4 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…
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…
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…
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…