List of Halley-type comets
Unnumbered HTCs
This list contains only Halley-type comets which are not numbered yet because they have been observed only once.

List of Halley-type comets

Section Title: Unnumbered HTCs
Table Section Text: This list contains only Halley-type comets which are not numbered yet because they have been observed only once.

Comet designation	Comet name	Eccentricity	Semimajor axis (AU)	Period (years)	Inclination (°)	Perihelion distance (AU)	Absolute magnitude	Last perihelion	Next perihelion	Ref

C/1625 A1	0.9183	9.05	27.21	28.98	0.7391	1625/01/31	?	–

C/1917 F1	Mellish	0.993121	27.6473325	145	32.6828	0.190186	1917/04/11	2062	JPL

C/1921 H1	Dubiago	0.86	8	22	22.11	1.1008	1921/05/04	2031	JPL

C/1937 D1	Wilk	0.981098	32.7445244	187	26.0205	0.618937	1937/02/21	2124	JPL

C/1942 EA	Väisälä	0.933639	19.3951116	85.4	37.9961	1.287079	1942/02/15	2027/07/10	JPL

C/1984 A1	Bradfield 1	0.9524	28.5	152.3	51.8005	1.35751	9.6	1983/12/27	2136/04/01	JPL

C/1989 A3	Bradfield	0.977708	18.853	81.9	83.0672	0.420271	1988/12/05	2070/11/01	JPL

C/1991 L3	Levy	0.928811	13.8018	51.28	19.19031	0.982545	8.8	1991/07/08	2042/10/19	JPL

P/1997 B1	Kobayashi (*JFC)	0.76076	8.588	25.17	12.3495	2.05455	12.3	1997/03/02	2022/06/06	JPL

