2741 Valdivia

2741 Valdivia (prov. designation: 1975 XG) is a background asteroid from the central regions of the asteroid belt, approximately 11 kilometers (6.8 miles) in diameter. It was discovered on 1 December 1975, by Chilean astronomers Carlos Torres and Sergio Barros at the Cerro El Roble Station northwest of Santiago de Chile.[13] The asteroid was named after Spanish conquistador Pedro de Valdivia.[2]

2741 Valdivia
Shape model of Valdivia from its lightcurve
Discovery [1]
Discovered byC. Torres
S. Barros
Discovery siteCerro El Roble Stn.
Discovery date1 December 1975
Designations
(2741) Valdivia
Named after
Pedro de Valdivia [2]
(Spanish conquistador)
1975 XG · 1935 CM
1952 DJ2 · 1953 QS
1969 EB1 · 1969 FC
1973 FX1 · 1979 UA1
1990 FO3
main-belt · (middle) [3]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc81.74 yr (29,856 days)
Aphelion3.0836 AU
Perihelion2.1352 AU
2.6094 AU
Eccentricity0.1817
4.22 yr (1,540 days)
142.32°
0° 14m 1.68s / day
Inclination10.287°
151.13°
91.480°
Physical characteristics
Mean diameter
9.13±0.43 km[4]
10.73±0.64 km[5]
11.679±0.172 km[6][7]
17.52 km (calculated)[3]
4.096±0.0005 h[8]
4.096±0.001 h[9]
4.098±0.001 h[10]
8.191±0.0001 h[11]
  • (269.0°, −31.0°) (λ1/β1)[12]
  • (103.0°, −59.0°) (λ2/β2)[12]
0.10 (assumed)[3]
0.205±0.035[6]
0.2052±0.0350[7]
0.244±0.032[5]
0.404±0.066[4]
S/C [3]
11.764±0.002 (R)[8] · 11.80[4] · 11.9[1][3] · 12.00[5][7]

    Orbit and classification

    Valdivia is a non-family asteroid from the main belt's background population. It orbits the Sun in the central main-belt at a distance of 2.1–3.1 AU once every 4 years and 3 months (1,540 days). Its orbit has an eccentricity of 0.18 and an inclination of 10° with respect to the ecliptic.[1] The asteroid was first observed as 1935 CM at Uccle Observatory in February 1935, where the body's observation arc begins just a two weeks later, or more than 40 years before its official discovery observation at Cerro El Roble.[13]

    Naming

    This minor planet was named after Spanish conquistador Pedro de Valdivia (1502–1553), who conquered Chile with a small expedition corps after he served under Francisco Pizarro in Peru. Valdivia founded the cities Santiago (1541) and Concepción (1550) and became Chile's first royal governor.[2] The city of Valdivia in southern Chile is also named after him. The official naming citation was published by the Minor Planet Center on 26 March 1986 (M.P.C. 10546).[14]

    Physical characteristics

    Rotation period

    In August 2016, the so-far best-rated rotational lightcurve of Valdivia was obtained by the Spanish amateur astronomer group OBAS. Lightcurve analysis gave a rotation period of 4.098 hours with a brightness variation of 0.25 magnitude (U=3).[10] Previously, in May 2003, photometric observations made by Donald P. Pray at the Carbuncle Hill Observatory (912) near Providence, Rhode Island, gave a synodic period of 4.096 hours and an amplitude of 0.40 in magnitude (U=2+).[9] In addition astronomers at the Palomar Transient Factory found a period of 4.096 hours with an amplitude of 0.28 om May 2011 (U=2),[8] and French amateur astronomer René Roy obtained a period of 8.1922 hours (twice the period solution) with an amplitude of 0.36 (U=2).[11]

    Poles

    In 2016, an international study modeled a lightcurve with a concurring period of 4.09668±0.00005 hours and found two spin axes of (269.0°, −31.0°) and (103.0°, −59.0°) in ecliptic coordinates (λ, β) (U=n.a.).[12]

    Diameter and albedo

    According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Valdivia measures between 9.13 and 11.679 kilometers in diameter and its surface has an albedo between 0.205 and 0.404,[4][6][7] while the Japanese Akari satellite found an albedo of 0.244 and a diameter of 10.73 kilometers.[5] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 – a compromise value between the carbonaceous (0.057) and stony (0.20) asteroids – and calculates a diameter of 17.52 kilometers based on an absolute magnitude of 11.9.[3]

    References
    1. "JPL Small-Body Database Browser: 2741 Valdivia (1975 XG)" (2016-11-23 last obs.). Jet Propulsion Laboratory. Retrieved 18 September 2017.
    2. Schmadel, Lutz D. (2007). "(2741) Valdivia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 224. doi:10.1007/978-3-540-29925-7_2742. ISBN 978-3-540-00238-3.
    3. "LCDB Data for (2741) Valdivia". Asteroid Lightcurve Database (LCDB). Retrieved 18 September 2017.
    4. Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 18 September 2017.
    5. Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
    6. 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 18 September 2017.
    7. 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.
    8. Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 18 September 2017.
    9. Pray, Donald P. (March 2004). "Lightcurve analysis of asteroids 1225, 1301, 2134, 2741, and 3974" (PDF). Minor Planet Bulletin. 31 (1): 6–8. Bibcode:2004MPBu...31....6P. ISSN 1052-8091. Retrieved 18 March 2020.
    10. Brines, Pedro; Lozano, Juan; Rodrigo, Onofre; Fornas, A.; Herrero, David; Mas, Vicente; et al. (April 2017). "Sixteen Asteroids Lightcurves at Asteroids Observers (OBAS) - MPPD: 2016 June-November" (PDF). Minor Planet Bulletin. 44 (2): 145–149. Bibcode:2017MPBu...44..145B. ISSN 1052-8091.
    11. Behrend, Raoul. "Asteroids and comets rotation curves – (2741) Valdivia". Geneva Observatory. Retrieved 18 September 2017.
    12. Hanuš, J.; Ďurech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: A108. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441. ISSN 0004-6361.
    13. "2741 Valdivia (1975 XG)". Minor Planet Center. Retrieved 18 September 2017.
    14. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 18 September 2017.
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