Irregular moons of Saturn -- Bergelmir

For notes, see https://tilmanndenk.de/outersaturnianmoons/bergelmir/#1

23 Oct 2018 / TD


	Overview Table
Moon name	Bergelmir
Saturn range	19e6	km
Orbit period	2.8	years
Orbit direction	retrograde
Size ~	5	km
Rotation period	08	08	hh:mm
Discovery year	2004

(A)	Designations and discovery circumstances
(A1)	Moon name	Bergelmir
(A2)	Moon abbrev. (TD)	Ber
(A3)	IAU number	Saturn XXXVIII
(A4)	Provisional designation	S/2004 S 15
(A5)	SPICE ID	638
(A6)	Also-used label	S38
(A7)	First observation date	12 Dec 2004
(A7)	Announcement date	04 May 2005
(A7)	IAU circular announcement no.	8523
(A8)	Discoverers	Jewitt, et al.

(B)	Orbit parameters
(B1)	Orbit direction	retrograde
(B2)	Group member	Norse
(B3)	Dynamical family	Bergelmir
(B4)	Periapsis range	16.59e6	km
(B5)	Semi-major axis	19.34e6	km
(B6)	Apoapsis range	22.09e6	km
(B7)	Semi-major axis	321	R_Saturn
(B8)	Semi-major axis	0.129	au
(B9)	Semi-major axis	0.30	R_Hill
(B10)	Orbit eccentricity	0.14	
(B11)	Orbit inclination	158.6	°
(B12)	Inclination supplemental angle	21.4	°
(B13)	Orbital period	1006	d
(B14)	Orbital period	2	9	0.25	y:m:w
(B15)	Mean orbit velocity	1.40	km/s

(C)	Physical parameters
(C1)	Mean size ~	5	-1	+1.5	km
(C2)	Mean radius ~	2.5	km
(C3)	Equatorial circumference ~	15	km
(C4)	Minimum equatorial axes ratio	1.13
(C5)	Axes radii (a x b x c) ~	unknown
(C5)	
(C6)	Mass ~	3e13	kg
(C7)	Mean density (?)	0.5	g/cm^3
(C8)	Surface escape velocity ~	3	km/h
(C9)	Rotation period	8.13	h
(C9)	Rotation period error	0.09	h
(C9)	Spin rate	2.95	d^(-1)
(C10)	Spin direction	unknown
(C11)	Seasons	unknown
(C12)	Pole direction (ecliptic longitude λ)	unknown
(C12)	Pole direction (ecliptic latitude β)	unknown
(C13)	Pole direction (geocentric RA)	unknown
(C13)	Pole direction (geocentric Dec)	unknown
(C14)	Absolute visual magnitude ~	15.2	mag
(C15)	Apparent visual magnitude from Earth	24.2	mag
(C16)	Best apparent magnitude for Cassini	15.9	mag
(C17)	Spectral slope		
(C17)	B-R color index ~	1.10	
(C18)	Albedo (?)	0.06	
(C19)	Hill sphere radius ~	450	km
(C20)	Hill sphere radius ~	175	r_Ber