C/1998 G1	LINEAR	0.8237	12.099	42.08	109.714	2.1333	10.8	1998/11/16	2040/12/15	JPL

C/1998 Y1	LINEAR	0.9239	22.956	110	28.1082	1.74699	14	1998/11/21	2108/11/15	JPL

C/1999 E1	Li	0.76011	16.341	66.06	46.88108	3.92002	8.3	1998/01/31	2065/02/21	JPL

C/1999 G1	LINEAR	0.856	28.1	149	76.55	4.048	8	1998/08/01	2150	JPL

C/1999 K4	LINEAR	0.92	20	70	120.8	1.442	18.5	1999/05/16	2069/06/08	JPL

C/1999 S3	LINEAR	0.89995	18.94	82.43	70.5607	1.894939	4.9	1999/11/09	2081/04/04	JPL

C/1999 XS87	LINEAR (*JFC)	0.84057	17.386	72.5	14.8464	2.7718	10.9	1999/08/06	2072/02/04	JPL

C/2000 D2	LINEAR	0.867	17.2	72	156.992	2.2975	13.7	2000/03/08	2072	JPL

C/2000 G2	LINEAR	0.805	14	52	170.4785	2.716	12.8	2000/02/05	2052	JPL

C/2000 S3	LONEOS (*JFC)	0.7723	11.69	39.97	25.164	2.6622	6.4	2000/07/16	2040/07/10	JPL

C/2001 M10	NEAT (*JFC)	0.80107	26.657	137.63	28.08349	5.30275	9.4	2001/06/21	2139/02/01	JPL

C/2001 OG108	LONEOS	0.9252595	13.3	48.5	80.24505	0.9940479	13.2	2002/03/15	2050/09/13	JPL

P/2001 Q6	NEAT	0.82386	7.9946	22.61	56.8553	1.408179	13.3	2001/11/09	2024/06/20	JPL

C/2001 W2	BATTeRS	0.94136	17.925	75.89	115.9131	1.051065	12.1	2001/12/23	2077/11/15	JPL

C/2002 A1	LINEAR (*JFC)	0.72281	16.992	70.04	14.03393	4.70996	8.6	2001/11/26	2071/12/11	JPL

C/2002 A2	LINEAR (*JFC)	0.72482	17.103	70.74	14.0386	4.70659	7.5	2001/12/05	2072/09/01	JPL

C/2002 B1	LINEAR	0.77102	9.9183	31.24	51.0214	2.27113	6.3	2002/04/20	2032/06/17	JPL

C/2002 CE10	LINEAR	0.791486	9.81595	30.75	145.4587	2.0467593	10.8	2003/06/22	2034/03/23	JPL

C/2002 K4	NEAT	0.84232	17.532	73.41	94.0632	2.76453	11.4	2002/07/12	2075/12/01	JPL

P/2002 T6	NEAT–LINEAR (*JFC)	0.557348	7.6519	21.17	11.00927	3.387103	5.9	2003/06/27	2024/08/28	JPL

C/2003 E1	NEAT (*JFC)	0.76359	13.7263	50.86	33.53785	3.245004	10.6	2004/02/13	2054/12/24	JPL

C/2003 F1	LINEAR	0.80605	20.664	93.93	70.2216	4.007806	8.3	2003/06/28	2097/06/02	JPL

P/2003 QX29	NEAT (*JFC)	0.4718	8.0255	22.74	11.3965	4.239	6.1	2002/10/26	2025/07/21	JPL

C/2003 R1	LINEAR	0.89331	19.7	87.44	149.19563	2.10188	12.7	2003/06/29	2090/12/15	JPL

C/2003 U1	LINEAR	0.9216	22.9	109.6	164.4745	1.79572	15.2	2003/11/03	2113	JPL

C/2003 W1	LINEAR	0.93429	25.15	126.1	78.0756	1.65241	13.5	2003/11/09	2130	JPL

P/2004 A1	LONEOS (*JFC)	0.30841	7.89853	22.2	10.57568	5.462544	10	2004/08/26	2026/11/07	JPL

C/2004 C1	Larsen (*JFC)	0.6231	11.566	39.33	28.918	4.3594	10	2003/03/19	2042/09/01	JPL

P/2004 DO29	Spacewatch–LINEAR (*JFC)	0.45151	7.4655	20.4	14.5358	4.09475	10.3	2004/10/11	2025/03/06	JPL

P/2004 V5-A	LINEAR–Hill (*JFC)	0.445217	7.95059	22.42	19.358136	4.410853	8.8	2005/02/28	2027/07/31	JPL

P/2004 V5-B	LINEAR–Hill (*JFC)	0.445233	7.95092	22.42	19.35822	4.41091	9.2	2005/03/01	2027/08/02	JPL

C/2005 N5	Catalina	0.94327	28.687	153.65	21.37879	1.6274	12.9	2005/08/22	2159/01/01	JPL

C/2005 O2	Christensen	0.85939	23.707	115.43	148.89204	3.33358	5.2	2005/09/08	2121/02/15	JPL

P/2005 S2	Skiff (*CTC)	0.1967	7.965	22.48	3.141	6.398	7.9	2006/06/30	2028/12/22	JPL

P/2005 T3	Read (*CTC)	0.174	7.509	20.58	6.26	6.202	9.2	2006/01/13	2026/08/15	JPL

P/2005 T4	SWAN	0.93	9.3	28.4	160.0362	0.649399	15.4	2005/10/10	2034	JPL

C/2005 W2	Christensen (*JFC)	0.82446	18.979	82.68	11.26403	3.33162	10.8	2006/03/27	2096/12/01	JPL

C/2006 F2	Christensen (*JFC)	0.65138	12.324	43.27	20.511	4.2965	10.6	2006/05/30	2049/09/06	JPL

P/2006 HR30	Siding Spring	0.8431184	7.81754	21.86	31.884499	1.2264277	11.7	2007/01/02	2028/11/12	JPL

C/2006 U7	Gibbs (*JFC)	0.6309	11.99	41.51	57.762	4.425	11.6	2007/03/28	2048/10/01	JPL

C/2007 S2	Lemmon (*JFC)	0.557056	12.5477	44.45	16.86305	5.557931	9	2008/09/14	2053/02/25	JPL

C/2008 E1	Catalina (*JFC)	0.54815	10.687	34.94	35.03769	4.82891	9.1	2008/08/11	2043/07/31	JPL

P/2008 O3	Boattini (*JFC)	0.6949	8.186	23.42	32.2699	2.4973	5.1	2008/06/03	2031/11/03	JPL

C/2008 R3	LINEAR	0.89641	18.428	79.11	43.23793	1.909035	13.5	2008/11/22	2088/01/01	JPL

P/2008 Y3	McNaught (*JFC)	0.44766	8.0281	22.75	38.81318	4.434241	8.7	2009/01/11	2031/10/12	JPL

P/2009 O3	Hill (*JFC)	0.68688	7.8244	21.89	16.2176	2.44999	12	2009/05/18	2031/04/08	JPL

P/2009 Q5	McNaught (*JFC)	0.609061	7.4654	20.4	40.9048	2.91851	10.5	2009/09/08	2030/02/02	JPL

