40 citations · 105 across the 17 of their papers we have counts for
17 papers
A Search for helium in the atmospheres of three sub-Neptunes and a super-Earth around M-dwarfs
Kiyoe Kawauchi, Norio Narita, Yuichi Ito +26
Thousands of sub-Neptunes have been discovered mainly through space-based surveys such as Kepler and TESS. Their bulk compositions and internal structures are thought to reflect th…
Discovery of an Eccentric Hot Super-Jupiter Leaving the Transiting Geometry of the Early-A-type star TOI-1355
Noriharu Watanabe, Norio Narita, Akihiko Fukui +20
Hot Jupiters orbiting hot stars ( K) are suggested to have experienced high-eccentricity migration, often evidenced by the tendency for misaligned orbits, de…
Observing a 542-day transiting giant with large TTVs: The 2025 transit of HIP 41378 f and new constraints on the outer system
Pietro Leonardi, Alexandre Santerne, Luca Borsato +27
Characterizing long-period transiting exoplanets is inherently challenging due to the rarity and long duration of transit events. Yet, these systems provide unique insights into pl…
The mass of TOI-1883 b: A low density super-Neptune in the ridge regime transiting an early-M dwarf
Izuru Fukuda, Norio Narita, Akihiko Fukui +36
Recent large-scale transit surveys conducted by space telescopes such as Kepler and TESS have revealed a vast number of exoplanets, uncovering the diversity of their population. On…
Gas-depleted planet formation occurred in the four-planet system around the red dwarf LHS 1903
Thomas G. Wilson, Anna M. Simpson, Andrew Collier Cameron +173
Small exoplanet radii show two populations, referred to as super-Earths and sub-Neptunes, separated by a gap known as the radius valley. This may be produced by the removal of atmo…
Identifying close-in Jupiters that arrived via disk migration: Evidence of primordial alignment, preference of nearby companions and hint of runaway migration
Yugo Kawai, Akihiko Fukui, Noriharu Watanabe +2
Two leading hypotheses for hot Jupiter migration are disk migration and high-eccentricity migration (HEM). Stellar obliquity is commonly used to distinguish them, as high obliquity…
The mass of TOI-654 b: A short-period sub-Neptune transiting a mid-M dwarf
Kai Ikuta, Norio Narita, Takuya Takarada +40
Sub-Neptunes are small planets between the size of the Earth and Neptune. The orbital and bulk properties of transiting sub-Neptunes can provide clues for their formation and evolu…
Multi-band, Multi-epoch Photometry of the Spot-crossing System TOI-3884: Refined System Geometry and Spot Properties
Mayuko Mori, Akihiko Fukui, Teruyuki Hirano +10
Spot-crossing transits offer a unique opportunity to probe spot properties such as temperature, size, and surface distribution. TOI-3884 is a rare system in which spot-crossing fea…
Tidally Heated Sub-Neptunes, Refined Planetary Compositions, and Confirmation of a Third Planet in the TOI-1266 System
Michael Greklek-McKeon, Shreyas Vissapragada, Heather A. Knutson +38
TOI-1266 is a benchmark system of two temperate ( 450 K) sub-Neptune-sized planets orbiting a nearby M dwarf exhibiting a rare inverted architecture with a larger interior plane…
Low abundances of TiO and VO on the Dayside of KELT-9 b: Insights from Ground-Based Photometric Observations
Yuya Hayashi, Norio Narita, Akihiko Fukui +21
We present ground-based photometric observations of secondary eclipses of the hottest known planet KELT-9b using MuSCAT2 and Sinistro. We detect secondary eclipse signals in an…
Obliquities of Exoplanet Host Stars: 19 New and Updated Measurements, and Trends in the Sample of 205 Measurements
Emil Knudstrup, Simon H. Albrecht, Joshua N. Winn +17
Measurements of the obliquities in exoplanet systems have revealed some remarkable architectures, some of which are very different from the Solar System. Nearly 200 obliquity measu…
Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3
Michaël Gillon, Peter P. Pedersen, Benjamin V. Rackham +81
Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary p…
Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
M. Kuzuhara, A. Fukui, J. H. Livingston +103
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…
The Discovery and Follow-up of Four Transiting Short-period Sub-Neptunes Orbiting M dwarfs
Y. Hori, A. Fukui, T. Hirano +100
Sub-Neptunes with are intermediate in size between rocky planets and Neptune-sized planets. The orbital properties and bulk compositions of transiting sub-Neptunes pr…
Characterization of starspots on a young M-dwarf K2-25: multi-band observations of stellar photometric variability and planetary transits
Mayuko Mori, Kai Ikuta, Akihiko Fukui +13
Detailed atmospheric characterization of exoplanets by transmission spectroscopy requires careful consideration of stellar surface inhomogeneities induced by starspots. This effect…
The flipped orbit of KELT-19Ab inferred from the symmetric TESS transit light curves
Yugo Kawai, Norio Narita, Akihiko Fukui +2
Dozens of planets are now discovered with large orbital obliquity, and have become the proof for the dynamical evolution of planetary orbits. In the current samples, there is an ap…
VaTEST III: Validation of 8 Potential Super-Earths from TESS Data
Priyashkumar Mistry, Aniket Prasad, Mousam Maity +29
NASA's all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has succe…