719 Albert
Encyclopedia
719 Albert is a Mars-crossing
, Amor asteroid
; it was the second one discovered after 433 Eros
.
, 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. 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 . 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.
s. 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. 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. Other observations carried out in October 2001 at the 5 meter Hale Telescope
by Binzel et al. classified it as an S-type asteroid
.
Mars-crosser asteroid
A Mars-crosser is an asteroid whose orbit crosses that of Mars. The known numbered Mars-crossers are listed here. They include the two numbered Mars trojans 5261 Eureka and ....
, Amor asteroid
Amor asteroid
The Amor asteroids are a group of near-Earth asteroids named after the asteroid 1221 Amor. They approach the orbit of the Earth from beyond, but do not cross it. Most Amors do cross the orbit of Mars...
; it was the second one discovered after 433 Eros
433 Eros
433 Eros is a near-Earth asteroid discovered in 1898, and the first asteroid to be orbited by a probe . It is an S-type asteroid approximately 34.4×11.2×11.2 km in size, the second-largest NEA after 1036 Ganymed, and belongs to the Amor group.Eros is a Mars-crosser asteroid, the first known...
.
Discovery
Discovered in 1911 by Johann PalisaJohann Palisa
Johann Palisa was an Austrian astronomer, born in Opava in Austrian Silesia .He was a prolific discoverer of asteroids, discovering 122 in all, from 136 Austria in 1874 to 1073 Gellivara in 1923...
, the asteroid was named after one of the Imperial Observatory in Vienna's major benefactors, Albert Salomon von Rothschild
Albert Salomon von Rothschild
Albert Salomon von Rothschild was a banker in Austria-Hungary and a member of the Rothschild banking family of Austria. Businesses that he owned included Creditanstalt and the Northern Railway.-Personal life:...
, 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
Spacewatch
Spacewatch is a project at the University of Arizona led by Robert S. McMillan that specializes in the study of minor planets, including various types of asteroids and comets...
asteroid survey project. When it was recovered in 2000, Albert was the last "lost asteroid" among those assigned numbers (69230 Hermes
69230 Hermes
-External links:* * *...
was not numbered until 2003). The second last "lost" numbered asteroid, 878 Mildred
878 Mildred
878 Mildred is a minor planet in the main belt orbiting the Sun. It is the lowest numbered, and thus the namesake, of the Mildred family of asteroids, a subgroup of the Nysa family...
, had been recovered in 1991.
When it was rediscovered 719 Albert was mistakenly thought to be a new asteroid and was designated . 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 anglePhase angle (astronomy)
Phase angle in astronomical observations is the angle between the light incident onto an observed object and the light reflected from the object...
s. 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. Another group led by R. P. Binzel
Richard P. Binzel
Richard "Rick" P. Binzel is a Professor of Planetary Sciences at the Massachusetts Institute of Technology. He is the inventor of the Torino Scale, a method for categorizing the impact hazard associated with near-Earth objects such as asteroids and comets.Binzel was awarded the H. C. Urey Prize...
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. Other observations carried out in October 2001 at the 5 meter Hale Telescope
Hale telescope
The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in California, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation, he orchestrated the planning, design, and construction of the observatory, but did not live to see its commissioning...
by Binzel et al. classified it as an S-type asteroid
S-type asteroid
S-type asteroids are of a stony composition, hence the name. Approximately 17% of asteroids are of this type, making it the second most common after the C-type.-Characteristics:...
.