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[vsnet-campaign-news 29] News from VSNET 29
*** News from VSNET ***
An eclipse of Delta Vel is predicted to be occur on November 21.
DO Dra showed a rare outburst, and then, rapidly faded.
For more detail information about these objects,
see below, "VSNET Weekly Campaign Summary" of the last week.
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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.
CCD observations of such targets are a relatively easy task for a 20-40cm
telescope; simply take as many CCD frames (with exposure times 10-30 sec)
as possible, spanning several hours per night. The only requirements are
the weather and your patience! If you need more help on the observing
technique, please feel free to ask on the vsnet-campaign list.
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).
Regards,
Taichi Kato
On behalf of the VSNET administrator team
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The following was issued on Nov. 21, 2000, as VSNET campaign circulation 559.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
RU Hor (RA = 02h46m05s.38, Dec = -63d35'04".0)
R. Stubbings reported that the dwarf nova RU Hor experienced a
relatively rare outburst on November 14 (13.8mag).
The last reported outburst occurred in 1999 August. The object has a
relatively large outburst amplitude (>5 mag?), which would make it
a good candidate for an SU UMa-type dwarf nova (vsnet-campaign 556).
The object have faded rather rapidly. R. Stubbings reported it was
fainter than 14.4mag on November 17 (vsnet-campaign-dn 247).
KK Tel (RA = 20h28m37s.27, Dec = -52d18'25".1)
R. Stubbings reported that the dwarf nova KK Tel experienced an
outburst on November 14 (13.9mag). This star is a candidate
SU UMa-type dwarf nova suspected from quiescent photometry. The last
long outburst occurred in 2000 May (vsnet-campaign 557). The object have
faded rather rapidly. R. Stubbings reported it was fainter than 15.0mag
on November 17 (vsnet-campaign-dn 248).
DO Dra (RA = 11h43m38s.5, Dec = +71d41'19".1)
As reported by C. Jones, P. Schmeer and other observers, the intermediate
polar with rare dwarf nova-type(-like?) outbursts showed a major
outburst on November 16 (about 11mag; vsnet-campaign 558).
R. Ishioka, Kyoto team performed a time-series photometry at Kyoto on
November 17 and found the object became fainter than the peak (R=11.4mag;
vsnet-campaign-ip). K. Mukai and his collaborators are planning TOO
observations of DO Dra with the RXTE satellite on November 19, 20, and 21
(vsnet-campaign-ip 4). The object have rapidly faded. The current
magnitude seems to be fainter than 13mag (vsnet-campaign-ip 7).
(continuous targets)
SN 2000dx (RA = 02h18m26s.88, Dec = +05d39'02".0)
Reported magnitudes were brighter than expected (vsnet-campaign-sn 110),
and the brightness seems to pass a peak.
Delta Vel (RA = 08h44m42s.1, Dec = -54d42'30")
S. Otero wrote in [vsnet-campaign-deltavel 26] that the next eclipse
is predicted to occur on November 21.54 (UT), and more detailed comments
for observations are presented. In [vsnet-campaign-deltavel 27],
A. Jansen wrote that taking into account that the eclipse will start
about 11 hours before and end about 11 hours after minimum, the observing
window must stretch from November 20th, 9h UT until November 22nd, 1h UT.
BL Lac (RA = 22h02m42.86s, Dec = +42d16'37.6")
The object again flared up during the last week (vsnet-campaign-blazar 92).
The object was observed at 13.3 mag on November 17. The data suggests
a jump by a magnitude within a day (vsnet-campaign-blazar 93).
IP Peg (RA = 23h23m08s.7, Dec = +18d24'59".1)
The last long outburst lasted for about 2 weeks and now it is at
quiescence (vsnet-campaign-dn 242).
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
S. Otero found that taking the orbital period from Fabregat, Reig and
Tarasov (2000) P= 10.583 and the ephemeris from Hartkopf et al.,(1996)
To = 1979.41 , a periastron passage had taken place in 1958.24, and
the star was measured brighter than normal in 1958. He also commented
it's a very good indicator of the relation between the binary nature of
the system and the observed events (vsnet-campaign-be 71).
DM Dra (RA = 15h34m01s.33, Dec = +59d47'02".0)
T. Kato performed the photometry of the time-series data on DM Dra on
October 27, observed by K. Matsumoto, the Kyoto team. The observation
covered 0.091 d and there is a hint of a maximum during the early part
of the observing run. However, the amplitude of superhumps (if exists)
did not much exceed 0.1 mag (vsnet-campaign-dn 243).
RX J2315.5-3049 (RA = 23h15m31s.934, Dec = -30d48'45".53)
T. Kato analyzed the time-series data on RX J2315.5-3049 on October 27,
observed by K. Matsumoto, the Kyoto team. The analysis perfectly confirms
the existence and the phasing of humps reported in [vsnet-alert 5344].
The outburst was unusually short for a superoutburst, although the
detected hump signature in outburst bore all characteristics of superhumps
(vsnet-campaign-dn 244).
*** Future schedule ***
DO Dra: RXTE TOO observation on November 19, 20, and 21
In [vsnet-campaign-ip 4], K. Mukai wrote:
Dr. Szkody has pointed out that, during the last outburst, X-ray and
optical spin pulses were out of phase. We would therefore like to
request all observers capable of fast photometry to obtain as much
data as weather etc. permit --- this system has a 530 s spin period,
but most of the modulations are at 1/2 the spin period and its orbital
sideband. Simultaneous photometry with RXTE would be particularly
valuable; even if not simultaneous, any data that would allow us to
track the evolution of spin modulation during the outburst decay
would be highly useful.
*** General information ***
Delta Vel
detailed information for observations by S. Otero,
see [vsnet-campaign-deltavel 26]
(This summary is reproduction free.)
Regards,
Makoto Uemura
vsnet-adm@kusastro.kyoto-u.ac.jp
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page