文件操作 - 1750921511.M232123P9359.mail.planetcloud-host.com,S=4711,W=4804:2,

文件: /var/vmail/bicar.it/stefano/cur/1750921511.M232123P9359.mail.planetcloud-host.com,S=4711,W=4804:2,

编辑文件内容

Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=174.142.199.243; helo=server.astronomerstelegram.org; envelope-from=atel@astronomerstelegram.org; receiver=stefano@bicar.it 
To: stefano@bicar.it
From: atel@astronomerstelegram.org
Subject: ATel  17245
Message-Id: <20250626070507.AD36B28808CE@server.astronomerstelegram.org>
Date: Thu, 26 Jun 2025 03:05:07 -0400 (EDT)

------------------------------------------------------------------------------ 
The Astronomer's Telegram is free to read, free to publish, free to
use.  Thanks to the support of our patrons, we can continue to
keep it free. https://www.patreon.com/astronomerstel
------------------------------------------------------------------------------ 
The Astronomer's Telegram                   http://www.astronomerstelegram.org 
------------------------------------------------------------------------------
Posted: Within the last 24 hours
==============================================================================
ATEL #17245							     ATEL #17245

Title:	Return of the clocked burster GS 1826-238
Author:	S. Iwata, N. Ota, T. Kita, K. Yamasaki, S. Tsuchiya, Y. Nakano,
		M. Ichibakase, T. Takeda, A. Aoyama, T. Takahashi (TUS/RIKEN), T.
		Tamagawa (RIKEN/TUS), T. Enoto (Kyoto U./RIKEN), W. Iwakiri (Chiba
		U.), T. Kitaguchi (RIKEN), C.-P. Hu (NCUE), T. Mihara (RIKEN), and
		the NinjaSat team
Queries:	tamagawa@riken.jp
Posted:	25 Jun 2025; 10:32 UT
Subjects:X-ray, Neutron Star, Transient

NinjaSat observed the neutron star low-mass X-ray binary GS 1826-238 from
2025-06-23 13:05 UT to 2025-06-24 13:53 UT with a total exposure of 15.3
ks, and detected six Type-I X-ray bursts. The intervals between the first
five bursts were nearly constant at approximately 1.6 hours, suggesting
that GS 1826-238 may have entered a clocked burster state for the first
time in 10 years. This is the shortest burst recurrence period ever measured
for GS 1826-238 in its clocked burster state.

GS 1826-238 remained in the hard state from 1996 until 2014. Between 1997
and 2007, it exhibited a clocked burster state with burst recurrence times
of 3 to 6 hours, as reported by Thompson et al. (ApJ 681, 506, 2008), earning
it the nickname "textbook burster". Around 2013, the source gradually brightened
and transitioned to the soft state after 2014 (Fig. 12 in Asai et al.,
PASJ 74, 974, 2022). According to observations by Swift/BAT and MAXI, the
intensity of GS 1826-238 gradually decreased since 2025-05-25, and transitioned
back to the hard state on 2025-06-11. MAXI detected an X-ray burst from
the source at 2025-06-20 14:37 UT.

The burst onset times in MJD detected by NinjaSat are as follows:

60849.5464

60849.6135

60849.6805

60849.7474

60849.8125

60850.1932

Follow-up observations are encouraged, as GS 1826-238 is expected to remain
in the hard state, with further clocked X-ray bursts.

NinjaSat is a 6U-size X-ray CubeSat with Xe-filled proportional counters
covering the energy range of 2-50 keV, focusing on agile observations of
bright X-ray compact sources (Tamagawa et al., PASJ 77, 466, 2025).

------------------------------------------------------------------------------
Password Certification: Tatehiro Mihara (mihara@crab.riken.jp)
https://www.astronomerstelegram.org/?read=17245
==============================================================================

==============================================================================
This is an automatically-generated notice.  You can remove yourself permanently
from receiving both the Daily Email Digest and Instant Email Notices from
The Astronomer's Telegram by following this link:
https://www.astronomerstelegram.org?unsubscribe&confirmation=a803d34e7ea924f9a4142bac00763549&address=stefano@bicar.it

文件操作 - 1750921511.M232123P9359.mail.planetcloud-host.com,S=4711,W=4804:2,

文件: /var/vmail/bicar.it/stefano/cur/1750921511.M232123P9359.mail.planetcloud-host.com,S=4711,W=4804:2,

编辑文件内容

修改文件时间

删除文件