Talk:List of hyperbolic comets

"1P" entries
Surely all those historical apparitions of Halley's Comet should be excluded? Double sharp (talk) 11:03, 11 July 2017 (UTC)
 * Right, it's not hyperbolic. There are some entries for 109P as well. But this whole list strikes me as WP:INDISCRIMINATE and should be pruned to a few essentials, perhaps comets that were particularly bright, or only those which are notable enough to have a separate article. Wikipedia is not a database. — JFG talk 12:41, 11 July 2017 (UTC)
 * Well, as a first step I would like to suggest that we make this list actually correct by removing all those periodic comet entries, before deciding how to prune it – I agree that in its current form it is severely bloated and not very useful. ^_^ Double sharp (talk) 04:40, 13 July 2017 (UTC)

Actual hyperbolic comets
This list is very long, does it list all of comets with e >= 1.0 using heliocentric orbital elements from the JPL Small Body Database?

A more useful list would use barycentric orbital elements. Those can be collected using that database by clinking the link to a comet from the list its search engine produces. Then clicking on Ephemeris. On that page click the links to change Ephemeris Type to Elements, and Center to Solar System Barycenter (use @0 or @ssb). You can also use Time Span to change the intervals and the year the orbit is calculated, sometimes the orbital elements change if the comet gets close to a planet. About 50 years before the perihelion date the comets will be well away from the planets or you can just use 1600 for most of their orbits when they entered the Solar System. This will leave only a handful of comets with e > 1.0. Or if you wish to see which ones are currently on or will leave with hyperbolic orbits you can use the current date or some future date respectively. I'd also recommend leaving off comets that have poorly determined orbits, for example, those that are are flagged as two-body model = T (there are more than 1800 of these including most of the Kreutz sungrazers), if you select that option as one of the outputs in the search engine. Agmartin (talk) 19:58, 10 December 2018 (UTC)

These are the ones from the JPL Small Body Database that have barycentric semimajor axes less than 0 in A.D. 1600: C/1779 A1 (Bode) C/1786 P1 (Herschel) C/1849 G2 (Goujon) C/1853 R1 (Bruhns) C/1880 Y1 (Pechule) C/1881 N1 (Schaeberle) C/1892 Q1 (Brooks) C/1895 W1 (Perrine) C/1898 L2 (Perrine) C/1898 V1 (Chase) C/1899 E1 (Swift) C/1904 Y1 (Giacobini) C/1911 S3 (Beljawsky) C/1932 M1 (Newman) C/1940 S1 (Okabayasi-Honda) C/1942 C2 (Oterma) C/1946 C1 (Timmers) C/1946 P1 (Jones) C/1952 W1 (Mrkos) C/1955 O1 (Honda) C/1956 R1 (Arend-Roland) C/1959 O1 (Bester-Hoffmeister) C/1968 N1 (Honda) C/1971 E1 (Toba) C/1975 V2 (Bradfield) C/1975 X1 (Sato) C/1978 G2 (McNaught-Tritton) C/1978 H1 (Meier) C/1980 R1 (Russell) C/1983 O2 (IRAS) C/1986 P1-B (Wilson) C/1987 A1 (Levy) C/1990 K1 (Levy) C/1991 X2 (Mueller) C/1991 Y1 (Zanotta-Brewington) C/1993 Q1 (Mueller) C/1995 Y1 (Hyakutake) C/1996 E1 (NEAT) C/1997 BA6 (Spacewatch) C/1996 J1-A (Evans-Drinkwater) C/1996 J1-B (Evans-Drinkwater) C/1996 N1 (Brewington) C/1997 P2 (Spacewatch) C/1998 J1 (SOHO) C/2002 B3 (LINEAR) C/2002 E2 (Snyder-Murakami) C/2002 O4 (Hoenig) C/2004 H6 (SWAN) C/2007 W1 (Boattini) C/2008 A1 (McNaught) C/2008 J4 (McNaught) C/2008 J6 (Hill) C/2009 R1 (McNaught) C/2011 K1 (Schwartz-Holvorcem) C/2011 L2 (McNaught) C/2011 M1 (LINEAR) C/2011 N2 (McNaught) C/2011 Q2 (McNaught) C/2012 C2 (Bruenjes) C/2012 S1 (ISON) C/2012 T5 (Bressi) C/2013 A1 (Siding Spring) C/2015 E61-B (PANSTARRS) C/2016 U1 (NEOWISE) C/2017 T1 (Heinze) Agmartin (talk) 20:22, 10 December 2018 (UTC)

C/2017 Y1 (PANSTARRS) C/2017 Y2 (PANSTARRS) C/2018 V1 (Machholz-Fujikawa-Iwamoto) C/2019 E3 (ATLAS) C/2019 K7 (Smith) C/2019 L3 (ATLAS) C/2019 N1 (ATLAS) C/2019 Q4 (Borisov) (AKA 2I/Borisov) Agmartin (talk) 21:27, 3 October 2019 (UTC)

Being curious about how many of these were hyperbolic including the uncertainty of their orbits I calculated the semimajor axes using the vectors, available from the JPL SBDB, and their sigmas, available for most of those discovered after 1990. About 2/3 of those discovered after 1990 and with sigmas available are still hyperbolic: C/1990 K1 (Levy) C/1991 X2 (Mueller) C/1991 Y1 (Zanotta-Brewington) C/1996 E1 (NEAT) C/1996 J1-A (Evans-Drinkwater) C/1996 N1 (Brewington) C/1997 BA6 (Spacewatch) C/1998 J1 (SOHO) C/2002 B3 (LINEAR) C/2002 O4 (Hoenig) C/2004 H6 (SWAN) C/2007 W1 (Boattini) C/2008 A1 (McNaught) C/2008 J6 (Hill) C/2009 R1 (McNaught) C/2011 L2 (McNaught) C/2011 M1 (LINEAR) C/2011 Q2 (McNaught) C/2012 C2 (Bruenjes) C/2012 S1 (ISON) C/2012 T5 (Bressi) C/2015 E61-B (PANSTARRS) C/2017 T1 (Heinze) C/2018 V1 (Machholz-Fujikawa-Iwamoto) C/2019 Q4 (Borisov) (AKA 2I/Borisov) Agmartin (talk) 17:07, 4 October 2019 (UTC)