The Astronomer's Telegram
Telegram Index | Search
To The Parent Site

[ Previous | Next ]

MAXI/GSC detects a spectral state transition in H 1743-322

ATEL # 2378; K. Yamaoka (AGU), H. Negoro (Nihon U.), M. Sugizaki, T. Mihara, M. Kohama, Y.E. Nakagawa, T. Yamamoto (RIKEN), M. Matsuoka, K. Kawasaki, S. Ueno, H. Tomida, M. Suzuki, M. Ishikawa (JAXA), N. Kawai, M. Morii, K. Sugimori (Tokyo Tech.), A. Yoshida, S. Nakahira (AGU), H. Tsunemi, M. Kimura (Osaka U.), M. Nakajima, R. Ishiwata, S. Miyoshi, H. Ozawa (Nihon U.), Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi (Kyoto U.), and A. Daikyuji (Univ. of Miyazaki), on behalf of the MAXI team
on 9 Jan 2010; 9:20 UT
Password Certification: Kazutaka Yamaoka (

Subjects: X-ray, Request for Observations, Binaries, Black Holes, Transients

MAXI/GSC has observed further brightening of the black hole candidate H 1743-322 in the current outburst (Yamaoka et al. ATEL #2364). The X-ray flux in the 4-10 keV band has been increasing from 83 mCrab on Jan. 3 (MJD 55199) to 180 mCrab on Jan. 7 (MJD 55203). The GSC energy spectra are roughly described with a single power-law with the absorption, and the photon index steepens from about 2.0 on Jan. 3 to about 3.1 on Jan. 7, suggesting that the source is just during the spectral state transition from the low/hard state to the very high or high/soft state. Further multi-wavelength observations are strongly encouraged.

The MAXI/GSC light curve and image are updated daily at the following URL:

[ Telegram Index ]

R. E. Rutledge , Editor
ATEL Mirror v1.0 Updates