P/2009 T2	La Sagra (*JFC)	0.768991	7.596	20.94	28.10639	1.75475	14.2	2010/01/12	2030/12/21	JPL

P/2010 E2	Jarnac (*JFC)	0.72237	8.6402	25.4	15.437	2.39874	14.4	2010/04/07	2035/08/31	JPL

C/2010 E5	Scotti (*JFC)	0.84274	24.73	122.96	18.9102	3.8884	6.1	2009/11/21	2132/11/01	JPL

P/2010 J3	McMillan (*JFC)	0.72682	8.9871	26.94	13.25507	2.45511	11.6	2010/08/23	2037/08/01	JPL

P/2010 JC81	WISE	0.77735	8.13307	23.19	38.69025	1.8108311	10.3	2011/04/26	2034/07/04	JPL

C/2010 L5	WISE	0.904	8.2	23.6	147.052	0.7909	17.4	2010/04/23	2033	JPL

C/2011 J3	LINEAR	0.9258	19.56	86.5	114.7124	1.451	13.1	2011/01/24	2097	JPL

P/2011 JB15	Spacewatch–Boattini	0.31874	7.3668	20	19.14127	5.01871	5.5	2012/01/21	2032/01/21	JPL

C/2011 L1	McNaught	0.79678	11.034	36.66	65.512	2.24237	10.6	2010/12/18	2047/08/15	JPL

P/2011 P1	McNaught (*JFC)	0.3598	7.741	21.54	6.1741	4.9556	8.2	2010/07/22	2032/02/04	JPL

C/2011 P2	PANSTARRS (*CTC)	0.36982	9.7562	30.47	8.98964	6.1481	6.7	2010/09/13	2041/03/04	JPL

P/2011 S1	Gibbs (*CTC)	0.20305	8.6545	25.46	2.6792	6.8972	5.5	2014/08/20	2040/02/04	JPL

C/2011 S2	Kowalski	0.9316	16.304	65.83	17.57253	1.115118	14.8	2011/10/26	2077/08/25	JPL

C/2011 Y3	Boattini (*JFC)	0.705	11.85	40.82	26.517	3.4978	11.7	2011/08/22	2052/06/17	JPL

C/2012 BJ98	Lemmon (*JFC)	0.87365	17.068	70.52	2.6369	2.156577	8.1	2012/09/20	2083/03/29	JPL

P/2012 C3	PANSTARRS (*JFC)	0.6264	9.7	30.2	9.19	3.625	13.5	2011/10/05	2042	JPL

A/2012 CG	Lemmon	0.499315	28.9980	156.16	14.58112	14.51886	9.0	2001/06/29	2157/08/26	JPL

C/2012 H2	McNaught	0.8936	16.14	64.9	92.8355	1.71678	15.7	2012/05/03	2077	JPL

P/2012 NJ	La Sagra	0.848062	8.5027	24.79	84.37546	1.2918901	13.1	2012/06/13	2037/03/28	JPL

C/2012 Q1	Kowalski (*JFC)	0.63722	26.138	133.63	45.181	9.48222	4.7	2012/02/09	2145/10/01	JPL

C/2012 T6	Kowalski	0.87634	14.354	54.38	33.2755	1.77509	15.7	2012/08/26	2067/01/15	JPL

C/2012 X2	PANSTARRS (*JFC)	0.77052	20.69	94.12	34.12389	4.74816	9.6	2013/03/31	2107/05/14	JPL

C/2012 Y3	McNaught	0.93993	29.38	159.3	73.2318	1.76482	10.4	2012/08/25	2172	JPL

C/2013 C2	Tenagra (*CTC)	0.4293	16.001	64.01	21.34426	9.1321	4.4	2015/08/28	2080/09/01	JPL

C/2013 D1	Holvorcem (*JFC)	0.78088	11.227	37.62	10.09356	2.46013	13.5	2013/04/13	2050/11/25	JPL

P/2013 N3	PANSTARRS (*JFC)	0.5924	7.431	20.26	2.17041	3.0289	6.6	2014/02/11	2034/05/17	JPL

P/2013 P1	PANSTARRS (*JFC)	0.6053	8.588	25.17	18.702	3.3902	11.6	2013/02/26	2038/04/29	JPL

C/2013 P4	PANSTARRS (*CTC)	0.59636	14.783	56.84	4.26425	5.96703	5.1	2014/08/12	2071/06/15	JPL

C/2013 U1	Catalina (*JFC)	0.7971	11.92	41.17	23.9415	2.4188	13.9	2013/11/18	2055/01/01	JPL

