[Show abstract][Hide abstract] ABSTRACT: We observed the lightcurves of 13 V-type asteroids [(1933) Tinchen, (2011) Veteraniya, (2508) Alupka, (3657) Ermolova, (3900) Knezevic,
(4005) Dyagilev, (4383) Suruga, (4434) Nikulin, (4796) Lewis, (6331) 1992 FZ1, (8645) 1998 TN, (10285) Renemichelsen, and (10320) Reiland]. Using these observations we determined the rotational rates
of the asteroids, with the exception of Nikulin and Renemichelsen. The distribution of rotational rates of 59 V-type asteroids
in the inner main belt, including 29 members of the Vesta family, which are regarded as being ejecta from the asteroid (4) Vesta,
is inconsistent with the best-fit Maxwellian distribution. This inconsistency may be due to the effect of thermal radiation
Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) torques, which implies that the collision event that formed V-type asteroids
is sub-billion to several billion years in age.
Publications- Astronomical Society of Japan 11/2013; 66(3). DOI:10.1093/pasj/psu040 · 2.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lightcurves of 20 V-type asteroids and 13 asteroids are by-productions
for V-type asteroid observations have been obtained. We have determined
rotation periods of 18 V-type asteroids and 11 non V-type asteroids.
[Show abstract][Hide abstract] ABSTRACT: To examine the distribution of rotational rates for chips of asteroid 4
Vesta, lightcurve observation of seven V-type asteroids (2511 Patterson, 2640
Hallstorm, 2653 Principia, 2795 Lapage, 3307 Athabasca, 4147 Lennon, and 4977
Rauthgundis) were performed from fall 2003 to spring 2004. Distribution of spin
rates of V-type main-belt asteroids from the past and our observations have
three peaks. This result implies that age of catastrophic impact making Vesta
family may be not as young as Karin and Iannini families but as old as Eos and
[Show abstract][Hide abstract] ABSTRACT: Cometary dust trails were first observed by IRAS; they are widely known to be the origins of meteoric showers. A new window has been opened for the study of dust trails, using ground-based observations. We succeeded in obtaining direct images of the 22P/Kopff dust trail with the Kiso 1.05-m Schmidt telescope. Following this initial success, we have continued to perform a dust trail survey at Kiso. As a result of this survey, we have detected dust trails along the orbit of six periodic comets, between February 2002 and March 2004. The optical depth of these dust trails are 10−9 to 10−8, which is consistent with IRAS measurements. In this paper, we describe the observations and data reduction procedures, and report the brief result obtained between February 2002 and March 2004.
Advances in Space Research 03/2009; 43(5-43):875-879. DOI:10.1016/j.asr.2008.07.010 · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We have observed 23 NEAs during 2003-2005, using the 1.05-m Kiso Schmidt telescope and the Lulin 1-m telescope. As the taxonomic types of 238 candidates are unknown, we performed the BVRI photometry. I present the results of multicolor photometry.
[Show abstract][Hide abstract] ABSTRACT: We report the results of multi-band photometry and lightcurve observation of the candidates of next generation asteroidal mission targets using Kiso observatory s 1-m telescope and Lulin observatory s 1-m Telescope since September 2003 Japan Aerospace Exploration Agency JAXA Institute of Space and Astronautical Science ISAS has been planning the next generation minor body exploration in succession to HAYABUSA MUSES-C mission HAYABUSA a Japanese engineering demonstration spacecraft launched on 9 May 2003 was designed to acquire samples from the surface of asteroid 25143 Itokawa 1998 SF36 and return them to earth The spacecraft arrived at distance of about 20 km from the asteroid on 12 September 2005 and successfully carried out the scientific observations The purpose of the present study is to obtain the taxonomic properties and rotational status of the candidate targets for the next mission For the selection of mission target it must be needed these information These candidate objects are considered nearly Earth-clossing asteroids which are dynamically accessible objects by spacecraft Although spectroscopy provides more detailed spectra of asteroidal surfaces we had performed the BVRI multi-band photometry because these objects commonly would have faint brightness typical aparent magnitude is 18 mag due to these sizes We determined the taxonomic type and rotational period of 11 unknown objects and 3 known objects Fortunately we found that 65803 Didymos one of the observed objects would be binary asteroid which consists of double
[Show abstract][Hide abstract] ABSTRACT: The asteroid of 25143 Itokawa is a target of the Japanese sample return mission, HAYABUSA. The optical observation of Itokawa had performed from March 2001 until October 2004. We report its absolute magnitude, slope parameter, and rotational period.
[Show abstract][Hide abstract] ABSTRACT: Cometary dust trails were discovered by the Infrared Astronomical
Satellite (IRAS). Recent visible detection by Kiso 105cm Schmidt opened
the new possibility to study the dust trails at any time. Dust trails
consist of large (mm to cm), dark particles, and they are the principal
mass loss mechanism for the comets with which they were associated.
Different from the 'dust tail' grains blown outward in short time scale
due to the comet's gas outflow and solar radiation pressure, the orbits
of dust trails are very similar to that of their parent comets and
gradually drift away toward the trailing direction. They have given us
the unique means of probing the relationship between the zodiacal cloud
complex and comets. The existence of 81P/Wild 2 dust trail discovered by
Kiso showed the importance of comet mission. We have performed the
cometary dust trail survey by Kiso 105cm Schmidt telescope. With the
flexible and quick follow-up framework, as well as the advantage of the
wide field view of 50'x50' and bright optics of F3.1, we try to detect
faint and extended dust trails at the vicinity of short period comet.
Since most of short period comets are located near the ecliptic plan, it
is not easy to identify trail to tail by a snap shot. If some candidates
were found, they were monitored for a several months. As a result, we
detect four new trails. In this paper, we report the characteristics of
these four trails. In addition, we obtained a sequence of dust trail
images of ROSETTA mission target, 67P/Churyumov-Gerasimenko, whose trail
was discovered by IRAS, during the apparition of 2002. Based on these
images, we discuss the impact probability to the spacecraft.