New Outburst of MXB 1730-335
ATel #57; Derek W. Fox & Walter H. G. Lewin (MIT)
on 26 Mar 2000; 23:27 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Derek W. Fox (derekfox@mit.edu)
Subjects: Radio, Infra-Red, X-ray, Request for Observations, Binary, Neutron Star, Transient
A Rossi X-ray Timing Explorer Proportional Counter Array (2-60
keV) observation of the source 4U 1728-34, beginning 25 March 2000
20:35 UT, has revealed the Rapid Burster (MXB 1730-335) to be in
outburst. Strong (10,000 PCA cts/sec ~ 0.8 Crab) flat-topped bursts,
lasting 100-300 seconds and repeating at 500-1000 second intervals,
were observed along with >1000 PCA cts/sec (100 mCrab) persistent
emission.
This behavior is similar to that observed at the start of the August
1998 outburst (ATEL #32), and represents the strongest type II bursts
observed from this source in the RXTE era. The strength of the
bursts is expected to decrease over the course of the next two weeks
as the outburst evolves (Guerriero et al. 1999).
High time resolution (<10 sec) infrared observations of the source
during the next week may reveal IR counterparts to the type II X-ray
bursts, since these are expected to reach K < 16.5. Please contact the
authors to arrange possible coordination with RXTE observations
(see also the Rapid
Burster Page).
The coordinates of the Rapid Burster's (likely) VLA counterpart (Moore et al. 2000)
are RA=17h33m24s.61; Dec=-33d23m19s.8 (J2000).
Rapid Burster Page