C/2013 V3	Nevsky	0.89097	12.718	45.36	32.1345	1.386693	15.2	2013/10/29	2059/03/09	JPL

C/2013 W2	PANSTARRS (*JFC)	0.561	10.13	32.23	4.5436	4.448	5.8	2015/01/08	2047/03/15	JPL

C/2014 F3	Sheppard–Trujillo (*JFC)	0.65	16.3	66	6.48	5.7	6.1	2021/04/17	2087	JPL

C/2014 HU195	Valdes–TOTAS (*JFC)	0.76580	21.867	102.25	5.82227	5.12113	14.6	2015/05/18	2117/08/14	JPL

C/2014 J1	Catalina	0.802	8.64	25.4	159.696	1.7085	16.8	2014/06/20	2039	JPL

P/2014 L3	Hill (*JFC)	0.77309	8.1706	23.36	6.264	1.85396	13.7	2014/06/28	2037/11/06	JPL

P/2014 O3	PANSTARRS (*JFC)	0.3847	7.544	20.72	7.81	4.642	10.4	2014/04/16	2035/01/04	JPL

C/2014 Q3	Borisov	0.94207	28.436	151.64	89.94888	1.647408	8.8	2014/11/19	2166/07/10	JPL

C/2014 TG64	Catalina (*JFC)	0.7824	14.89	22.283	3.2391	3.24	6.4	2014/05/26	2072	JPL

C/2014 W7	Christensen	0.869	11.3	38	98.314	1.4881	16.3	2014/12/31	2052	JPL

C/2014 W9	PANSTARRS	0.8577	11.16	37.28	10.6302	1.5874	15.5	2015/02/15	2052/04/01	JPL

C/2014 W11	PANSTARRS (*JFC)	0.650255	9.7980	30.67	12.70679	3.426805	8.8	2015/06/17	2036/04/16	JPL

C/2015 A1	PANSTARRS	0.900816	20.119	90.24	80.36576	1.995505	6.9	2015/03/13	2105/06/09	JPL

P/2015 A3	PANSTARRS	0.85	7.6	21	172.51	1.154	20.2	2015/02/22	2036	JPL

P/2015 B1	PANSTARRS (*JFC)	0.38250	9.6772	30.10	18.027	5.97567	8.7	2015/09/19	2045/10/26	JPL

P/2015 B4	Lemmon–PANSTARRS (*JFC)	0.56894	8.7121	25.72	1.74262	3.75540	11.7	2015/02/17	2030/12/04	JPL

C/2015 D2	PANSTARRS (*JFC)	0.56826	12.985	46.79	31.8339	5.6060	6.3	2013/09/27	2060/07/13	JPL

C/2015 D5	Kowalski (*JFC)	0.4996	9.145	27.66	20.3990	4.576	6.0	2014/04/16	2041/12/12	JPL

C/2015 F5	SWAN–XingMing	0.97764	15.47	60.9	149.2590	0.345995	17.6	2015/03/28	2075/02/01	JPL

C/2015 GX	PANSTARRS	0.878198	16.1883	65.13	90.25454	1.971753	14.4	2015/08/26	2080/10/09	JPL

C/2015 H1	Bressi	0.94078	32.53	185.5	140.65558	1.92636	6.6	2015/03/28	2200/10/07	JPL

P/2015 Q2	Pimentel	0.7544	7.407	20.16	146.2022	1.81912	15.3	2015/09/10	2035/11/06	JPL

C/2015 T5	Sheppard–Tholen (*CTC)	0.6661	27.97	147.9	11.0483	9.3383	7.7	2016/01/24	2164	JPL

C/2015 V4	PANSTARRS	0.70567	18.550	79.89	60.7513	5.45972	8.7	2016/08/27	2096/07/19	JPL

C/2015 X2	PANSTARRS	0.8791	15.75	62.5	72.458	1.90456	16.1	2015/12/20	2078/06/25	JPL

C/2015 X4	Elenin (*JFC)	0.812807	18.1345	77.23	29.50491	3.39466	10.1	2015/11/03	2093/02/14	JPL

