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[vsnet-campaign-news 14] New from VSNET 14
*** 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 spectacular event announced in the last week news - the HISTORICAL
OUTBURST of delta Scorpii - is still ongoing, but has faded a little.
Observers are strongly recommende to watch the further progress of the
activity, since the 1937 outburst of gamma Cas was reported to be double-
peaked. The following URLs will help visiting this star.
* Charts with magnitudes (created by Tsutomu Watanabe, VSOLJ):
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-j-deltasco/msg00011.html
(The main text is in Japanese, but the image will look ok).
* Latest light curve (requires Java):
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/etc/drawobs.cgi?text=SCOdelta
The key VSNET lists on delta Sco are vsnet-be and vsnet-campaign-be.
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-be/maillist.html
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-campaign-be/maillist.html
The halo(?) black-hole transine, XTE J1118+480, has finally entered
the rapid decline stage. Intensive observations are strongly encouraged
to follow the subsequent behavior. Several X-ray transiens had post-outburst
brightenings. The best case is GRO J0422+32 = V518 Per. An analoygy to
WZ Sge-type SU UMa-type dwarf novae has been suggested by several authros.
See the representative page of such a dwarf nova:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/egcnc.html
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).
Or, look at the list information page for more details:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/information.html
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The following was issued on Aug. 7, 2000, as VSNET campaign circulation 414.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V730 Sgr (RA = 19h23m00s.79, Dec = -28d29'29".2)
As report by Williams in [vsnet-alert 5167], the suspected dwarf nova
V730 Sgr was in outburst (13.6mag on August 4). The first outburst reported
to VSNET was in 1998 May, by Stubbings (mv=13.8) (vsnet-campaign 409).
The data observed by N. Butterworth can be seen in [vsnet-campaign-data 34]
and T. Kato commented about the data that the data seems to indicate the
absence of variations greater than 0.1 mag (vsnet-campaign 412).
More time-series photometry is needed to clarify the sub-type of this
object.
SN 2000da (RA = 00h03m06s.52, Dec = -01d54'41".8)
This supernova was discovered by the Lick Observatory team (IAUC 7474).
H. Yamaoka reported that the recession velocity of UGC 5 (the host galaxy
of SN 2000da) is 7271 km/s, from which the expected maximum of typical
SN Ia is about 16.6 mag (vsnet-campaign-sn 38).
Close monitorings are encouraged.
(continuous targets)
SY Vol (RA = 08h53m28s.9, Dec = -71d12'29".9)
The outburst has faded since July 31 (vsnet-campaign-dn 74).
Now it is at quiescent state.
BR Lup (RA = 15h35m51s.61, Dec = -40d34'25".4)
The superoutburst continues. The current magnitude is about 14.0mag
(vsnet-campaign-dn 98). Time-series observations are strongly encouraged.
V1008 Her (RA = 18h05m46s.4, Dec = +31d40'18")
T. Vanmunster performed an unfiltered CCD photometry on July 30/31
and reported that the resulting light curve is flat, showing no periodic
modulations. With his past run, he commented that this outbursting
object seems to be an UGSS type dwarf nova (vsnet-campaign 406).
The long outburst finally began fading from August 4 (13.7mag by
M. Reszelski)(vsnet-campaign-dn 95).
DH Aql (RA = 19h26m12s.05, Dec = -10d15'21".4)
H. Iwamatsu and T. Kato performed CCD photometry on this SU UMa-type
dwarf nova under superoutburst on August 2, and confirmed that the object
was still bright (vsnet-campaign-dn 81). From the light curve obtained
through August 3 observation at Ouda station by H. Iwamatsu and T. Kato,
they revealed that there were fully grown superhumps with the amplitude
of 0.30mag (vsnet-campaign-dn 92). They calculated the superhump period
with the data on August 3, 4, and 5 to be 0.07991 d (vsnet-campaign-dn 99).
It is still in superoutburst and the current magnitude is about 12.7mag.
More observations are strongly encouraged.
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
E. Pollmann reported the equivalent width of H-alpha line on July 30
to be 1.9 and 1.6 A derived from the two spectra (vsnet-campaign-be 21).
The object may show slightly fading (vsnet-campaign-be 31).
V4641 Sgr (RA = 18h19m21s.6, Dec = -25d24'25")
No prominent activity was reported (vsnet-campaign-xray 27,30,31).
SN 2000cx (RA = 01h24m46s.15, Dec = +09o30'30".9)
This supernova reached the maximum at about 13.1mag around the end of July
(vsnet-campaign-sn 36), and then, started fading (vsnet-campaign-sn 39).
The current magnitude is about 13.9mag.
