11665 Dirichlet

11665 Dirichlet
Discovery
Discovered by	P. G. Comba
Discovery site	Prescott Obs.
Discovery date	14 April 1997
Designations
MPC designation	(11665) Dirichlet
Named after	Peter Gustav Lejeune Dirichlet; (German mathematician)
Alternative designations	1997 GL28
Minor planet category	main-belt · (outer); Griqua
Orbital characteristics
	Epoch 27 April 2019 (JD 2458600.5)
	Uncertainty parameter 0
Observation arc	23.97 yr (8,756 d)
Aphelion	3.7625 AU
Perihelion	2.7963 AU
Semi-major axis	3.2794 AU
Eccentricity	0.1473
Orbital period (sidereal)	5.94 yr (2,169 d)
Mean anomaly	298.55°
Mean motion	0° 9m 57.6s / day
Inclination	15.787°
Longitude of ascending node	215.21°
Argument of perihelion	309.39°
TJupiter	3.0980
Physical characteristics
Mean diameter	6.803±0.358 km
Geometric albedo	0.087±0.014
Absolute magnitude (H)	14.1

11665 Dirichlet, provisional designation 1997 GL₂₈, is a Griqua asteroid and a 2:1 Jupiter librator from the outermost regions of the asteroid belt, approximately 6.8 kilometers (4 miles) in diameter. It was discovered on 14 April 1997, by astronomer Paul Comba at the Prescott Observatory in Arizona, United States. The asteroid was named after German mathematician Peter Gustav Lejeune Dirichlet.^[1]

Orbit and classification

Dirichlet is a Griqua asteroid, a small dynamical group of asteroids located in the otherwise sparsely populated Hecuba gap (2:1 resonance with Jupiter), which is one of the largest Kirkwood gaps in the asteroid belt.^[3]^[4] It orbits the Sun at a distance of 2.8–3.8 AU once every 5 years and 11 months (2,169 days; semi-major axis of 3.28 AU). Its orbit has an eccentricity of 0.15 and an inclination of 16° with respect to the ecliptic.^[2] The body's observation arc begins prior to its official discovery observation with a precovery taken by Spacewatch in October 1994.^[1]

This minor planet was named after German mathematician Peter Gustav Lejeune Dirichlet (1805–1859), who was the successor of Carl Friedrich Gauss and the predecessor of Bernhard Riemann at the University of Göttingen. His contributions include the first rigorous proof that the Fourier series converges. The official naming citation was published by the Minor Planet Center on 23 November 1999 (M.P.C. 36951).^[7]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Dirichlet measures 6.8 kilometers in diameter and its surface has an albedo of 0.09.^[5]^[6] As of 2018, no rotational lightcurve of Dirichlet has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.^[2]^[8]

^ ^a ^b ^c ^d ^e ^f "11665 Dirichlet (1997 GL28)". Minor Planet Center. Retrieved 4 December 2018.
^ ^a ^b ^c ^d ^e "JPL Small-Body Database Browser: 11665 Dirichlet (1997 GL28)" (2018-10-16 last obs.). Jet Propulsion Laboratory. Retrieved 4 December 2018.
^ ^a ^b Roig, F.; Nesvorný, D.; Ferraz-Mello, S. (September 2002). "Asteroids in the 2 : 1 resonance with Jupiter: dynamics and size distribution [ Erratum: 2002MNRAS.336.1391R ]". Monthly Notices of the Royal Astronomical Society. 335 (2): 417–431. Bibcode:2002MNRAS.335..417R. doi:10.1046/j.1365-8711.2002.05635.x.
^ ^a ^b "Asteroid (11665) Dirichlet – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 4 December 2018.
^ ^a ^b ^c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 4 December 2018.
^ ^a ^b "Asteroid 11665 Dirichlet". Small Bodies Data Ferret. Retrieved 4 December 2018.
^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 December 2018.
^ "LCDB Data for (11665) Dirichlet". Asteroid Lightcurve Database (LCDB). Retrieved 4 December 2018.