C/2015 YG1	NEOWISE	0.87924	17.169	71.14	57.3360	2.07341	12.3	2015/09/28	2086/11/17	JPL

P/2016 A3	PANSTARRS (*JFC)	0.3778	7.6979	21.36	8.5929	4.7895	5.4	2017/04/13	2038/08/22	JPL

C/2016 Q4	Kowalski (*CTC)	0.5781	16.79	68.8	7.2567	7.084	7.0	2018/01/28	2086	JPL

C/2016 S1	PANSTARRS	0.70887	8.285	23.85	94.6898	2.41193	7.5	2017/03/16	2041/01/20	JPL

A/2016 TP93	PANSTARRS	0.56	7.5	20.6	138.31	3.291	15.7	2016/10/05	2038	JPL

A/2016 VY17	Lemmon	0.852	11.3	38	148.42	1.666	15.8	2017/07/02	2055	JPL

P/2016 WM48	Lemmon	0.7867	8.1954	23.46	117.5476	1.7480	16.8	2017/02/26	2040	JPL

C/2017 C1	NEOWISE	0.9263697	20.7832	92.08	65.73154	1.50172	2017/01/19	2109	JPL

P/2017 D4	PANSTARRS (*JFC)	0.62898	7.424	20.23	10.3396	2.7545	12.7	2016/09/06	2036/11/29	JPL

C/2017 E2	Tsuchinshan	0.89085	21.5567	100.09	79.1686	2.35295	11.3	2016/05/12	2116/06/14	JPL

P/2017 G1	PANSTARRS (*JFC)	0.66134	7.7387	21.53	3.534	2.621	13.1	2016/05/14	2037/11/23	JPL

P/2017 G2	PANSTARRS	0.65031	8.1394	23.22	47.90625	2.846	12.9	2017/06/13	2040/09/02	JPL

C/2017 K4	ATLAS (*JFC)	0.90571	28.0883	148.87	16.67822	2.64824	7.2	2018/01/08	2167	JPL

P/2017 P1	PANSTARRS (*JFC)	0.3088	7.86566	22.06	7.7013	5.43665	10.1	2018/06/18	2040/07/10	JPL

C/2017 S2	PANSTARRS (*JFC)	0.82406	20.5400	93.09	12.67723	3.613	13.2	2017/08/28	2110	JPL

C/2017 U5	PANSTARRS (*JFC)	0.74457	16.939	69.72	18.9566	4.32676	11.8	2017/12/19	2087/09/07	JPL

C/2017 W2	Leonard	0.7115	13.7176	50.81	98.1831	3.958	10.9	2017/11/02	2068	JPL

P/2017 W3	Gibbs (*JFC)	0.5039	7.734	21.51	18.317	3.8373	10.5	2018/02/25	2039/08/30	JPL

C/2017 X1	PANSTARRS (*JFC)	0.8511	31.3092	175.19	31.3106	4.6624	9.6	2018/06/14	2193	JPL

P/2017 Y3	Leonard	0.8703	9.838	30.86	27.5859	1.2753	13.6	2018/02/11	2049	JPL

C/2018 A1	PANSTARRS	0.9061	25.8169	131.18	53.6213	2.4233	13.1	2017/10/20	2148	JPL

C/2018 A6	Gibbs	0.8273	17.434	72.80	77.454	3.011	8.9	2019/07/08	2092	JPL

C/2018 K1	Weiland	0.9371	29.890	163.42	164.193	1.879	11.9	2018/04/06	2182	JPL

C/2018 M1	CSS	0.9409	22.087	103.81	37.265	1.304	15.9	2018/07/10	2122	JPL

C/2018 O1	ATLAS	0.944	27.864	147.09	154.041	1.558	12.6	2018/08/31	2165	JPL

C/2018 R5	Lemmon	0.8418	22.8947	109.55	103.76	3.6213	6	2019/01/09	2128	JPL

C/2018 V2	ATLAS	0.9034	25.616	129.65	159.111	2.475	14.5	2018/11/26	2148	JPL

C/2018 W1	CSS	0.938	21.779	101.64	83.273	1.36	15.648	2019/05/11	2120	JPL

C/2018 X3	PANSTARRS	0.783	12.41686	43.75	43.368	2.69887	15.5	2018/12/30	2062	JPL

P/2018 Y2	Africano (*JFC)	0.4878	7.543	20.72	11.48886	3.8635	11	2018/12/13	2039	JPL

Sentence(s)

The comets named after Scott S. Sheppard are Sheppard-Trujillo (C/2014 F3) and Sheppard-Tholen (C/2015 T5).

final_sentence: The comets named after Scott S. Sheppard are Sheppard-Trujillo (C/2014 F3) and Sheppard-Tholen (C/2015 T5).