Astroalert News
Katsumi Haseda
(Aichi, Japan; the discoverer of Nova Sct 2000 = V463 Sct, is
now renowned for his totally unexpected discovery of recurrent,
large variation of WR 104, the "pinwheel star", which
was reported in AstroAlert on the 2001 April 22 issue. He reports
the discovery of a large-amplitude new variable star (HadV84).
The star is again identified with an infrared- luminous WR-type
star, WR 106. Both in spectrum, in strong infrared excess, and
in other properties, the new variable star WR 106 = HadV84 is
a quite similar object to WR 104. The present discovery of a fading
with a depth more than two magnitudes suggests that the similar
mechanism is taking place in WR 106, as in WR 104, suggestion
of a new class of variable stars among Wolf-Rayet stars. Further
studies on these objects are keenly in progress, and we await
for your participation to VSNET in this exciting research!
For those
who have not read the April 22 issue, we cite the key reference
again: WR 104 is surrounded by a nebula, see also Tuthill et al.
1999, Nature 398, 487: "A dusty pinwheel nebula around the
massive star WR 104". (other on-line information can be read
at several internet site, e.g. http://www.isi.ssl.berkeley.edu/wr104.html)
WR 106 =
HadV84 = NSV10152 is located at 18h 04m 43.65s, -21o 09' 30.5"
(J2000.0). The star normally shines at V=11.9, but suddenly falls
below 13th magnitude, as experienced in R CrB-type variable stars.
The object is reported bright now (11.7 mag on April 22), but
may lose its light at any time. Continuous monitoring for future
events and quick announcement will be particular important for
astronomers who are trying to solve the mystery of these peculiar
Wolf-Rayet stars using huge and space telescopes.
We have been
undertaking on photometric campaigns on several super- outbursting
dwarf novae and peculiar variable stars like WR104.
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