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Hayabusa (MUSES-C: Asteroid Sample-return Spacecraft) is a Japanese engineering spacecraft by the Institute of Space and Astronautical Science of Japan Aerospace Exploration Agency (ISAS/JAXA) aiming at sample return from S-type asteroid (25413) Itokawa (Fujiwara et al., 2006). Between September and November 2005, Hayabusa observed Itokawa by Asteroid Multiband Imaging CAmera (AMICA) and Near Infrared Spectrometer (NIRS). A filter wheel of AMICA has a wide bandpass filter and ECAS (Eight Color Asteroid Survey) narrowband filters: 380 (ul), 430 (b), 550 (v), 700 (w), 860 (x), 960 (p), and 1,010 nm (zs) (Nakamura et al., 2001; Saito et al., 2001). AMICA observed the whole surface of Itokawa with the solar phase angle around 10 degree with nominal resolution 70 cm from the Home Position (HP) at approximate distance 7 km. Observations from closer distances were also performed with resolution less than 1 cm during touchdown phases., 資料番号: AA0063505019

We have developed a spectrograph for asteroid's spectra. Option part for asteroidal spectroscopy was added to an optical spectrometer mounted on the NAYUTA telescope. To check asteroid spectrum, we observe asteroid 4 Vesta in the 0.52-0.98 micrometer spectral region at rotational phase. We succeeded in getting a right spectrum in the device to compare Vesta past spectra. Rotational spectra of Vesta are also investigated. Our result is consistent with past result (Binzel et al. 1997)., 資料番号: AA0063505048

High-quality visual-infrared color profiles have been determined for elliptical galaxies for the first time. Surface photometry in J and K is presented for 12 bright elliptical galaxies, and the results have been combined with CCD data in visual passbands. It is shown that the galaxies become bluer in V-K by an average of 0.16 mag/dex with increasing radius. There is a strong correlation between radial color gradients in U-V, B-V, and V-K for 11 of the galaxies. Models to interpret the color profiles are constructed which indicate that the stellar populations in elliptical galaxies can be explained by a single burst population with a contribution of a few percent of the light in V from blue stars. Metallicity is a possible candidate for the parameter causing radial color gradients.

International audience; The distribution of interstellar extinction has been mapped over the whole sky, using all available spectral and photometric data. The color excess distribution is modelled as a function of galactic latitude, longitude and distance within about 1 kpc from the sun. The model was used to predict the reddened Tycho and Johnson (B-V) colors, with the associated accuracy, from HD or MK spectral type and one magnitude (B or V), for stars without photoelectric photometry. This model is of special interest at intermediate and high galactic latitudes where color excesses cannot be obtained from early type stars.

High-quality visual-infrared color profiles have been determined for elliptical galaxies for the first time. Surface photometry in J and K is presented for 12 bright elliptical galaxies, and the results have been combined with CCD data in visual passbands. It is shown that the galaxies become bluer in V-K by an average of 0.16 mag/dex with increasing radius. There is a strong correlation between radial color gradients in U-V, B-V, and V-K for 11 of the galaxies. Models to interpret the color profiles are constructed which indicate that the stellar populations in elliptical galaxies can be explained by a single burst population with a contribution of a few percent of the light in V from blue stars. Metallicity is a possible candidate for the parameter causing radial color gradients.

Deep B and V frames have been obtained for Arp-Madore 1 (AM-1) using the Cerro Tololo 4 m telescope and prime focus CCD camera, confirming the nature of this object as a globular cluster. In particular, the resulting color-magnitude diagram shows a sharply defined red horizontal branch at apparent magnitude m(V) = 20.93 + or - 0.04. Adopting M(V)(HB) = 0.6 then yields a galactocentric distance of 118 kpc, an amount placing AM-1 as the most distant globular cluster yet identified which may still be associated with the Galaxy. From the color of the giant branch at the horizontal branch, Fe/H is estimated as -1.8 + or - 0.3, a value which lends support to previous arguments that the abundance gradient in the outer halo is weak. In stellar content AM-1 appears similar to the other low-luminosity members of the outer halo - the Palomar clusters and dwarf spheroidals.

Synthetic models are computed in order to study the evolution with time of integrated luminosities and colors for stellar systems spanning ranges of total mass and metal abundance similar to those characteristic of the Small and Large Magellanic Clouds (SMC and LMC) globular-like clusters. General aspects of this synthetic approach, results relative to the integral bolometric and U, B, V fluxes and colors, and indications on the reliability of photometric synthesis in giving informations on the stellar content of star clusters are discussed. A picture for the formation and evolution of the Cloud clusters is discussed on the basis of the comparison between theory and observations. In particular, an evaluation of the masses for a sample of MC clusters based on the models is given, a discussion of the problem of the gap in the integral color distributions is reported, and a possible solution on the basis of the synthetic models is suggested. 114 refs.