activity
19992026
most citedThermo-physical properties of 162173 (1999 JU3), a potential flyby and rendezvous target for interplanetary missions

93 citations · 355 across the 22 of their papers we have counts for

collaborators

22 papers

astro-ph.IM2026

DebrisWatch II: Digging deeper for geosynchronous debris

James A. Blake, Benjamin F. Cooke, Cristina Paragini +27

The geosynchronous (GSO) debris environment is continually evolving. Regular monitoring of the region is consequently of great importance, though the trade-off between coverage and…

astro-ph.EP2026

An optical transient candidate of 2-second duration captured by wide-field video observations

Noriaki Arima, Mamoru Doi, Shigeyuki Sako +14

Recent time-domain surveys have revealed rapid transients that evolve on timescales of days, expanding the transient population into the short-duration regime. The tr…

astro-ph.HE2024

Optical Variability of Blazars in the Tomo-e Gozen Northern Sky Transient Survey

TianFang Zhang, Mamoru Doi, Mitsuru Kokubo +14

We studied the optical variability of 241 BL Lacs and 83 flat-spectrum radio quasars (FSRQ) from the 4LAC catalog using data from the Tomo-e Gozen Northern Sky Transient Survey, wi…

astro-ph.HE2024

Intermediate-luminosity Type IIP SN 2021gmj: a low-energy explosion with signatures of circumstellar material

Yuta Murai, Masaomi Tanaka, Miho Kawabata +28

We present photometric, spectroscopic and polarimetric observations of the intermediate-luminosity Type IIP supernova (SN) 2021gmj from 1 to 386 days after the explosion. The peak…

astro-ph.HE2023

A search for extragalactic fast optical transients in the Tomo-e Gozen high-cadence survey

Kakeru Oshikiri, Masaomi Tanaka, Nozomu Tominaga +15

The population of optical transients evolving within a time-scale of a few hours or a day (so-called fast optical transients, FOTs) has recently been debated extensively. In partic…

astro-ph.EP2022★ 13 cited

Video Observations of Tiny Near-Earth Objects with Tomo-e Gozen

Jin Beniyama, Shigeyuki Sako, Ryou Ohsawa +20

We report the results of video observations of tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on the Kiso 105 cm Schmidt telescope. A rotational period…

astro-ph.SR2022★ 29 cited

Fast optical flares from M dwarfs detected by a one-second-cadence survey with Tomo-e Gozen

Masataka Aizawa, Kojiro Kawana, Kazumi Kashiyama +18

We report a one-second-cadence wide-field survey for M-dwarf flares using the Tomo-e Gozen camera mounted on the Kiso Schmidt telescope. We detect 22 flares from M3-M5 dwarfs with…

astro-ph.HE2022★ 15 cited

Deep simultaneous limits on optical emission from FRB 20190520B by 24.4 fps observations with Tomo-e Gozen

Yuu Niino, Mamoru Doi, Shigeyuki Sako +16

We conduct 24.4~fps optical observations of repeating Fast Radio Burst (FRB) 20190520B using Tomo-e Gozen, a high-speed CMOS camera mounted on the Kiso 105-cm Schmidt telescope, si…

astro-ph.HE2021★ 50 cited

Discovery of the Fastest Early Optical Emission from Overluminous SN Ia 2020hvf: A Thermonuclear Explosion within a Dense Circumstellar Environment

Ji-an Jiang, Keiichi Maeda, Miho Kawabata +28

In this Letter we report a discovery of a prominent flash of a peculiar overluminous Type Ia supernova, SN 2020hvf, in about 5 hours of the supernova explosion by the first wide-fi…

astro-ph.EP2020★ 6 cited

Relationship between Radar Cross Section and Optical Magnitude based on Radar and Optical Simultaneous Observations of Faint Meteors

