765 citations · 1.2k across the 19 of their papers we have counts for
17 papers
Cosmic-ray ionization rate in protoplanetary disks with sheared magnetic fields
Yuri I. Fujii, Shigeo S. Kimura
We investigate the effects of magnetic field configurations on the ionization rate by cosmic rays in protoplanetary disks. First, we consider cosmic-ray propagation from the inters…
Six Outbursts of Comet 46P/Wirtanen
Michael S. P. Kelley, Tony L. Farnham, Jian-Yang Li +32
Cometary activity is a manifestation of sublimation-driven processes at the surface of nuclei. However, cometary outbursts may arise from other processes that are not necessarily d…
OGLE-2018-BLG-1185b : A Low-Mass Microlensing Planet Orbiting a Low-Mass Dwarf
Iona Kondo, Jennifer C. Yee, David P. Bennett +94
We report the analysis of planetary microlensing event OGLE-2018-BLG-1185, which was observed by a large number of ground-based telescopes and by the Space Telescope. The…
Cometary records revise Eastern Mediterranean chronology around 1240 CE
Koji Murata, Kohei Ichikawa, Yuri I. Fujii +4
Eirene Laskarina, empress of John III Batatzes of the exiled Byzantine Empire of Nicaea (1204--1261 CE), was an important Eastern Mediterranean figure in the first half of the thir…
Large-scale changes of the cloud coverage in the Indi Ba,Bb system
J. A. Hitchcock, Ch. Helling, A. Scholz +22
We present the results of 14 nights of \textit{I}-band photometric monitoring of the nearby brown dwarf binary, Indi Ba,Bb. Observations were acquired over 2 months, and total…
OGLE-2017-BLG-0406: Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk
Yuki Hirao, David P. Bennett, Yoon-Hyun Ryu +93
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the satellite in a solar…
Formation of single-moon systems around gas giants
Yuri I. Fujii, Masahiro Ogihara
Several mechanisms have been proposed to explain the formation process of satellite systems, and relatively large moons are thought to be born in circumplanetary disks. Making a si…
Transit timing variations in the WASP-4 planetary system
John Southworth, M. Dominik, U. G. Jorgensen +25
Transits in the planetary system WASP-4 were recently found to occur 80s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that…
Spitzer Microlensing parallax reveals two isolated stars in the Galactic bulge
Weicheng Zang, Yossi Shvartzvald, Tianshu Wang +90
We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-sour…
OGLE-2017-BLG-1186: first application of asteroseismology and Gaussian processes to microlensing
Shun-Sheng Li, Weicheng Zang, Andrzej Udalski +102
We present the analysis of the event OGLE-2017-BLG-1186 from the 2017 Spitzer microlensing campaign. This is a remarkable microlensing event because its source is photometrically b…
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
R. A. Street, E. Bachelet, Y. Tsapras +28
We report observations of the binary microlensing event OGLE-2018-BLG-0022, provided by the ROME/REA Survey, which indicate that the lens is a low-mass binary star consisting of M3…
Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-Rotating Low-Mass Brown Dwarf
Yossi Shvartzvald, Jennifer C. Yee, Jan Skowron +63
The kinematics of isolated brown dwarfs in the Galaxy, beyond the solar neighborhood, is virtually unknown. Microlensing has the potential to probe this hidden population, as it ca…
OGLE-2017-BLG-1434Lb: Eighth q < 1 * 10^-4 Mass-Ratio Microlens Planet Confirms Turnover in Planet Mass-Ratio Function
A. Udalski, Y. -H. Ryu, S. Sajadian +55
We report the discovery of a cold Super-Earth planet (m_p=4.4 +/- 0.5 M_Earth) orbiting a low-mass (M=0.23 +/- 0.03 M_Sun) M dwarf at projected separation a_perp = 1.18 +/- 0.10 AU…
The Emergence of a Lanthanide-Rich Kilonova Following the Merger of Two Neutron Stars
N. R. Tanvir, A. J. Levan, C. Gonzalez-Fernandez +51
We report the discovery and monitoring of the near-infrared counterpart (AT2017gfo) of a binary neutron-star merger event detected as a gravitational wave source by Advanced LIGO/V…
Orbital Evolution of Moons in Weakly Accreting Circumplanetary Disks
Yuri I. Fujii, Hiroshi Kobayashi, Sanemichi Z. Takahashi +1
We investigate the formation of hot and massive circumplanetary disks (CPDs) and the orbital evolution of satellites formed in these disks. Because of the comparatively small size-…
On the Viability of the Magnetorotational Instability in Circumplanetary Disks
Yuri I. Fujii, Satoshi Okuzumi, Takayuki Tanigawa +1
We examine whether the magnetorotational instability (MRI) can serve as a mechanism of angular momentum transport in circumplanetary disks. For the MRI to operate the ionization de…
A Fast and Accurate Calculation Scheme for Ionization Degrees in Protoplanetary and Circumplanetary Disks with Charged Dust Grains
Yuri I. Fujii, Satoshi Okuzumi, Shu-ichiro Inutsuka
We develop a fast and accurate calculation method for ionization degrees in protoplanetary and circumplanetary disks including dust grains. We apply our method to calculate the ion…