astro.wikisort.org - Asteroid

3800 Karayusuf, provisional designation 1984 AB, is a Mars-crossing asteroid and suspected binary system from inside the asteroid belt, approximately 2.5 kilometers (1.6 miles) in diameter. It was discovered on 4 January 1984, by American astronomer Eleanor Helin at the Palomar Observatory in California.[1] The S/L-type asteroid has a short rotation period of 2.2 hours.[3] It was named after Syrian physician Alford Karayusuf, a friend of the discoverer.[1]

3800 Karayusuf

Discovery [1]
Discovered by	E. F. Helin
Discovery site	Palomar Obs.
Discovery date	4 January 1984
Designations
MPC designation	(3800) Karayusuf
Named after	Alford Karayusuf [1] (discoverer's friend)
Alternative designations	1984 AB · 1975 XL4
Minor planet category	Mars-crosser [1][2][3]
Orbital characteristics [2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	42.47 yr (15,513 d)
Aphelion	1.6974 AU
Perihelion	1.4584 AU
Semi-major axis	1.5779 AU
Eccentricity	0.0757
Orbital period (sidereal)	1.98 yr (724 d)
Mean anomaly	349.96°
Mean motion	0° 29m 50.28s / day
Inclination	14.847°
Longitude of ascending node	95.451°
Argument of perihelion	115.76°
Physical characteristics
Mean diameter	2.51±0.25 km[4]
Synodic rotation period	2.2319±0.0001 h[5][lower-alpha 1]
Geometric albedo	0.281[4]
Spectral type	SMASS = S [2] · S [3][6] L (SDSS-MOC)[7][8][9]
Absolute magnitude (H)	14.81±0.94[9] 15.00[1][2][3][4][10][11] 15.40[6]

Orbit and classification

Karayusuf is a Mars-crossing asteroid, a dynamically unstable group between the main-belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU. It orbits the Sun at a distance of 1.46–1.70 AU once every 2 years (724 days; semi-major axis of 1.58 AU). Its orbit has an eccentricity of 0.08 and an inclination of 15° with respect to the ecliptic. On 11 June 1938, Karayusuf passed 0.0151 AU (2,260,000 km; 1,400,000 mi) from Mars.[2]

The body's observation arc begins with its first observations as 1975 XL₄ at Crimea–Nauchnij in December 1975, almost 12 years prior to its official discovery observation at Palomar.[1]

Naming

This minor planet was named after Syrian physician Alford Karayusuf, a supporter of the Near-earth asteroid research projects at JPL and a leader of the World Space Foundation's program of Solar System exploration.[1] The official naming citation was published by the Minor Planet Center on 2 November 1990 (M.P.C. 17221).[12] The main-belt asteroid 5255 Johnsophie, also discovered by Helin, was named after Alford Karayusuf's children, John and Sophie (also see the asteroid's citation).

Physical characteristics

In the SMASS classification, Karayusuf is a common, stony S-type asteroid.[2] The asteroid has also been characterized as an L-type asteroid by the Sloan Digital Sky Survey and Pan-STARRS' photometric survey.[7][8][9]

Rotation period

In March 2008, a rotational lightcurve of Karayusuf was obtained from photometric observations by Brian Warner at his Palmer Divide Observatory in Colorado. Lightcurve analysis gave a well-defined rotation period of 2.2319±0.0001 hours with a rather small brightness amplitude of 0.15 magnitude (U=3).[5][lower-alpha 1] The body's rotation is close to the threshold-period of that of a fast rotator, which would fly apart if they were not composed of a solid, monolithic structure.

Follow-up observations by Warner in 2010, 2014 and 2018 gave similar results.[13][14][lower-alpha 2] The asteroid was also observed by Brian Skiff (2.225 h) and William Ryan (2.23 h) in 2018.[lower-alpha 3]

Binary candidate

During Brian Warner's photometric observations, two possible mutual eclipsing/occultation events were observed, indicating that Karayusuf is a binary asteroid with a satellite in its orbit. The data, however, was insufficient to calculate a rotation period.[5] In 2010 and in 2014, when observing conditions had a nearly identical phase angle, no evidence of an orbiting minor-planet moon was found.[13][14] The results of the 2018-observation have not yet been published.[lower-alpha 2]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Karayusuf measures 2.51 kilometers in diameter and its surface has an albedo between 0.281,[4] while other NEOWISE observations gave a diameter of 1.624 kilometers with a not very plausible albedo of 0.657.[10][11] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a stony asteroid of 0.20 and calculates a diameter of 2.97 kilometers based on an absolute magnitude of 15.0.[3]

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
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 3800 Karayusuf at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 3800 Karayusuf at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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- [en] 3800 Karayusuf

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[ru] (3800) Караюсуф

(3800) Караюсуф (лат. Karayusuf) — астероид, относящийся к группе астероидов пересекающих орбиту Марса. Принадлежит к светлому спектральному классу S. Он был обнаружен 4 января 1984 года американским астрономом Элеанор Хелин в Паломарской обсерватории и назван в честь султана Кара Юсуфа[1].

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