Norse group

The Norse group is a large group of retrograde irregular satellites of Saturn. Their semi-major axes range between 12 and 27 Gm, their inclinations between 136° and 178° and their eccentricities between 0.06 and 0.63. Unlike the Inuit and Gallic groups, the orbital parameters are widely dispersed and the group is likely to be composed from a number of subgroups with more homogeneous orbital and physical parameters. The International Astronomical Union (IAU) reserves names taken from Norse mythology (mostly giants) for the satellites, with the exception of Phoebe (Greek mythology), the largest, which was discovered long before the others.

Diagram illustrating the orbits of the irregular satellites of Saturn, with major groups and moons labeled. The inclination and semi-major axis are represented on the Y and X-axis, respectively. The satellites with inclinations below 90° are prograde, those above 90° are retrograde. The X-axis is labeled in terms of Saturn's Hill radius.

The discovery of 17 new satellites in this group was announced in October 2019. A team led by Scott S. Sheppard using the Subaru Telescope at Mauna Kea discovered 20 new moons, each about 5 kilometres (3.1 miles) in diameter. 17 of these are thought to fit into the Norse group. One of these is the most distantly orbiting satellite of Saturn. A public naming contest for the satellites was announced, restricted to names from Norse mythology.^[1] Ten of the satellites received official names in August 2022.^[2]

The members of the group are (in order of increasing distance from Saturn according to JPL mean orbital elements):^[3]

