A5083199463- Astro and Planetary Science
- Planetary Science and Exploration
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Isotope Analysis in Ecology
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Thermography and Photoacoustic Techniques
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Infrared Target Detection Methodologies
- Space Satellite Systems and Control
- Pulsars and Gravitational Waves Research
- Laser-induced spectroscopy and plasma
- Calibration and Measurement Techniques
The University of Tokyo
2021-2024
Observatoire de la Côte d’Azur
2024
Université Côte d'Azur
2024
Centre National de la Recherche Scientifique
2024
Institute of Astronomy
2020
In this Letter we report a discovery of prominent flash peculiar overluminous Type Ia supernova, SN 2020hvf, in about 5 hours the supernova explosion by first wide-field mosaic CMOS sensor imager, Tomo-e Gozen Camera. The fast evolution early was captured intensive intranight observations via high-cadence survey. Numerical simulations show that such and emission is most likely generated from an interaction between $0.01~M_{\odot}$ circumstellar material (CSM) extending to distance...
We report on the first polarimetric study of (3200) Phaethon, target JAXA's DESTINY$^+$ mission, in negative branch to ensure its anhydrous nature and derive an accurate geometric albedo. conducted observations at low phase angles (Sun-target-observer angle, alpha = 8.8-32.4 deg) from 2021 October 2022 January found that Phaethon has a minimum polarization degree $P_{min}$ -1.3 +- 0.1 %, slope h 0.22 0.02 % deg$^{-1}$, inversion angle alpha$_0$ 19.9 0.3 deg. The derived albedo is $p_V$ 0.11...
Abstract Asteroid systems such as binaries and pairs are indicative of the physical properties dynamical histories small solar system bodies. Although numerous observational theoretical studies have been carried out, formation mechanism asteroid is still unclear, especially for near-Earth (NEA) pairs. We conducted a series optical photometric polarimetric observations NEA 2010 XC 15 in 2022 December to investigate its surface properties. The rotation period possibly few several dozen hours...
We report the results of video observations tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on Kiso 105 cm Schmidt telescope. A rotational period a asteroid reflects its dynamical history and physical properties since smaller are sensitive to YORP effect. carried out 60 NEOs at 2 fps from 2018 2021 successfully derived periods axial ratios 32 including 13 fast rotators s. The fastest rotator found during our survey is 2020 HS7 2.99 statistically confirmed that...
Abstract Accurate estimations of the brightness (3200) Phaethon up to lower phase angles are essential for planning on-board camera DESTINY+ mission. We carried out intensive observations in optical wavelength (g, r, and i) with TriCCS on Seimei 3.8 m telescope 2021 October November. derived absolute magnitude HV slope parameter G as = 14.23 ± 0.02 0.040 0.008 from multiple photometric including down ∼9° H–G model. Using value geometric albedo previous polarimetric studies, we estimated that...
IntroductionStudying near-Earth asteroids (NEAs) is fundamental to understanding material transportation in our solar system and mitigating the hazard of asteroid impacts. Most NEAs have their origins main belt between orbits Mars Jupiter. Asteroidal fragments are thought be generated from collisional events gradually drifted by Yarkovsky effect, which a thermal force caused radiation Sun. During orbital evolution, rotation states object changed YORP arises asymmetricity scattered sunlight...
Context. Characterizing mission-accessible asteroids using telescopic observations is fundamental for target-selection and planning spacecraft missions. Near-Earth on Earth-like orbits are of particular importance applications such as asteroid mining. Aims. 2001 QJ142 a tiny (D $\leq$ 100 m) near-Earth an orbit with semimajor axis 1.06 au, orbital eccentricity 0.09, inclination 3.10$^{\circ}$. We aim to characterize ground-based future missions in mind. Methods. performed visible multicolor...
Abstract Studying small near-Earth asteroids is important in order to understand their dynamical histories and origins as well mitigate the damage caused by asteroid impacts on Earth. We report results of multicolor photometry tiny 2015 RN 35 using 3.8 m Seimei telescope Japan TRAPPIST-South Chile over 17 nights 2022 December 2023 January. observed across a wide range phase angles from 2° 30° g , r i z bands Pan-STARRS system. These lightcurves show that nonprincipal axis spin state with two...
We report on simultaneous optical and X-ray observations of the dwarf nova SS Cyg with Tomo-e Gozen/1.05 m Kiso Schmidt Neutron star Interior Composition ExploreR (it NICER) / International Space Station (ISS). A total four were carried out in quiescent state highly correlated light variations between two wavelengths detected. have extracted local brightness peaks curves a binning interval 1 sec, called `shots', evaluated time lags by using cross-correlation function. Some shots exhibit...
Asteroid systems such as binaries and pairs are indicative of physical properties dynamical histories the Small Solar System Bodies. Although numerous observational theoretical studies have been carried out, formation mechanism asteroid is still unclear, especially for near-Earth (NEA) pairs. We conducted a series optical photometric polarimetric observations small NEA 2010 XC$_{15}$ in 2022 December to investigate its surface properties. The rotation period possibly few several dozen hours...
Studying small near-Earth asteroids is important to understand their dynamical histories and origins as well mitigate the damage of asteroid impact Earth. We report results multicolor photometry tiny 2015 RN$_{35}$ using 3.8 m Seimei telescope in Japan TRAPPIST-South Chile over 17 nights 2022 December 2023 January. observed across a wide range phase angles from 2$^{\circ}$ 30$^{\circ}$ $g$, $r$, $i$, $z$ bands Pan-STARRS system. These lightcurves show that non-principal axis spin state with...
Automatic survey observations require a high-resolution cloud monitor providing areas of clear sky to telescope system. A wide-field thermal camera is powerful tool for monitoring distribution regardless scattered lights from the Moon and nearby cities. We developed compact mid-infrared all-sky using waterproof module with Ge lens an 80 x 80-pixel Si-bolometer array wavelengths 8 12 microns magnifying mirror diameter 100 mm. The magnifier has rotationally symmetrical shape round-shaped...
Accurate estimation of brightness (3200) Phaethon up to lower phase angles are essential for planning the on-board camera DESTINY$^{+}$ mission. We have carried out intensive observations in optical wavelength ($g$, $r$, and $i$) with TriCCS on Seimei 3.8 m telescope October November, 2021. derived absolute magnitude $H_\mathrm{V}$ slope parameter $G$ as $H_\mathrm{V}=14.23\pm0.02$ $G=0.040\pm0.008$ from multiple photometric including down $\sim$9$^{\circ}$ $H$-$G$ model. Using value...