1170 Siva

1170 Siva

Modelled shape of Siva from its lightcurve
Discovery[1]
Discovered by	E. Delporte
Discovery site	Uccle Obs.
Discovery date	29 September 1930
Designations
MPC designation	(1170) Siva
Named after	Shiva (Hindu deity)[2]
Alternative designations	1930 SQ
Minor planet category	Mars-crosser[3][4] Phocaea[5]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc	85.19 yr (31,116 days)
Aphelion	3.0245 AU
Perihelion	1.6291 AU
Semi-major axis	2.3268 AU
Eccentricity	0.2998
Orbital period (sidereal)	3.55 yr (1,296 days)
Mean anomaly	94.741°
Mean motion	0° 16m 39.72s / day
Inclination	22.184°
Longitude of ascending node	0.9218°
Argument of perihelion	59.391°
Earth MOID	0.7263 AU
Mars MOID	0.3760 AU
Physical characteristics
Dimensions	7.68±2.18 km[6] 10.37±0.8 km (IRAS:2)[7] 12.13±0.89 km[8]
Synodic rotation period	3.5 h[9] 4.98 h[a] 5.22±0.01 h[10]
Geometric albedo	0.128±0.020[8] 0.1751±0.032 (IRAS:2)[7] 0.40±0.16[6]
Spectral type	B–V = 0.864[1] U–B = 0.452[1] Tholen = S[1] · S[3][11]
Absolute magnitude (H)	12.00[11] · 12.18[6] · 12.43[1][3][7][8]

1170 Siva, provisional designation 1930 SQ, is a stony Phocaea asteroid and large Mars-crosser from the innermost regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 29 September 1930, by Belgian astronomer Eugène Delporte at Uccle Observatory in Belgium, and later named after the Hindu deity Shiva.^[2][4]

Orbit and classification

Siva is a Mars-crossing asteroid, as it crosses the orbit of Mars at 1.666 AU. It is also a member of the Phocaea family (701).^[5] It orbits the Sun at a distance of 1.6–3.0 AU once every 3 years and 7 months (1,296 days). Its orbit has an eccentricity of 0.30 and an inclination of 22° with respect to the ecliptic.^[1] Siva was first observed at the Japanese Kwasan Observatory, 3 days prior to is discovery. The body's observation arc begins at Uccle, two weeks after its official discovery observation.^[4]

Naming

This minor planet is named after Shiva, a Hindu deity often depicted with a third eye on his forehead and with a snake around his neck.^[2] Naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 109).^[2]

Physical characteristics

In the Tholen taxonomy, Siva is a stony S-type asteroid.^[1]

Rotation period

Only fragmentary lightcurves of Siva have been obtained since 2001. They gave a rotation period between 3.5 and 5.22 hours with a small change in brightness of 0.04 to 0.1 magnitude (U=1/n.a./1).^[9][10][a] As of 2017, no secure period has been published.^[3]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Siva measures between 7.68 and 12.13 kilometers in diameter, and its surface has an albedo between 0.128 and 0.40.^[6][7][8] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.1751 and a diameter of 10.37 kilometers with an absolute magnitude of 12.43.^[3] Siva belongs to the brightest known Mars-crossers.^[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
• 1170 Siva at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1170 Siva at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

This page was last edited on 14 January 2024, at 21:30