Issue |
A&A
Volume 699, July 2025
|
|
---|---|---|
Article Number | A130 | |
Number of page(s) | 11 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/202553748 | |
Published online | 01 July 2025 |
An investigation into the X-ray bursts in Cir X-1
1
College of Physics and Electronic Engineering, Qilu Normal University, 250200 Jinan, People’s Republic of China
2
Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing, People’s Republic of China
3
Dongguan Neutron Science Center, 1 Zhongziyuan Road, Dongguan 523808, People’s Republic of China
4
School of Astronomy and Space Science and Key Laboratory of Modern Astronomy and Astrophysics, Nanjing University, 210023 Nanjing, People’s Republic of China
5
University of Chinese Academy of Sciences, Chinese Academy of Sciences, 100049 Beijing, People’s Republic of China
⋆ Corresponding authors: yuzl@ihep.ac.cn, szhang@ihep.ac.cn
Received:
14
January
2025
Accepted:
25
May
2025
We report 155 X-ray bursts from Cir X-1 detected with NICER and 48 with Insight-HXMT, respectively. The K-medoids clustering algorithm was applied to X-ray bursts detected by NICER for classification. These X-ray bursts are classified into two categories, designated as Class A and B. The profile of Class A resembles that of a typical type I X-ray burst. Class B is weaker and its profile is approximately symmetric. In these X-ray bursts, the shortest recurrence time of ∼300 s observed to date in Cir X-1 is detected. Additionally, no burst is detected prior to MJD 58933 in NICER and Insight-HXMT. The underlying reason for this phenomenon remains unclear and requires further investigation.
Key words: binaries: general / stars: individual: Cir X-1 / X-rays: bursts
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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