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[vsnet-campaign-news 1] News from VSNET No. 1
*** News from VSNET ***
VSNET (Variable Star Network) is an international variable star observing
network, covering various areas of novae, supernovae, cataclysmic variables
(CVs), X-ray transients, and other classical eruptive, pulsating, and
eclipsing variables. VSNET is one of invited contributing organizations
to the SkyPub AstroAlert system.
The "News from VSNET", mainly focusing on recent remarkable activities of
CVs and related systems, is issued on a weekly basis, except on occasions
of extremely urgent or transient events.
Please refer to the VSNET Home Page for more details of events and
objects listed.
VSNET Home Page: http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/
VSNET provides a number of mailing lists, on which various news and topics
are discussed. Subscriptions to the VSNET mailing lists are free of charge;
please refer to the instruction on the above page if a reader needs more
information of the list structure.
Regards,
Taichi Kato
On behalf of the VSNET administrator team
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The following was issued on May 15, 2000, as VSNET campaign circulation 65.
XTE J1118+480 is the unusual X-ray nova in Ursa Major (IAUC 7389),
whose optical counterpart was discovered by the VSNET team and announced
as vsnet-alert 4503 and IAUC 7390. The object maintains the bright state
at around magnitude 12.8.
CI Aql is the recurrent nova (= Nova Aql 1917, 2000), whose first-ever
recurrence was discovered by Takamizawa and Yamamoto, whose detection
and confirmation was announced via vsnet-alert 4695 and IAUC 7409.
The object is slowly fading around magnitude 10.0.
We would sincerely appreciate volunteers who would join the VSNET
Collaboration team to study the wonders of these exotic variable stars.
To join the VSNET campaign collaborative list, send an e-mail to
vsnet-adm@kusastro.kyoto-u.ac.jp (VSNET administrator)
with a line "SUBSCRIBE vsnet-campaign."
(VSNET campaign members are strongly recommended to subscribe to vsnet-alert
at the same time).
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(This is a summary of vsnet-campaign and vsnet-alert last week.)
Weekly Campaign Summary
*** Last week news ***
XTE J1118+480
The about 4-hour periodic variation is still seen in the light
curve, however, the profile has been changed from sinusoidal curve
to superhump-like shape. The evolution of humps is ongoing
(vsnet-campaign 5,21). The object showed a slight decline from
the end of April (vsnet-alert 4796).
"ASCA - VSNET multiwavelength campaign on XTE J1118+480" was
performed on 11 May (vsnet-campaign 10). ASCA had successful
observations and many observers joined the campaign. Unfortunately,
some site could not observe due to rain, however, we have already
received the simultaneous data from Nyrola team and Y. Sano and
V. Simon and R. Novak reported the successful observation
(vsnet-campaign 36,41). On the other days data, we have received
from L. Cook, D. Buczynski, B. Martin, G. Masi, Nyrola team, R. Novak,
and Y. Sano.
The period of short-time fluctuation and the current feature of
longer period variation are poorly unknown.
CI Aql
From the data on 5 May at Kyoto, it was suggested a relatively
large phase offset may be necessary from proposed eclipse ephemeris
(vsnet-campaign 7). A possible secondary eclipse was observed on
8 May at Kyoto and Tsukuba (vsnet-campaign 16). The object kept
the roughly constant magnitude of 9.1 in early May, and then,
showed decline (vsnet-alert 4802). The magnitude is currently
about 10mag. We have received four very extensive sets of time-series
from L. Kral on 15 May.
The complete eclipse light curve cannot be seen yet.
BZ UMa
As reported in [vsnet-outburst 2] and described in [vsnet-alert 4827],
the outburst of suspected SU UMa-type dwarf nova BZ UMa was detected
by G. Hanson (10.5mag on 13 May). R. Novak reported a rapid fading
indicating the outburst is a normal one (vsnet-campaign 47), and
E. Pavlenko, M. Moilanen, and A. Oksanen confirmed it (vsnet-campaign 51,54).
Please keep monitorings for the case of the transition to
superoutburst.
RX J0640-24
As reported by Rod Stubbings and Berto Monard in vsnet-outburst
messages, the ROSAT-selected suspected SU UMa-type star RX J0640-24
is in outburst (vsnet-campaign 49). The brightness on 13.396 UT was 11.8.
The superhump detection is expected.
RX J1450.5+6403
T. Vanmunster discovered an outburst of RX J1450.5+6403 on 14 May
at 14.4mag (vsnet-alert 4834). D. Nogami confirmed the object to
be in quiescence on May 11.10 (UT) (vsnet-alert 4837). T. Vanmunster
detected superhumps with the period of 0.0617d, and revealed the
current outburst is a superoutburst of a newly discovered SU UMa-type
dwarf nova.
*** This week schedule ***
NGC 4151 ASCA-VSNET multiwavelength campaign
from May 12 12:00 to May 24 24:00 (UT),
for more detail, see [vsnet-campaign 61,62]
near-IR observation on XTE J1118+480 with 1.23m CAHA
(by Dr. Alberto Castro-Tirado)
16-20 May (20:00-05:00 UT),
for more detail, see [vsnet-campaign 63]
*** General information ***
XTE J1118+480
recommended comparison star and more UBVRI sequence information:
see [vsnet-campaign 11]
CI Aql
eclipse ephemeris, see [vsnet-campaign 18]
BZ UMa
Visual observations - AFOEV database was posted in [vsnet-campaign 45]
or see, http://astro.u-strasbg.fr/afoev
RX J1450.5+6403
location and RASS, USNO identification,
see [vsnet-alert 4834,4835,4836]
Regards,
Makoto Uemura
vsnet-adm@kusastro.kyoto-u.ac.jp
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page