UPSA Object Registry

Registry · solar system

Helene

Natural satellite JPL Horizons

Mass: 0.002547 1e22 kg
Density: 1.5 g cm^-3
Orbital period: 2.7369 d
Geometric albedo: 0.6

Also known as

2 identifiers

Horizons 612SXII

Recorded parameters

9 quantities with a single published value

Parameter	Value	Unit	Uncertainty	As published	Source	Reference
Mass	0.002547	1e22 kg		Mass (10^22 g )	JPL Horizons	JPL Horizons on-line ephemeris system
Density	1.5	g cm^-3		Density (g cm^-3)	JPL Horizons	JPL Horizons on-line ephemeris system
Orbital period	2.736915	d		Orbital period	JPL Horizons	JPL Horizons on-line ephemeris system
Geometric albedo	0.6			Geometric Albedo	JPL Horizons	JPL Horizons on-line ephemeris system
GM	0.00047574	km^3/s^2		GM (km^3/s^2)	JPL Horizons	JPL Horizons on-line ephemeris system
Eccentricity e	0.0071	e		Eccentricity, e	JPL Horizons	JPL Horizons on-line ephemeris system
Inclination i deg	0.213	deg		Inclination, i (deg)	JPL Horizons	JPL Horizons on-line ephemeris system
Radius km mean	16	mean		Radius (km),mean	JPL Horizons	JPL Horizons on-line ephemeris system
Semi major axis a km	377.42	km		Semi-major axis, a (km)	JPL Horizons	JPL Horizons on-line ephemeris system

Provenance

where this card came from

Archive	Read at (UTC)	Record
JPL Horizons	2026-08-14 17:09	open at source

Machine-readable: /api/v1/object/helene · Registry entry updated 2026-08-14.