activity
20242026
collaborators

5 papers

astro-ph.SR2026

Evolution of Massive Main-sequence Stars in Rapid Population Synthesis. I. Framework and Implementation

Adam Brček, Ryosuke Hirai, Ilya Mandel +1

Stars spend most of their lifetime on the main sequence (MS), where hydrogen burning establishes the internal chemical structure that governs the subsequent evolution. In massive s…

astro-ph.SR2026

Mass transfer stability for AM CVn binaries with white dwarf donors

Lucy O. McNeill, Ryosuke Hirai

Double white dwarf binaries (DWDBs) with Helium components are progenitors to AM CVn binary systems. Their Galactic production rate may be given by the number of stably mass transf…

astro-ph.SR2025

Tidal heating in detached double white dwarf binaries

Lucy O. McNeill, Ryosuke Hirai

Short--period (1 hr orbits) detached double white dwarf binary (DWDB) components identified with transient surveys (e.g. SDSS, ZTF) have hot surface temperatures (10,000 K)…

astro-ph.HE2025

NinjaSat monitoring of Type-I X-ray bursts from the clocked burster SRGA J144459.2604207

Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +25

The CubeSat X-ray observatory NinjaSat was launched on 2023 November 11 and has provided opportunities for agile and flexible monitoring of bright X-ray sources. On 2024 February 2…

astro-ph.HE2024

Evidence of non-Solar elemental composition in the clocked X-ray burster SRGA J144459.2604207

Akira Dohi, Nobuya Nishimura, Ryosuke Hirai +13

In February and March 2024, a series of many Type I X-ray bursts from the accreting neutron star SRGA J144459.2604207, which has been identified by multiple X-ray satellites, wi…