5 papers
Return of the Clocked Burster: Exceptionally Short Recurrence Time in GS 1826-238
Tomoshi Takeda, Toru Tamagawa, Teruaki Enoto +15
We report the discovery of an exceptionally short burst recurrence time in the well-known clocked burster GS 1826238, observed with the CubeSat X-ray observatory NinjaSat. In 20…
Thermonuclear superburst of MAXI J1752457 observed with NinjaSat and MAXI
Amira Aoyama, Teruaki Enoto, Takuya Takahashi +17
An uncatalogued bright X-ray transient was detected with MAXI on November 9, 2024, named MAXI J1752457. The NinjaSat X-ray observatory promptly observed the source from November…
Systematic study of the composition of Type I X-ray burst ashes: Neutron star structure v.s. Reaction rate uncertainties
Guoqing Zhen, Helei Liu, Akira Dohi +4
In this study, we calculate for the first time the impacts of neutron star(NS) structure on the type I X-ray burst ashes using the \texttt{MESA} code. We find an increased mass fra…
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…
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…