Irregular moons of Saturn -- Fornjot

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

23 Oct 2018 / TD


	Overview Table
Moon name	Fornjot
Saturn range	25e6	km
Orbit period	4.1	years
Orbit direction	retrograde
Size ~	6	km
Rotation period	9		h ?
Discovery year	2004

(A)	Designations and discovery circumstances
(A1)	Moon name	Fornjot
(A2)	Moon abbrev. (TD)	For
(A3)	IAU number	Saturn XLII
(A4)	Provisional designation	S/2004 S 8
(A5)	SPICE ID	642
(A6)	Also-used label	S42
(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	Ymir
(B4)	Periapsis range	19.92e6	km
(B5)	Semi-major axis	25.15e6	km
(B6)	Apoapsis range	30.38e6	km
(B7)	Semi-major axis	417	R_Saturn
(B8)	Semi-major axis	0.168	au
(B9)	Semi-major axis	0.38	R_Hill
(B10)	Orbit eccentricity	0.21	
(B11)	Orbit inclination	170.4	°
(B12)	Inclination supplemental angle	9.6	°
(B13)	Orbital period	1494	d
(B14)	Orbital period	4	1	0.5	y:m:w
(B15)	Mean orbit velocity	1.23	km/s

(C)	Physical parameters
(C1)	Mean size ~	6	-1	+1.5	km
(C2)	Mean radius ~	2.9	km
(C3)	Equatorial circumference ~	20	km
(C4)	Minimum equatorial axes ratio	1.11
(C5)	Axes radii (a x b x c) ~	unknown
(C5)	
(C6)	Mass ~	5e13	kg
(C7)	Mean density (?)	0.5	g/cm^3
(C8)	Surface escape velocity ~	4	km/h
(C9)	Rotation period	7 or 9.5	h ?
(C9)	Rotation period error	--	
(C9)	Spin rate	2.5 or 3.4	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 ~	14.9	mag
(C15)	Apparent visual magnitude from Earth	24.6	mag
(C16)	Best apparent magnitude for Cassini	16.4	mag
(C17)	Spectral slope		
(C17)	B-R color index ~	1.40	
(C18)	Albedo (?)	0.06	
(C19)	Hill sphere radius ~	620	km
(C20)	Hill sphere radius ~	210	r_For