astro.wikisort.org - Asteroid

1494 Savo, provisional designation 1938 SJ, is a stony background asteroid from the inner region of the asteroid belt, approximately 8 kilometers in diameter. Discovered by astronomer Yrjö Väisälä at the Turku Observatory in 1938, the asteroid was later named after the Finnish region of Savonia.[2]

1494 Savo

Shape of Savo modelled from its lightcurve
Discovery[1]
Discovered by	Y. Väisälä
Discovery site	Turku Obs.
Discovery date	16 September 1938
Designations
MPC designation	(1494) Savo
Named after	Savonia[2] (Finnish region)
Alternative designations	1938 SJ · 1925 RL 1938 SG1 · 1948 VR 1951 SV · 1953 GD 1966 HB · 1976 HZ
Minor planet category	main-belt · (inner)[3] background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	78.50 yr (28,673 days)
Aphelion	2.4777 AU
Perihelion	1.9019 AU
Semi-major axis	2.1898 AU
Eccentricity	0.1315
Orbital period (sidereal)	3.24 yr (1,184 days)
Mean anomaly	114.29°
Mean motion	0° 18m 14.76s / day
Inclination	2.4560°
Longitude of ascending node	195.02°
Argument of perihelion	184.32°
Physical characteristics
Dimensions	7.80±0.22 km[5] 7.804±0.219 km[5] 9.23±0.43 km[6] 10.30 km (calculated)[3]
Synodic rotation period	5.35011±0.00028 h[lower-alpha 1] 5.35020±0.00005 h[7] 5.35031±0.00005 h[7] 5.35059±0.00001 h[8] 5.35059±0.00005 h[9] 5.35062±0.00005 h[7]
Geometric albedo	0.173±0.017[6] 0.20 (assumed)[3] 0.349±0.061[5]
Spectral type	SMASS = Sa[1] · S[3]
Absolute magnitude (H)	12.08±0.24[10] · 12.30[1][3][5] · 12.70[6]

Discovery

Savo was discovered on 16 September 1938, by Finnish astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory near Turku, Finland.[11] Two nights later, it was independently discovered by German astronomer Arno Arthur Wachmann at the Bergedorf Observatory in Hamburg.[2] However, the Minor Planet Center only acknowledges the first discoverer. The asteroid was first identified as 1925 RL at the Crimean Simeiz Observatory in September 1929, or nine years before its official discovery observation.[11]

Orbit and classification

Savo is an asteroid of the main belt's background population that does not belong to any known asteroid family.[4] It orbits the Sun in the inner asteroid belt at a distance of 1.9–2.5 AU once every 3 years and 3 months (1,184 days). Its orbit has an eccentricity of 0.13 and an inclination of 2° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Turku in September 1938.[11]

Physical characteristics

In the SMASS classification, Savo is an Sa-subtype that transitions from the stony S-type to the A-type asteroids.[1]

Rotation period

In August 2006, a rotational lightcurve of Savo was obtained from photometric observations by Czech astronomer Petr Pravec at Ondřejov Observatory. Lightcurve analysis gave a well-defined rotation period of 5.35011 hours with a brightness amplitude of 0.52 magnitude (U=3), indicative for a non-spherical shape.[lower-alpha 1] Follow up observations at the Calvin College Observatory (H62) in 2007 and 2008, gave three nearly identical periods of 5.35020, 5.35031 and 5.35062 hours with an amplitude between 0.44 and 0.63 (U=3/3/3-).[7]

Poles

The asteroid's lightcurve has also been modeled twice. In 2011, the first modelling used photometric data from the AstDyS database and the Uppsala Asteroid Photometric Catalogue, and found two spin axis of (248.0°, −68.0°) and (83.0°, −66.0°) in ecliptic coordinates (λ, β).[9] A refined modeling in 2016, using the Lowell Photometric Database gave two poles of (50.0°, −65.0°) and (233.0°, −68.0°) in ecliptic coordinates.[8] Also, both studies found a concurring period of 5.35059 hours.[9][8]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Savo measures between 7.80 and 9.23 kilometers in diameter and its surface has an albedo between 0.173 and 0.349.[5][6] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 10.30 kilometers based on an absolute magnitude of 12.3.[3]

Naming

This minor planet was named after Finnish historical province of Savonia.[2] The official naming citation was published by the Minor Planet Center in January 1956 (M.P.C. 1350).[12]

Notes

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1494 Savo at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1494 Savo at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (1494) Savo

(1494) Savo ist ein Asteroid des Hauptgürtels, der am 16. September 1938 von dem finnischen Astronomen Yrjö Väisälä in Turku entdeckt wurde.

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- [en] 1494 Savo

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