103 citations · 287 across the 13 of their papers we have counts for
13 papers
JASMINE: Near-Infrared Astrometry and Time Series Photometry Science
Daisuke Kawata, Hajime Kawahara, Naoteru Gouda +86
Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aero…
Modeling photometric variations due to a global inhomogeneity on an obliquely rotating star: application to lightcurves of white dwarfs
Yasushi Suto, Shin Sasaki, Masataka Aizawa +2
We develop a general framework to compute photometric variations induced by the oblique rotation of a star with an axisymmetric inhomogeneous surface. We apply the framework to com…
3-D selection of 167 sub-stellar companions to nearby stars
Fabo Feng, R. Paul Butler, Steven S. Vogt +20
We analyze 5108 AFGKM stars with at least five high precision radial velocity points as well as Gaia and Hipparcos astrometric data utilizing a novel pipeline developed in previous…
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…
ET White Paper: To Find the First Earth 2.0
Jian Ge, Hui Zhang, Weicheng Zang +163
We propose to develop a wide-field and ultra-high-precision photometric survey mission, temporarily named "Earth 2.0 (ET)". This mission is designed to measure, for the first time,…
Global Mapping of Surface Composition on an Exo-Earth Using Sparse Modeling
Atsuki Kuwata, Hajime Kawahara, Masataka Aizawa +2
The time series of light reflected from exoplanets by future direct imaging can provide spatial information with respect to the planetary surface. We apply sparse modeling to the r…
Dippers from TESS Full-frame Images. II. Spectroscopic Characterization of Four Young Dippers
Yui Kasagi, Takayuki Kotani, Hajime Kawahara +9
Photometric monitoring by the Transiting Exoplanet Survey Satellite (TESS) has discovered not only periodic signals by transiting exoplanets but also episodic or quasi-periodic dim…
Dippers from the TESS Full-Frame Images I: The Results of the first 1 year data and Discovery of A Runaway dipper
Tomoyuki Tajiri, Hajime Kawahara, Masataka Aizawa +9
We present a comprehensive catalog of the dippers---young stellar objects that exhibit episodic dimming---derived from the one year's worth of data of Transiting Exoplanet Survey S…
Search for Alignment of Disk Orientations in Nearby Star-Forming Regions: Lupus, Taurus, Upper Scorpius, Ophiuchi, and Orion
Masataka Aizawa, Yasushi Suto, Yoko Oya +2
Spatial correlations among proto-planetary disk orientations carry unique information on physics of multiple star formation processes. We select five nearby star-forming regions th…
Global Mapping of an Exo-Earth using Sparse Modeling
Masataka Aizawa, Hajime Kawahara, Siteng Fan
We develop a new retrieval scheme for obtaining two-dimensional surface maps of exoplanets from scattered light curves. In our scheme, the combination of the L1-norm and Total Squa…
Systematic Search for Rings around Kepler Planet Candidates: Constraints on Ring Size and Occurrence Rate
Masataka Aizawa, Kento Masuda, Hajime Kawahara +1
We perform a systematic search for rings around 168 Kepler planet candidates with sufficient signal-to-noise ratios that are selected from all the short-cadence data. We fit ringed…
Towards Detection of Exoplanetary Rings Via Transit Photometry: Methodology and a Possible Candidate
Masataka Aizawa, Sho Uehara, Kento Masuda +2
Detection of a planetary ring of exoplanets remains as one of the most attractive but challenging goals in the field. We present a methodology of a systematic search for exoplaneta…
Transiting Planet Candidates Beyond the Snow Line Detected by Visual Inspection of 7557 Kepler Objects of Interest
Sho Uehara, Hajime Kawahara, Kento Masuda +2
We visually inspected the light curves of 7557 Kepler Objects of Interest (KOIs) to search for single transit events (STEs) possibly due to long-period giant planets. We identified…