講演者: 阿部　新助 (神戸大学 大学院自然科学研究科 COE研究員)   
  題名: Density estimation of asteroid Itokawa and Spectroscopy of Meteoroids
  日時: 2006年04月07日（金）12:15-13:00
  場所: 自然科学3号館6階セミナー室 609号室




Activities carried out by Shinsuke Abe were primarily focused on



(1) Hayabusa, LIght Detection And Ranging instrument (LIDAR, P.I.;
Mukai-sann) aboard the spacecraft provided information on the surface
topography of asteroid 25143 Itokawa and its mass. The mass of Itokawa
was estimated from LIDAR ranges measured on November 11, 2005 (UT) as
3.58+-0.18 x E+10 kg. I will present our estimated bulk density and
porosity for the asteroid Itokawa and discuss about the interior
structure such as a rubble pile.



(2) Spectroscopy related to meteor and meteor train's spectrum.
 The first work entitled 'Detection of the N2+ First Negative
System in a Bright Leonid Fireball' was publish in the Astrophysical
Journal(2005). A reentry of Stardust mission which is a cometary
sample return mission, was a good opportunities for confirming the
discovered molecules and I participated in NASA's airborne mission to
obtain spectra of this reentry. The second work entitled 'Video and
Photographic Spectroscopy of 1998 and 2001 Leonid Persistent Trains
from 300 to 930 nm' was published to Earth, Moon and
Planets(2005). Bright fireballs sometimes leave a long-lasting glow
that is called a persistent train which lasts long after the
disappearance of its parent meteor. However, the knowledge of physical
process of trains is still far from satisfactory.