Apollo asteroid 2008 HW1

M.P.E.C. 2008-H35, issued on 2008 Apr. 28, 18:44 UT, announces the discovery of 2008 HW1, an Apollo asteroid in a very comet-like orbit (Tj nearly 2.4; Jupiter family comets have Tisserand parameter TJ between 2 and 3). It was picked-up by the staff of Lincoln Laboratory ETS through a 1.0-m f/2.15 reflector + CCD, on 2008 April 25.35091. After its posting on the NEO Confirmation Page, further follow-up was secured by a number of observers. 

According the preliminary orbital elements published by the Minor Planet Center, 2008_HW1 moves along a very elongated orbit (e~0.96), that takes a little more than 4 years to be completed; at aphelion it approaches the orbit of Jupiter (Q~ 5 AU), while at perihelion (that will be reached in middle of next June) is passes only 0.1 AU - or nearly 15 Million Km - from the Sun. This is a rock whose diameter is supposed to range from nearly 600-m to 2-Km (depending on its surface reflectivity).

We performed some follow-up on 2008, April 28.0, from the Remanzacco Observatory (MPC #473):

In spite of its very comet-like orbit, in our stackings (total exposure time of 30 minutes) this object appears perfectly stellar, with no hints of any detectable coma or tail within our seeing limit.

by L. Donato, M. Gonano, V. Gonano, E. Guido, V. Santini and G. Sostero