2091 Sampo

2091 Sampo (provisional designation 1941 HO), is a stony Eos asteroid and relatively slow rotator from the outer region of the asteroid belt, approximately 30 kilometers in diameter. It was discovered on 26 April 1941, by Finnish astronomer Yrjö Väisälä at Turku Observatory, Finland, and named after Sampo from Finnish mythology.^[10]

2091 Sampo

Discovery[1]
Discovered by	Y. Väisälä
Discovery site	Turku Obs.
Discovery date	26 April 1941
Designations
MPC designation	(2091) Sampo
Named after	Sampo (Finnish mythology)[2]
Alternative designations	1941 HO · 1931 MG 1938 UF1 · 1951 GA1 1952 LB · 1956 EP 1971 BH1 · 1978 NB A924 BB
Minor planet category	main-belt · (outer) Eos[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	93.06 yr (33,989 days)
Aphelion	3.1985 AU
Perihelion	2.8300 AU
Semi-major axis	3.0143 AU
Eccentricity	0.0611
Orbital period (sidereal)	5.23 yr (1,911 days)
Mean anomaly	359.61°
Mean motion	0° 11m 17.88s / day
Inclination	11.378°
Longitude of ascending node	114.53°
Argument of perihelion	318.84°
Physical characteristics
Dimensions	23.024±0.474 km[5] 23.493±0.240 km[6] 30.25 km (derived)[3] 30.48±1.3 km[7] 35.47±0.45 km[8]
Synodic rotation period	71.34±0.05 h[9]
Geometric albedo	0.118±0.003[8] 0.1218 (derived)[3] 0.1582±0.014[7] 0.2683±0.0325[6] 0.277±0.019[5]
Spectral type	S[3]
Absolute magnitude (H)	10.2[6][7][8] · 10.5[1][3]

Orbit and classification

Sampo is a member of the Eos family (606), the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids.^{[4][11]: 23} It orbits the Sun in at a distance of 2.8–3.2 AU once every 5 years and 3 months (1,911 days). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic.^[1]

Physical characteristics

The S-type asteroid measures between 23.0 and 35.5 kilometers in diameter, and its surface has an albedo between 0.118 and 0.277, according to the surveys carried out by IRAS, Akari, and NEOWISE.^[5][6][7][8]

A rotational lightcurve of Sampo was obtained from photometric observations made by astronomers René Roy, Laurent Bernasconi and Stéphane Charbonnelat in March 2003. It gave a potentially long rotation period of 71.34±0.05 hours with a brightness variation of 0.38 magnitude (U=2).^[9]

Naming

This minor planet was named after the wonder-object Sampo from Finnish mythology. It is mentioned in the national oral folklore and mythology epic, Kalevala, after which the minor planet 1454 Kalevala is named. Sampo was to produce every kind of fortune. When Kalevala and Pohjola (also see 3606 Pohjola) were fighting for its possession it broke into pieces.^[2] The official naming citation was published by the Minor Planet Center on 1 August 1980 (M.P.C. 5450).^[12]