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This paper shows the first result of a Geminid meteor spectrum in the visible–ultraviolet region. Wavelengths between 300–600 nm were observed on the meteor which appeared at UT on 2004 December 14, and strong emissions of neutral atoms such as mainly MgI, FeI, CaI and NaI were identified. The abundances of metallic atoms and their excitation temperature were obtained on the assumption that a Boltzmann distribution for the population of each energy level. The results suggest the possibility that the abundances of Geminid meteors are slightly different from solar abundances. Na/Mg = 0.0036 ± 0.0005, which is much lower than other meteor showers. On the other hand, the Ni/Mg ratio is 0.078 ± 0.012, which is larger than solar abundance, and that of meteors of other showers. Extreme Na depletion, and moreover, excess Ni are derived for a Geminid meteor. The excitation temperature value, 4640.6 ± 1.5 K is consistent with their moderate velocity.

Accepted: 2004-12-28, 資料番号: SA1003350000

This paper shows the first observational result of a spectrum of a June Bootid meteor obtained by the High-Definition TV observational system. The very faint spectrum appeared at 15 h 59 m 29.693 s on 2004 June 23 UT, which was about 5th mag- nitude. Wavelengths between 360−620 nm were observed, and the strong emissions of neutral atoms as MgI, FeI and NaI were identified. Emissions of single ionized atoms were not observed. The abundances of metallic atoms, their excitation tempera- ture were obtained under the Local Thermal Equilibrium (LTE) conditions. The results, Fe/Mg = 0.15 and Na/Mg = 0.00027 suggest the possibility that the abundances of June Bootid meteor are extremely different from the solar system abundances. The excitation temperature value, 3867 ± 13 K is low in agreement with their slow moving velocity.

We present spectropolarimetry of the Type Ic supernova SN 2002ap and give a preliminary analysis: the data were taken at two epochs, close to and one month later than the visual maximum (2002 February 8). In addition we present June 9 spectropolarimetry without analysis. The data show the development of linear polarization. Distinct polarization profiles were seen only in the O I \lambda 7773 multiplet/Ca II IR triplet absorption trough at maximum light and in the Ca II IR triplet absorption trough a month later, with the latter showing a peak polarization as high as ~2 %. The intrinsic polarization shows three clear position angles: 80 degs for the February continuum, 120 degs for the February line feature, and 150 degs for the March data. We conclude that there are multiple asymmetric components in the ejecta. We suggest that the supernova has a bulk asymmetry with an axial ratio projected on the sky that is different from 1 by of order 10 %. Furthermore, we suggest very speculatively that a high velocity ejecta component moving faster than ~0.115c (e.g., a jet) contributes to polarization in the February epoch.

JEM-EUSO is a space science mission to explore the extreme energies and physics of the Universe. Its instrument will watch the darkside of the earth and will detect UV photons emitted from the extensive air shower caused by an ultra-high energy cosmic ray (UHECR above 1018 eV), or an extremely high energy cosmic ray (EHECR) particle (e.g. above about 1020 eV). Such a high-rigidity particle as the latter arrives almost in a straight line from its origin through the magnetic fields of our Milky Way Galaxy and is expected to allow us to trace the source location by its arrival direction. This can open the door to new astronomy with charged particles. In its 5 years of operation including the tilted mode, Extreme Universe Space Observatory an Japanese Experiment Module (JEM-EUSO) will detect at least 1000 events with E > 7 × 1019 eV with the Greisen–Zatsepin–Ku’zmin (GZK) suppression spectrum. It can determine the energy spectrum and source locations of GZK to super-GZK regions with a statistical accuracy of several percent. JEM-EUSO is planned to be deployed by H2 transfer vehicle (HTV) and will be attached to the Japanese Experiment Module/Exposure Facility (JEM/EF) of International Space Station. JAXA has selected JEM-EUSO as one of the mission candidates of the second phase utilization of JEM/EF for launch in the early-to-mid 2010 s.

The design of a mid-infrared high dispersion spectrograph with a resolution of 200,000 at 10μm employing germanium immersion grating elements is required for the ‘SUBARU’ large space telescope. The authors applied an ultraprecision micro-grinding technique using fine-diamond grinding tools whose edges have been sharpened by electrical and mechanical processes to fabricate the element, and successfully obtained the required element with a sharp and smooth V-faced grating structure using germanium. The successful fabrication of this element is expected to contribute to the production of a compact and efficient high dispersion spectrograph in the development of the most advanced image analyzer.

We proposed an application of the refractive polarizing Fourier Transform Spectrometer (r-FTS) to millimeter submillimeter wave multiband polarimetry. In this paper, the results of optical experiments in millimeter wavebands, aiming to verify the performance, will be reported.

We propose an application of the refractive polarizing Fourier Transform Spectrometer (r-FTS) to broadband polarimetry. In this paper, fundamentals of instrument and the method to realize it are described.

This paper presents university-based design and development of a micro-satellite for the observation of a meteor shower from low Earth orbit. The satellite will be launched as a piggy-back payload of a commercial rocket launcher, before the 2002 Leonid meteor maximum in which tens of thousands of meteors are expected. The goal of the mission is to make observations of the meteor outburst from beyond the atmosphere, counting the meteors over a large part of the night sky and obtaining visible and ultraviolet spectra of the meteors.

We have been studied the advanced Thomson scattering diagnostics from viewpoints of new concepts, laser technology and spectrum analysis. This paper summarizes results of development on technologies for advanced Thomson scattering diagnostics.