1511 Daléra

1511 Daléra
Discovery [1]
Discovered by L. Boyer
Discovery site Algiers Observatory
Discovery date 22 March 1939
Designations
MPC designation 1511 Dalera
Named after
 Paul Daléra
(friend of discoverer)[2]
1939 FB · 1928 DB
1954 LM
main-belt · (inner) [3]
Orbital characteristics [1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 88.05 yr (32159 days)
Aphelion 2.6137 AU (391.00 Gm)
Perihelion 2.1017 AU (314.41 Gm)
2.3577 AU (352.71 Gm)
Eccentricity 0.10858
3.62 yr (1322.3 d)
126.80°
0° 16m 20.1s / day
Inclination 4.0687°
81.738°
97.344°
Earth MOID 1.10888 AU (165.886 Gm)
Jupiter MOID 2.35349 AU (352.077 Gm)
Jupiter Tisserand parameter 3.542
Physical characteristics
Dimensions 15.47 km (IRAS)[1]
7.15 km (calculated)[3]
12±5 km (convert. mag.)[4]
Mean radius
 7.735±1.6 km
3.880 h (0.1617 d)[1][5][6]
4.2227±0.0011 h[7]
0.0614±0.037 (IRAS)[1]
0.20 (assumed)[3]
S [3]
12.8 (IRAS)[1]
13.09 (transformed)[3][lower-alpha 1]

    1511 Daléra, provisional designation 1939 FB, is a stony asteroid from the inner regions of the asteroid belt, about 8 kilometers in diameter. It was discovered by French astronomer Louis Boyer at the Algerian Algiers Observatory, North Africa, on 22 March 1939.[8]

    The S-type asteroid orbits the Sun at a distance of 2.1–2.6 AU once every 3 years and 7 months (1,322 days). Its orbit shows an eccentricity of 0.11 and is tilted by 4 degrees to the plane of the ecliptic. It has a rotation period of 3.9 and 4.2 hours, determined by independent observations in 2015, respectively.[5][6][7]

    Based on NASA's magnitude-to-diameter conversion table, and on an absolute magnitude of 12.8, its diameter could be anywhere between 7 and 17 kilometers, assuming an albedo in the range of 0.05 to 0.25.[4] Data from the Infrared Astronomical Satellite, IRAS, gave a large diameter of 15 kilometers, based on a corresponding low albedo of 0.06, which is typical for dark asteroids with a carbonaceous composition.[3] However, the Collaborative Asteroid Lightcurve Link (CALL) calculates the body's diameter to be much smaller, about 7 kilometers in diameter, using a transformed absolute magnitude of 13.1 and an assumed, higher albedo of 0.20, which is a typical value for silicaceous asteroids, that are abundant in the inner main-belt.[3][lower-alpha 1] In general, estimates of an asteroid's size are commonly based on the body's brightness. For a given absolute magnitude, the lower the body's reflectivity (albedo), the larger its calculated diameter.

    The minor planet was named after Paul Daléra, a friend of Louis Boyer.[2]

    References

    1. 1 2 Collaborative Asteroid Lightcurve Link – using a transformed absolute magnitude. Explanation: a transformed absolute magnitude is used only in those cases where the adopted H value is based on a details line but the reported value in that line was not in the V band. When no color index is available, the default color indices V-R 0.45, B-V 0.80, and V-r' 0.23 are used to convert H_R and H_B to H_V. Summary figures and README.txt file at Collaborative Asteroid Lightcurve Link (CALL) for (1511) Dalera
    1. 1 2 3 4 5 6 "JPL Small-Body Database Browser: 1511 Dalera (1939 FB)" (2015-06-18 last obs.). Jet Propulsion Laboratory. Retrieved 27 April 2016.
    2. 1 2 Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (1511) Daléra. Springer Berlin Heidelberg. p. 120. ISBN 978-3-540-29925-7. Retrieved 6 December 2015.
    3. 1 2 3 4 5 6 7 "LCDB Data for (1511) Dalera". Asteroid Lightcurve Database (LCDB). Retrieved 6 December 2015.
    4. 1 2 "Absolute Magnitude (H)". NASA/JPL. Retrieved 6 December 2015.
    5. 1 2 Scardella, Maurizio; Franceschini, Francesco; Tomassini, Angelo (July 2015). "Rotational Period of 1511 Dalera". The Minor Planet Bulletin. 42 (3): 216. Bibcode:2015MPBu...42Q.216S. ISSN 1052-8091. Retrieved 6 December 2015.
    6. 1 2 Salvaggio, Fabio; Marchini, Alessandro; Franco, Lorenzo (July 2015). "Rotation Period Determination for 1511 Dalera and 2271 Kiso". The Minor Planet Bulletin. 42 (3): 226–227. Bibcode:2015MPBu...42..226S. ISSN 1052-8091. Retrieved 6 December 2015.
    7. 1 2 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:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 6 December 2015.
    8. ↑ "1511 Dalera (1939 FB)". Minor Planet Center. Retrieved 6 December 2015.

    External links


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