17 citations · 34 across the 7 of their papers we have counts for
8 papers
A systematic study of quiescent and outburst properties of X-ray-bright young stellar objects using XMM-Newton
Koki Sakuta, Ikuyuki Mitsuishi, Seiya Sasamata +6
Young Stellar Objects (YSOs) exhibit strong X-ray emission, widely attributed to magnetic reconnection and magnetospheric accretion; however, owing primarily to limited photon stat…
Engulfment of a hot Jupiter as a possible origin of the rapid spin and internal spin misalignment of the planet-hosting red giant Kepler-56
Takato Tokuno
A recent asteroseismic analysis suggests that Kepler-56 -- a planet-hosting red giant -- exhibits a unique spin structure: (1) the spin axes of the core and envelope are misaligned…
Two unseen massive white dwarf candidates in close binaries
Yuta Shiraishi, Kenta Hotokezaka, Kento Masuda +10
We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TES…
Temporal Variation of Flare Occurrence Rates via the Spot Evolution on the Sun and Solar-type Stars
Takato Tokuno, Kosuke Namekata, Hiroyuki Maehara +1
The spot evolution on the Sun and solar-type stars is important for understanding the nature of consequential flaring activity. This study statistically investigates the variance o…
Effect of Magnetic diffusion in the Chromosphere on the Solar Wind
Masato Matsuoka, Takeru K. Suzuki, Takato Tokuno +1
We investigate non-ideal magnetohydrodynamical (MHD) effects in the chromosphere on the solar wind by performing MHD simulations for Alfvén-wave driven winds with explicitly includ…
A Novel Method to Constrain Tidal Quality Factor from A Non-synchronized Exoplanetary System
Takato Tokuno, Akihiko Fukui, Takeru K. Suzuki
We propose a novel method to constrain the tidal quality factor, , from an observed non-synchronized star-planet system consisting of a slowly rotating low-mass star and a clos…
Transition of latitudinal differential rotation as a possible cause of weakened magnetic braking of solar-type stars
Takato Tokuno, Takeru K. Suzuki, Munehito Shoda
We investigate the role of latitudinal differential rotation (DR) in the spin evolution of solar-type stars. Recent asteroseismic observation detected the strong equator-fast DR in…
Asteroseismology of the dip structure in period-spacings of rapidly rotating gamma Doradus stars caused by the coupling between core and envelope oscillations
Takato Tokuno, Masao Takata
Recent asteroseismic observations by the space mission have revealed the dip fine structure in the period-spacing versus period diagram of rapidly rotating Doradus…