Ryou Ohsawa, Akira Hirota, Kohei Morita +40

Radar and optical simultaneous observations of meteors are important to understand the size distribution of the interplanetary dust. However, faint meteors detected by high power l…

astro-ph.IM2019★ 12 cited

An optical search for transients lasting a few seconds

Michael W. Richmond, Masaomi Tanaka, Tomoki Morokuma +37

Using a prototype of the Tomo-e Gozen wide-field CMOS mosaic camera, we acquire wide-field optical images at a cadence of 2 Hz and search them for transient sources of duration 1.5…

astro-ph.EP2019★ 15 cited

New constraint on the atmosphere of (50000) Quaoar from a stellar occultation

Ko Arimatsu, Ryou Ohsawa, George L. Hashimoto +35

We report observations of a stellar occultation by the classical Kuiper belt object (50000) Quaoar occurred on 28 June 2019. A single-chord high-cadence (2 Hz) photometry dataset w…

astro-ph.EP2019★ 3 cited

Shape and Rotational Motion Models for Tumbling and Monolithic Asteroid 2012 :High Time Resolution Lightcurve with the Tomo-e Gozen Camera

Seitaro Urakawa, Ryou Ohsawa, Shigeyuki Sako +13

We present visible and near-infrared observations of a near-Earth object (NEO), 2012 . The NEO 2012 approached close to the Earth at a distance of ab…

astro-ph.EP2018★ 18 cited

Physical properties of near-Earth asteroids with a low delta-: Survey of target candidates for the Hayabusa2 mission

Sunao Hasegawa, Daisuke Kuroda, Kohei Kitazato +40

Sample return from the near-Earth asteroid known as 25143 Itokawa was conducted as part of the Hayabusa mission, with a large number of scientific findings being derived from the r…

astro-ph.EP2018★ 3 cited

Luminosity Function of Faint Sporadic Meteors measured with a Wide-Field CMOS mosaic camera Tomo-e PM

Ryou Ohsawa, Shigeyuki Sako, Yuki Sarugaku +34

Imaging observations of faint meteors were carried out on April 11 and 14, 2016 with a wide-field CMOS mosaic camera, Tomo-e PM, mounted on the 105-cm Schmidt telescope at Kiso Obs…

astro-ph.EP2017★ 32 cited

Against the biases in spins and shapes of asteroids

A. Marciniak, F. Pilcher, D. Oszkiewicz +21

Physical studies of asteroids depend on an availability of lightcurve data. Targets that are easy to observe and analyse naturally have more data available, so their synodic period…

astro-ph.HE2015★ 10 cited

Multi-wavelength observations of the black widow pulsar 2FGL J2339.6-0532 with OISTER and Suzaku

Yoichi Yatsu, Jun Kataoka, Yosuke Takahashi +41

Multi-wavelength observations of the black-widow binary system 2FGL J2339.6-0532 are reported. The Fermi gamma-ray source 2FGL J2339.6-0532 was recently categorized as a black wido…

astro-ph.HE2013★ 17 cited

Dense optical and near-infrared monitoring of CTA 102 during high state in 2012 with OISTER: Detection of intra-night "orphan polarized flux flare"

Ryosuke Itoh, Yasushi Fukazawa, Yasuyuki T. Tanaka +35

CTA 102, classified as a flat spectrum radio quasar at z=1.037, produced exceptionally bright optical flare in 2012 September. Following Fermi-LAT detection of enhanced gamma-ray a…

astro-ph.EP2011★ 14 cited

Photometric Observations of 107P/Wilson-Harrington

Seitaro Urakawa, Shin-ichiro Okumura, Kota Nishiyama +14

We present lightcurve observations and multiband photometry for 107P/Wilson-Harrington using five small- and medium-sized telescopes. The lightcurve has shown a periodicity of 0.29…

astro-ph.GA2011★ 21 cited

Physical Relation of Source I to IRc2 in the Orion KL Region

Shin-ichiro Okumura, Takuya Yamashita, Shigeyuki Sako +4

We present mid-infrared narrow-band images of the Orion BN/KL region, and N-band low-resolution spectra of IRc2 and the nearby radio source "I." The distributions of the silicate a…

astro-ph.EP2010★ 93 cited

Thermo-physical properties of 162173 (1999 JU3), a potential flyby and rendezvous target for interplanetary missions

T. G. Mueller, J. Durech, S. Hasegawa +15

Near-Earth asteroid 162173 (1999 JU3) is a potential flyby and rendezvous target for interplanetary missions because of its easy to reach orbit. The physical and thermal properties…

astro-ph1999★ 4 cited

Possible Young Stellar Objects without Detectable CO Emission

Ikuru Iwata, Shin-ichiro Okumura, Mamoru Saito

We found that at least 18 Young Stellar Object candidates invisible at optical and near-infrared wavelengths, as well as ^12CO emission. They are IRAS point sources with FIR colors…