Name	Diameter (km)	Period (days)	Subgroup[4]
Phoebe	213	–550.30	Phoebe
S/2006 S 20	5	–567.27	Phoebe[5][6][a]
S/2004 S 56	5	–596.13	Mundilfari
S/2023 S 8	3	–640.29	Mundilfari
S/2006 S 9	3	–647.89	Phoebe[7][a]
S/2023 S 11	3	–688.71	Mundilfari
S/2006 S 21	3	–689.14	Mundilfari
S/2023 S 9	3	–693.36	Mundilfari
S/2006 S 22	3	–695.44	Mundilfari
S/2023 S 10	3	–715.36	Mundilfari
Skathi	8	–728.10	Low-inclined
S/2023 S 12	3	–741.97	Mundilfari
S/2007 S 5	4	–746.88	Mundilfari
S/2007 S 7	4	–754.29	Mundilfari
S/2007 S 2	5	–754.90	Phoebe
S/2004 S 37	4	–754.48	Mundilfari
S/2004 S 47	4	–762.49	Mundilfari
S/2004 S 40	4	–764.60	Mundilfari
S/2020 S 14	3	–761.16	Mundilfari
S/2019 S 27	3	–768.34	Mundilfari
S/2023 S 13	3	–780.05	Mundilfari
S/2019 S 2	3	–799.82	Phoebe
S/2019 S 3	4	–837.74	Mundilfari
S/2020 S 17	4	–833.41	Low-inclined
S/2020 S 16	3	–836.55	Mundilfari
S/2023 S 14	3	–840.04	Mundilfari
S/2023 S 16	3	–845.58	Mundilfari
S/2020 S 7	3	–861.70	Mundilfari
S/2023 S 15	3	–868.77	Mundilfari
S/2023 S 50	3	–872.57	Mundilfari
Skoll	6	–878.44	Mundilfari
S/2019 S 28	4	–877.99	Kari
S/2020 S 18	3	–885.15	Mundilfari
S/2019 S 30	3	–888.77	Mundilfari
S/2020 S 2	3	–897.60	Mundilfari
S/2023 S 4	3	–897.55	Mundilfari
S/2019 S 4	3	–904.26	Mundilfari
S/2023 S 20	3	–901.92	Low-inclined
S/2004 S 41	4	–914.61	Mundilfari
S/2004 S 57	4	–910.59	Mundilfari
S/2020 S 20	3	–911.64	Mundilfari
S/2006 S 24	3	–912.40	Mundilfari
S/2004 S 42	4	–925.91	Mundilfari
Hyrrokkin	8	–931.89	Low-inclined
Greip	5	–936.98	Phoebe
S/2006 S 25	3	–930.69	Kari
S/2019 S 35	3	–934.06	Mundilfari
S/2004 S 13	4	–942.57	Mundilfari
S/2007 S 6	3	–949.50	Mundilfari
Mundilfari	7	–952.95	Mundilfari
S/2023 S 21	3	–948.97	Mundilfari
S/2020 S 21	3	–950.01	Mundilfari
S/2006 S 26	3	–951.35	Phoebe
S/2006 S 1	5	–964.14	Kari
S/2019 S 33	4	–972.41	Mundilfari
S/2004 S 43	4	–980.08	Mundilfari
S/2006 S 10	3	–983.14	Mundilfari
S/2019 S 5	3	–991.44	Mundilfari
S/2004 S 59	3	–985.45	Mundilfari
S/2023 S 23	3	–994.23	Mundilfari
S/2020 S 22	3	–995.61	Mundilfari
Gridr	4	–1004.75	Mundilfari
Bergelmir	5	–1005.58	Mundilfari
Jarnsaxa	6	–1006.92	Mundilfari
Narvi	7	–1003.84	Low-inclined
S/2023 S 24	3	–1004.22	Mundilfari
Suttungr	7	–1016.71	Phoebe
S/2004 S 60	3	–1010.44	Phoebe
S/2006 S 27	4	–1010.55	Mundilfari
S/2004 S 44	5	–1026.16	Mundilfari
S/2020 S 23	3	–1023.66	Mundilfari
S/2023 S 27	3	–1025.54	Low-inclined
S/2007 S 3	5	–1026.35	Phoebe
S/2004 S 45	4	–1038.70	Kari
Hati	5	–1040.29	Mundilfari
S/2004 S 17	4	–1040.86	Mundilfari
S/2006 S 11	3	–1042.28	Phoebe
S/2023 S 25	3	–1035.16	Mundilfari
S/2004 S 12	4	–1048.57	Mundilfari
Eggther	6	–1052.33	Mundilfari
S/2006 S 13	4	–1060.63	Mundilfari
S/2019 S 37	3	–1054.40	Low-inclined
S/2023 S 28	3	–1058.58	Mundilfari
S/2019 S 36	3	–1062.04	Mundilfari
S/2007 S 9	4	–1078.07	Mundilfari
S/2019 S 7	4	–1080.29	Phoebe
S/2019 S 8	4	–1088.68	Phoebe
Farbauti	5	–1087.29	Mundilfari
S/2023 S 26	3	–1080.53	Mundilfari
Thrymr	9	–1091.84	Phoebe
Bestla	8	–1087.46	Low-inclined
S/2019 S 9	4	–1093.11	Mundilfari
S/2023 S 48	3	–1090.97	Mundilfari
S/2004 S 46	3	–1107.58	Phoebe
Angrboda	4	–1114.05	Phoebe
S/2020 S 24	3	–1106.53	Mundilfari
S/2019 S 11	4	–1115.00	Low-inclined
Aegir	6	–1119.33	Mundilfari
S/2019 S 10	3	–1123.04	Mundilfari
Beli	4	–1121.76	Mundilfari
