El destino del asteroide Albert.

ORELLANA, R. B.; MELITA, M. D.; BRUNINI, A.

Rosario

Congreso; Reunión Nº 43 de la Asociación Argentina de Astronomía; 1999

IFIR

Albert is the only numbered asteroid that remains lost at present. This object has been discovered while it was making a close approach to the Earth by Johann Palisa in teh Imperial Observatory of Vienna. According to the satandard procedure of the time, a number was assigned to it shortly after a preliminar orbit has been obtained and it was named after a great benefactor of Imperial Observatory, Baron Albert von Rothschild. in this work we analize why this body could not be recovered in its subsequent approaches to the Earth. Basicaly the cause of the loss can be summarized as follows. given the high absolute magnitude of the object it can only be observed when it is close to the Earth. But naturaly, at the close approaches, the uncertanty in the position in the celestial sphere is the greatest due to a parallax effect. We have estimated the uncertanty in R.A. and declination by the non-linear propagation of the initial observational uncertanty. We have determined that, when the aparent magnitude was low enough to observe the object with the instruments available at the time, the uncertainty region exceeded noticeably the region where it was searched. Regarding its possible recovery at present, the uncertainty in its position practicaly covers the whole sky. Nevertheless, the plane of the orbit is bounded in a narrow strip for a considerable length of time, which makes its recovery posible in old plates. The causes of the loss of Albert (719) are common to all NEO´s, which is distintive about it is thet it was numbered after just a few observations, while at present the standard procedure requires that the orbit should be very well established before a denomination is given. Given the almost imposibility of its systematic recovery, in the future Albert (719) might be the first asteroid whose denomination is reassigned to another object.