719 Albert

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719 Albert
Discovery[1]
Discovered by Johann Palisa
Discovery site Imperial Observatory, Vienna
Discovery date October 3, 1911
Designations
Named after Albert Salomon von Rothschild
Alternative names 1911 MT; 2000 JW8
Minor planet category Amor Amor
Mars-crosser
Orbital characteristics[2]
Epoch 2008-05-14 (JD 2454600.5)
Aphelion 4.080300074 ± 1.7224e-08 AU
Perihelion 1.17634643 ± 9.2337e-08 AU
Semi-major axis 2.628323253 ± 1.1095e-08 AU
Eccentricity .552434643 ± 3.4904e-08
Orbital period 4.26 ± 2.698e-08 a
Average orbital speed 16.87 km/s
Mean anomaly 205.2955438 ± 1.5165e-06°
Inclination 11.5551994 ± 6.5388e-06°
Longitude of ascending node 184.060354 ± 2.1126e-05°
Time of periastron 2455269.3318031 ± 6.0276e-06 JED
Argument of perihelion 155.779766 ± 2.5666e-05°
Physical characteristics
Dimensions 2.4 km[3]
Mass 1.4×1013 kg
Mean density 2.0? g/cm³
Equatorial surface gravity ~0.0007 m/s²
Escape velocity ~0.0013 km/s
Rotation period 5.802 h[4]
Albedo assumed 0.15[3] or 0.12[4]
Temperature ~171 K
Spectral type S[5]
Absolute magnitude (H) 15.8[6]

719 Albert is a Mars-crossing, Amor asteroid; it was the second one discovered after 433 Eros.

Discovery[edit]

Discovered in 1911 by Johann Palisa, the asteroid was named after one of the Imperial Observatory in Vienna's major benefactors, Albert Salomon von Rothschild, who had died some months before.[1] Due to inaccuracies in the asteroid's computed orbit it was subsequently lost and not recovered until 2000 by Jeffrey Larsen using data from the Spacewatch asteroid survey project.[1] When it was recovered in 2000, Albert was the last "lost asteroid" among those assigned numbers (69230 Hermes was not numbered until 2003). The second-to-last "lost" numbered asteroid, 878 Mildred, had been recovered in 1991.[1]

When it was rediscovered 719 Albert was mistakenly thought to be a new asteroid and was designated 2000 JW8.[7] Upon further investigation, however, it was noticed that its orbital plane matched up nicely with the last remaining "lost" asteroid and it was properly identified. Using the new observational data the period was determined to be about 4.28 years instead of the 4.1 years calculated in 1911; this was the primary reason the asteroid was lost.[1]

...asteroids were sometimes assigned numbers before accurate orbital elements had been determined, and so some numbered asteroids could not later be located. These objects were referred to as “lost” asteroids. The final lost numbered asteroid, (719) Albert, was recovered in 2000 after a lapse of 89 years. Many newly discovered asteroids still become “lost” ...

Encyclopædia Britannica [8]

Physical properties[edit]

Most of what is known about 719 Albert comes from observations taken after its rediscovery. In 2001 it passed near the Earth, allowing for a series of observations at differing phase angles. During this pass its rotational period was calculated at 5.802 hours and a measured absolute magnitude of 15.43 together with an assumed albedo of 0.12 gave a diameter of 2.8 km.[4] Another group led by R. P. Binzel measured an absolute magnitude of 15.8; they however used an assumed albedo of 0.15 leading to a calculated diameter of 2.4 km.[3] Other observations carried out in October 2001 at the 5 meter Hale Telescope by Binzel et al. classified it as an S-type asteroid.[5]

References[edit]

  1. ^ a b c d e Cowen, Ron (2000-05-20). "Astronomers Rediscover Long-Lost Asteroid" 157 (21). Science News. 
  2. ^ 719 Albert at the JPL Small-Body Database
  3. ^ a b c Binzel, R. P.; et al. (2002). "Physical Properties of Near-Earth Objects" (PDF). Asteroids III (University of Arizona Press): 255–271. ISBN 0-8165-2281-2. 
  4. ^ a b c Krugly, Yu. N.; Belskaya, I. N.; Chiorny, V. G.; Shevchenko, V. G.; Gaftonyuk, N. M. (November 2002). "CCD Photometry of Near-Earth Asteroids in 2001". Proceedings of Asteroids, Comets, Meteors 500: 903–906. Bibcode:2002ESASP.500..903K. ISBN 92-9092-810-7. 
  5. ^ a b Binzel, R. P.; et al. (August 2004). "Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes" (PDF). Icarus 170 (2): 259–294. Bibcode:2004Icar..170..259B. doi:10.1016/j.icarus.2004.04.004. 
  6. ^ Mpec 2000-J37. 2000-05-09. 
  7. ^ IAU Circular: IAUC 7420. 2000-05-09. 
  8. ^ lost asteroid. (2009). In Encyclopædia Britannica. Retrieved February 27, 2009, from Encyclopædia Britannica Online: http://www.britannica.com/EBchecked/topic/348392/lost-asteroid

External links[edit]