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1338 Duponta
	Duponta seen at approx. 16 apmag in 2009
Discovery
Discovered by	L. Boyer
Discovery site	Algiers Obs.
Discovery date	4 December 1934
Designations
MPC designation	(1338) Duponta
Pronunciation	/djuːˈpɒntə/
Named after	Marc Dupont; (discoverer's nephew)
Alternative designations	1934 XA
Minor planet category	main-belt · (inner); Flora
Orbital characteristics
	Epoch 4 September 2017 (JD 2458000.5)
	Uncertainty parameter 0
Observation arc	82.42 yr (30,104 days)
Aphelion	2.5179 AU
Perihelion	2.0108 AU
Semi-major axis	2.2644 AU
Eccentricity	0.1120
Orbital period (sidereal)	3.41 yr (1,245 days)
Mean anomaly	102.88°
Mean motion	0° 17m 21.48s / day
Inclination	4.8170°
Longitude of ascending node	325.63°
Argument of perihelion	110.63°
Known satellites	1 (P: 17.57; D: 1.77 km)
Physical characteristics
Dimensions	7.470±0.114 km; 7.68±0.06 (derived); 7.875±0.062 km; 7.88 km (taken); 7.885 km
Synodic rotation period	3.85449±0.0003 h; 3.85453±0.00009 h; 3.85453±0.0003 h
Geometric albedo	0.2159; 0.2286±0.0274; 0.251±0.040
Spectral type	S (assumed)
Absolute magnitude (H)	12.30±0.03 (R) · 12.39±0.2 (R) · 12.6 · 12.7 · 12.75 · 12.798±0.064

1338 Duponta, provisional designation 1934 XA, is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 7.8 kilometers in diameter.

It was discovered on 4 December 1934, by French astronomer Louis Boyer at the Algiers Observatory in Algeria, North Africa.^[11] It was named after the discoverer's nephew, Marc Dupont.^[2] The asteroid's unnamed minor-planet moon was discovered in March 2007. It measures approximately 1.77 kilometers in diameter and has an orbital period of 17.57 hours.^[5]

Orbit and classification

Duponta is a member of the Flora family (402),^[3]^[4] a giant asteroid family and the largest family of stony asteroids in the main belt.^[12]^: 23 It orbits the Sun in the inner main belt at a distance of 2.0–2.5 AU once every 3 years and 5 months (1,245 days). Its orbit has an eccentricity of 0.11 and an inclination of 5° with respect to the ecliptic.^[1] The body's observation arc begins with its official discovery observation at Algiers in 1934.^[11]

Physical characteristics

Duponta is an assumed stony S-type asteroid, which agrees with the Flora family's overall spectral type.^[3]^[12]^: 23

Rotation period

In March 2007, a rotational lightcurve of Duponta was obtained from photometric observations by a collaboration of Czech (Ondřejov Observatory), Slovak (Modra Observatory), Australian and American astronomers. Lightcurve analysis gave a well-defined rotation period of 3.85453 hours with a brightness variation of 0.23 magnitude (U=3).^[5] Follow-up observations by Petr Pravec in 2007 and 2010, gave a concurring period of 3.85449 and 3.85453 hours with an amplitude of 0.26 and 0.23 magnitude, respectively (U=3/3).^[10]^[a]^[b]

Moon

During the photometric observations in 2007, it was also revealed that Duponta is a synchronous binary asteroid with a minor-planet moon orbiting it every 17.57(8) hours. Based on mutual eclipse and occultation events with a magnitude between 0.06 and 0.12, the binary system has a mean-diameter ratio of 0.23±0.02, which translates into a diameter of 1.77 kilometers for the satellite. The minor planet moon has received the provisional designation S/2007 (1338) 1. It has an estimated semi-major axis of 14 kilometers.^[3]^[5]^[6]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Duponta measures 7.470 and 7.875 kilometers in diameter and its surface has an albedo of 0.2286 and 0.251, respectively.^[7]^[8]

The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE data, that is, an albedo of 0.2159 and a diameter of 7.885 kilometers based on an absolute magnitude of 12.798.^[3]^[9]

Naming

This minor planet was named by the discoverer after his nephew Marc Dupont. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 122).^[2]

Notes

^ ^a ^b Pravec (2010) lightcurve plots – short and long period for (1338) Duponta, from online data published by the Ondrejov Asteroid Photometry Project. Summary figures at the LCDB
^ ^a ^b Pravec (2007) lightcurve plots – short and long period for (1338) Duponta, from online data published by the Ondrejov Asteroid Photometry Project. Summary figures at the LCDB

References

^ ^a ^b ^c ^d "JPL Small-Body Database Browser: 1338 Duponta (1934 XA)" (2017-05-06 last obs.). Jet Propulsion Laboratory. Retrieved 18 September 2017.
^ ^a ^b ^c Schmadel, Lutz D. (2007). "(1338) Duponta". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 109. doi:10.1007/978-3-540-29925-7_1339. ISBN 978-3-540-00238-3.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j "LCDB Data for (1338) Duponta". Asteroid Lightcurve Database (LCDB). Retrieved 18 September 2017.
^ ^a ^b "Asteroid 1338 Duponta – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
^ ^a ^b ^c ^d ^e Gajdos, S.; Kornos, L.; Vilagi, J.; Galad, A.; Pravec, P.; Stephens, R.; et al. (March 2007). "(1338) Duponta". Central Bureau Electronic Telegrams. 910 (910): 1. Bibcode:2007CBET..910....1G. Retrieved 18 September 2017.
^ ^a ^b ^c ^d Johnston, Robert (21 September 2014). "(1338) Duponta". johnstonsarchive.net. Retrieved 18 September 2017.
^ ^a ^b ^c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 18 September 2017.
^ ^a ^b ^c ^d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
^ ^a ^b ^c ^d Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 18 September 2017.
^ ^a ^b ^c ^d ^e Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kusnirák, P.; Hornoch, K.; et al. (March 2012). "Binary asteroid population. 2. Anisotropic distribution of orbit poles of small, inner main-belt binaries". Icarus. 218 (1): 125–143. Bibcode:2012Icar..218..125P. doi:10.1016/j.icarus.2011.11.026. Retrieved 18 September 2017.
^ ^a ^b "1338 Duponta (1934 XA)". Minor Planet Center. Retrieved 18 September 2017.
^ ^a ^b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.