Optical spectroscopy of V4641 Sgr
ATel #299; L. Kiss (University of Sydney), Sz. Meszaros (University of Szeged)
on 7 Jul 2004; 15:01 UT
Credential Certification: Laszlo Kiss (l.kiss@physics.usyd.edu.au)
Subjects: Optical, Request for Observations, Black Hole
Referred to by ATel #: 303
Optical spectra (range 600-690 nm; resolution 6000) were obtained
during the current outburst of this black hole binary on July 4.65-4.75 UT
with the Siding Spring 2.3-m telescope (+ DBS CCD spectrograph), right after the first visual
reports appeared via vsnet-obs and vsnet-alert. The spectra were dominated by a very strong
and broad H-alpha emission line with a full width at zero intensity of about 6000 km/s.
The He 6678 line was also in emission, showing two distinct components separated by 1000
km/s. Spectra in the blue (range 490-540 nm; resolution 10000) showed strong changes in the double-peaked emission profile of the He 5015 line over a period of 6 hours
(July 4.49-4.73 UT).