S/2020 S 25	3	–1115.85	Mundilfari
S/2023 S 33	3	–1116.27	Kari
S/2023 S 29	3	–1118.63	Mundilfari
S/2004 S 61	4	–1127.53	Mundilfari
S/2019 S 12	4	–1138.85	Mundilfari
Gerd	4	–1142.97	Phoebe
S/2019 S 13	3	–1144.92	Phoebe
S/2023 S 32	2	–1139.03	Mundilfari
S/2006 S 14	3	–1152.68	Mundilfari
Gunnlod	4	–1157.98	Mundilfari
S/2019 S 15	3	–1161.54	Mundilfari
S/2023 S 31	3	–1153.31	Mundilfari
S/2020 S 6	3	–1168.86	Mundilfari
S/2023 S 30	3	–1162.14	Low-inclined
S/2004 S 7	5	–1173.93	Mundilfari
S/2020 S 30	3	–1164.79	Kari
S/2006 S 3	5	–1174.76	Kari
S/2005 S 5	3	–1177.82	Mundilfari
S/2023 S 34	3	–1166.33	Mundilfari
S/2020 S 32	3	–1168.58	Mundilfari
Skrymir	4	–1185.15	Phoebe
S/2020 S 26	3	–1180.37	Mundilfari
S/2020 S 27	3	–1189.90	Low-inclined
S/2006 S 16	3	–1207.52	Mundilfari
S/2006 S 15	4	–1213.96	Mundilfari
S/2023 S 38	3	–1205.78	Mundilfari
S/2023 S 36	3	–1206.38	Mundilfari
S/2004 S 28	5	–1220.68	Mundilfari
S/2020 S 29	3	–1213.16	Mundilfari
S/2023 S 37	3	–1214.09	Phoebe
S/2020 S 8	3	–1228.12	Mundilfari
S/2023 S 35	3	–1215.99	Mundilfari
Alvaldi	6	–1232.19	Phoebe
Kari	6	–1231.01	Kari
S/2023 S 49	3	–1221.77	Mundilfari
S/2023 S 39	3	–1224.82	Mundilfari
S/2004 S 48	4	–1242.40	Mundilfari
Geirrod	4	–1251.14	Kari
S/2023 S 40	3	–1244.84	Mundilfari
Fenrir	4	–1260.25	Mundilfari
S/2023 S 41	3	–1246.28	Phoebe
S/2004 S 50	3	–1260.44	Mundilfari
S/2019 S 38	3	–1247.99	Mundilfari
S/2006 S 28	4	–1248.46	Phoebe
S/2006 S 17	4	–1264.58	Mundilfari
S/2004 S 49	4	–1264.25	Mundilfari
S/2023 S 42	3	–1251.98	Mundilfari
S/2020 S 28	3	–1261.08	Mundilfari
S/2019 S 17	4	–1291.39	Kari
Surtur	6	–1296.49	Mundilfari
S/2006 S 18	4	–1298.40	Mundilfari
S/2020 S 34	3	–1291.52	Mundilfari
S/2020 S 31	3	–1293.17	Mundilfari
Loge	6	–1311.83	Mundilfari
Ymir	22	–1315.16	Phoebe
S/2019 S 19	3	–1318.05	Kari
S/2019 S 18	3	–1327.06	Kari
S/2004 S 21	4	–1325.43	Kari
S/2004 S 39	4	–1336.17	Mundilfari
S/2020 S 37	3	–1321.82	Phoebe
S/2019 S 16	3	–1341.17	Mundilfari
S/2004 S 53	4	–1342.44	Mundilfari
S/2020 S 40	3	–1328.86	Mundilfari
S/2004 S 36	4	–1352.93	Kari
S/2023 S 45	3	–1338.11	Kari
S/2020 S 33	3	–1338.98	Mundilfari
S/2023 S 43	3	–1344.65	Mundilfari
Thiazzi	4	–1366.68	Mundilfari
S/2020 S 38	4	–1354.35	Mundilfari
S/2019 S 20	3	–1375.45	Kari
S/2006 S 19	4	–1389.33	Phoebe
S/2019 S 42	4	–1375.15	Mundilfari
S/2019 S 39	3	–1400.28	Mundilfari
S/2004 S 34	4	–1420.77	Mundilfari
S/2019 S 40	3	–1436.04	Mundilfari
S/2020 S 39	3	–1449.05	Mundilfari
S/2020 S 42	3	–1453.72	Mundilfari
S/2019 S 41	3	–1455.81	Mundilfari
Fornjot	6	–1494.03	Mundilfari
S/2023 S 5	3	–1476.73	Mundilfari
S/2004 S 51	4	–1519.43	Mundilfari
S/2020 S 10	3	–1527.22	Mundilfari
S/2023 S 46	3	–1508.36	Low-inclined
S/2020 S 41	3	–1511.10	Mundilfari
S/2020 S 9	4	–1534.97	Mundilfari
S/2006 S 29	3	–1558.48	Mundilfari
S/2019 S 44	3	–1572.74	Mundilfari
S/2004 S 26	5	–1603.95	Phoebe
S/2020 S 43	3	–1586.24	Mundilfari
S/2023 S 44	3	–1591.27	Mundilfari
S/2019 S 21	4	–1636.32	Mundilfari
S/2004 S 52	3	–1633.98	Mundilfari
S/2023 S 47	3	–1624.59	Mundilfari
S/2019 S 43	3	–1673.46	Mundilfari
S/2020 S 44	3	–1753.36	Mundilfari

Notes

1. May be a fragment of Phoebe, since it orbits at close proximity to Phoebe and could potentially be a part of the Phoebe subgroup.

See also

• List of natural satellites