The High Mass X-ray binary V0332+53 (discovered in 1973 with
Vela 5B) was observed during
an outburst by INTEGRAL on Jan 7-10. Two observations were made: a 30 ks staring
observation and a 70 ks hexagonal dithering observation.
The source was outside the visible area defined by the viewing
constraints in the standard 5x5 dither pattern until the
end of January. Given the general interest for the source,
its scientific importance, and the lack of an approved proposal
INTEGRAL data of the source was made public immediately.
Further observations were done later in January.
The picture of the month shows in the top panel the
raw spectrum of JEM-X (black), IBIS (red) and SPI (blue)
were two (or perhaps three) cyclotron absorption lines
are clearly visible. Detailed analysis reveals the presence of a
cyclotron line with three harmonics with energies of 24.9,
50.5, and 71.7 keV.
In the bottom panel the magnitude of the optical companion
derived from the OMC instrument on-board INTEGRAL is displayed.
The horizontal blue lines indicate the variability range as
reported in the literature.
Credits: I. Kreykenbohm (IAAT/ISDC) and J. Miguel Mas Hesse (LAEFF).
