astro.wikisort.org - Asteroid

24101 Cassini, provisional designation 1999 VA₉, is an eccentric background asteroid from the middle region of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 9 November 1999, by American amateur astronomer Charles Juels at the Fountain Hills Observatory (678) in Arizona, United States.[8] It was named after Italian–French astronomer Giovanni Cassini.

24101 Cassini

Discovery [1]
Discovered by	C. W. Juels
Discovery site	Fountain Hills Obs.
Discovery date	9 November 1999
Designations
MPC designation	(24101) Cassini
Named after	Giovanni Cassini (Italian astronomer)[2]
Alternative designations	1999 VA9 · 1926 XH 1926 YB · 1986 RS16 1986 TM15
Minor planet category	main-belt · (middle) [3] background
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	90.18 yr (32,937 days)
Aphelion	3.4620 AU
Perihelion	1.8278 AU
Semi-major axis	2.6449 AU
Eccentricity	0.3089
Orbital period (sidereal)	4.30 yr (1,571 days)
Mean anomaly	29.894°
Mean motion	0° 13m 44.76s / day
Inclination	15.474°
Longitude of ascending node	176.58°
Argument of perihelion	255.81°
Physical characteristics
Mean diameter	7.051±0.352 km[4][5] 11.05 km (calculated)[3]
Synodic rotation period	3.986±0.001 h[6][lower-alpha 1]
Geometric albedo	0.10 (assumed)[3] 0.2458±0.0529[4] 0.246±0.053[5]
Spectral type	S/C [3]
Absolute magnitude (H)	12.9[1][3][4] · 13.05±0.23[7]

Orbit and classification

Cassini is a non-family from the main belt's background population. It orbits the Sun in the central asteroid belt at a distance of 1.8–3.5 AU once every 4 years and 4 months (1,571 days). Its orbit has an eccentricity of 0.31 and an inclination of 15° with respect to the ecliptic.[1]

In December 1926, the asteroid was first identified as 1926 XH at Heidelberg Observatory in Germany. The body's observation arc begins 7 years prior to its official discovery observation, with a precovery taken at La Silla Observatory in March 1992.[8]

Physical characteristics

Lightcurve

In February 2009, two rotational lightcurves of Cassini were obtained from photometric observations by Italian astronomer Silvano Casulli, and at the private Shed of Science Observatory (H39) in Minnesota, United States. Lightcurve analysis gave a well-defined, concurring rotation period of 3.986 hours with a brightness variation of 0.12 magnitude (U=3/-3).[6][lower-alpha 1]

Diameter and albedo

According to observations carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Cassini measures 7.051 kilometer in diameter and its surface has an albedo of 0.2458.[4]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 – a compromise value between the brighter stony (0.20) and darker carbonaceous (0.057) asteroids of the 2.6 to 2.7 AU-region of the asteroid belt – and correspondingly, calculates a larger diameter of 11.05 kilometers, as the lower a body's albedo (reflectivity), the larger its diameter for a given absolute magnitude (brightness).[3]

Naming

This minor planet was named in honor of Italian-born French astronomer Giovanni Cassini (1625–1712), who was the first director of the Paris Observatory from 1671 until his death. He discovered the four moons of Saturn – Iapetus, Rhea, Tethys and Dione – the major gap in its rings, known as Cassini Division, and was the first to write down observations of the zodiacal light. The Cassini–Huygens spacecraft is named after him and Christiaan Huygens.[2]

The lunar and Martian craters Cassini are also named in his honor. The approved naming citation was published by the Minor Planet Center on 21 September 2002 (M.P.C. 46684).[9]

References

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 (20001)-(25000) – Minor Planet Center
• 24101 Cassini at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 24101 Cassini at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (24101) Cassini

(24101) Cassini ist ein Asteroid des Hauptgürtels, der am 9. November 1999 vom US-amerikanischen Amateurastronomen Charles W. Juels am Fountain-Hills-Observatorium (Sternwarten-Code 678) in Fountain Hills im US-Bundesstaat Arizona entdeckt wurde.

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- [en] 24101 Cassini

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