719 Albert

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0
name = 719 Albert
discoverer = Johann Palisa
discovered = October 3, 1911
discovery_site = Imperial Observatory, Vienna
discovery_ref =
alt_names = 1911 MT; mp|2000 JW|8
mp_category = Amor, Mars-crosser
epoch = 2008-05-14 (JD 2454600.5)
aphelion = 4.080300074 ± 1.7224e-08 AU
semimajor = 2.628323253 ± 1.1095e-08 AU
perihelion = 1.17634643 ± 9.2337e-08 AU
eccentricity = .552434643 ± 3.4904e-08
period = 4.26 ± 2.698e-08 a
mean_anomaly = 205.2955438 ± 1.5165e-06°
inclination = 11.5551994 ± 6.5388e-06°
asc_node = 184.060354 ± 2.1126e-05°
arg_peri = 155.779766 ± 2.5666e-05°
time_periastron = 2455269.3318031 ± 6.0276e-06 JED
orbit_ref = JPL Small Body]
avg_speed = 16.87 km/s
dimensions = 2.4 km
mass = 1.4×10¹³ kg
density = 2.0? g/cm³
surface_grav = ~0.0007 m/s²
escape_velocity = ~0.0013 km/s
rotation = 5.802 h
spectral_type = S
abs_magnitude = 15.8 [Cite journal | title = Mpec 2000-J37 | date = 2000-05-09 | url = http://cfa-www.harvard.edu/iau/mpec/K00/K00J37.html]
albedo = assumed 0.15 or 0.12
single_temperature = ~171 K

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

Discovery

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. 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.Cite news | title = Astronomers Rediscover Long-Lost Asteroid | first = Ron | last = Cowen | date = 2000-05-20 | publisher = Science News | volume = 157 | issue = 21 | url = http://sciencenewsmagazine.org/view/generic/id/489/title/Astronomers_rediscover_long-lost_asteroid] 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 last "lost" numbered asteroid, 878 Mildred, had been recovered in 1991.

When it was rediscovered 719 Albert was mistakenly thought to be a new asteroid and was designated mp|2000 JW|8. [Cite journal | title = IAU Circular: IAUC 7420 | date = 2000-05-09 | url = http://cfa-www.harvard.edu/iauc/07400/07420.html] 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.

Physical properties

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.Cite journal | title = CCD Photometry of Near-Earth Asteroids in 2001 | last = Krugly | first = Yu. N. | coauthors = Belskaya, I. N.; Chiorny, V. G.; Shevchenko, V. G.; Gaftonyuk, N. M. | date = November 2002 | journal = Proceedings of Asteroids, Comets, Meteors | id = ISBN 92-9092-810-7 | pages = 903–906 | url = http://adsabs.harvard.edu/abs/2002ESASP.500..903K] 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.Cite journal | title = Physical Properties of Near-Earth Objects | last = Binzel | first = R. P. | coauthors = et al. | date = 2002 | publisher = University of Arizona Press | journal = Asteroids III | id = ISBN 0816522812 | pages = 255–271 | url = http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3048.pdf] Other observations carried out in October 2001 at the 5 meter Hale Telescope by Binzel et al. classified it as an S-type asteroid.Cite journal | title = Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes | last = Binzel | first = R. P. | coauthors = et al. | date = August 2004 | journal = Icarus | volume = 170 | issue = 2 | pages = 259–294 | url = http://www.mtholyoke.edu/courses/tburbine/tomburbine/binzel.2004.pdf | doi = 10.1016/j.icarus.2004.04.004]

References

External links

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* [http://earn.dlr.de/nea/000719.htm EARN Database: 719 Albert]