[vsnet-alert 8647] (fwd) V725 Tau = A0535+26, renewed X-ray activity (ATEL)

[Taichi Kato]

   A0535+26 = V725 Tau, now easily visible in the morning sky!

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The Astronomer's Telegram                   http://www.astronomerstelegram.org 
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ATEL #595							     ATEL #595

Title:		Renewed Activity from A 0535+26
Author:	Mark H. Finger (National Space Science and Technology Center/USRA)
Queries:	mark.finger at nsstc.nasa.gov
Posted:	27 Aug 2005;  19:58  UT
Subjects:	X-ray, Binaries, Neutron Stars, Pulsars, Transients

A short observation of A 0535+26 on August 26.7 with the RXTE/PCA shows
this nearby Be/X-ray pulsar at a flux of approximately 20 mCrab (2-10 keV).
Pulsations consistent with a period of ~103 s were present, as was a high
level of aperiodic variability.      The source had a major outburst in
May and June 2005 which, because of the closeness of the sun, was observed
by only a few instruments (ATEL #504, ATEL #557). In the RXTE/ASM light-curve
A0535+26 was detected from May 6th to June 24, and had a peak flux above
103 c/s (1.4 Crab). A PCA observation on July 27.0 found a flux of about
2 mCrab (2-10 keV).      The recent PCA detection is approximately one
orbital period (111 days, Motch et al. 1991, ApJ 369, 490) after the June
24 ASM detection. Another major outburst is possible. Further observations
are scheduled with RXTE, and observations with other instruments are encouraged.

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