1H 1933+510 (RA = 19h34m36s.08, Dec = +51d07'42".2)
After this new likely dwarf nova (originally NL type) returned to
low-state, another outburst was reported by S. O'Connor at 15.8mag
on August 4 (vsnet-campaign 408). T. Vanmunster performed CCD photometry
on August 04/05 and reported that the resulting light curve shows some
small modulations, but clearly nothing related to superhumps
(vsnet-campaign 411). G. Tovmassian and S. Zharikov got the spectrum which
looks very similar to Dwarf Novae in outburst (vsnet-campaign 413).
Time-series photometry is strongly urged to study this object and the
outburst nature.
CI Aql (RA = 18h52m03s.6, Dec = -01d28m38.9s)
The data observed by S. Kiyota can be seen in [vsnet-campaign-data 25-33].
V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)
The striking oscillation is ongoing. A brightening was reported
on July 31 (13.6mag by R. Stubbings) (vsnet-campaign-dn 76).
On August 1st, R. Stubbings reported the object was dimmer than 13.9mag,
and then, showed another brightening on August 2 (vsnet-campaign-dn 82).
S. Walker performed CCD photometry on August 1 and 2, and detected
possible superhumps with their amplitude of 0.1mag (vsnet-campaign-dn 84,
vsnet-campaign 407). A rapid fading from the bright outburst was
reported on August 5 ( <14.8 by R. Stubbings)(vsnet-campaign-dn 96).
Close monitorings and long-run with CCD are encouraged.
BL Lac (RA = 22h02m42s.86, Dec = +42d16'37.6")
The activity becomes mild (vsnet-campaign-blazer 50, 51).
XTE J1118+480 (RA = 11h18m10s.9, Dec = +48d02'12".9)
A dramatic fading from the long outburst was reported by M. Verdenet
(14.3mag on July 31), and then, the light curve of Kyoto team confirmed
the trend (vsnet-campaign-xray 28,29). The decline rate is about 0.07mag/d,
which is faster than previously reported one (vsnet-campaign-xray 29,25,34).
V. Simon sent the long-term light curve to M. Uemura and it can be seen
in [vsnet-image 13] (vsnet-campaign-xray 33). A. Oksanen and M. Moilanen
reported their CCD observation of 14.7mag on August 5, which confirmed
the rapid decline (vsnet-campaign-xray 35).
It is in rapid decline phase. Time-series observation will reveal
the activity during this phase of X-ray nova.
V1494 Aql
The data observed by L. Cook on JD2451711 - 2451755 can be seen in
[vsnet-campaign-nova 73].
V2051 Oph
The object, which had faded on July 24, brightened again on July 31
(vsnet-campaign-dn 77).
*** Future schedule ***
V382 Vel, V1494 Aql, Nova in LMC 2000 campaign
(August 7) (August 21)
S. Starrfield and his collaborators will be obtaining CHANDRA
observations of V382 Vel and V1494 Aql the week beginning August 7, 2000
and they will be obtaining HST/STIS observations of Nova LMC 2000 the
week of August 21, 2000. Ground based observations are encouraged.
Observers those who are interested in this campaign, should contact
with Dr. Starrfield (sumner.starrfield@asu.edu).
[vsnet-campaign-nova 71]
BL Lac campaign (July 17 - August 11)
Massimo Villata, Gino Tosti, and Enrico Massaro organize an
optical campaign on BL Lac contemporaneous with the high-energy
campaign involving X-ray and TeV observatories such as BeppoSAX,
RXTE, STACEE, CAT, HEGRA. Their goal is high-density and
high-precision coverage, possibly in two optical bands (B and R).
Observers interested in participating to this optical campaign are
invited to contact with M. Villata (villata@to.astro.it).
[vsnet-campaign 204]
NY Ser spectroscopic observations at the Calar Alto Observatory
(July 08/09 and 09/10)
D. Nogami noticed their schedule of spectroscopic observations of
NY Ser and wrote: "Because it is quite important for us to know the
state of NY Ser at our observations as accurately as possible, we would
ask observers to make a close monitor of this star for ~1 month from
now (this article was posted on June 29)."
For more information, please see [vsnet-campaign 265], or contact
with D. Nogami (daisaku@uni-sw.gwdg.de).
[vsnet-campaign 265]
V446 Her campaign (throughout this summer)
Boris T. Gaensicke organize a campaign on the post nova V446 Her (V~18).
Their aim is to obtain a *good* contiguous light curve of V446 Her that
covers 2-3 dwarf nova-like outbursts of the system, in order to compare
its outburst characteristics to those of ``normal'' dwarf novae.
They invite those of you equipped with a CCD camera to obtain a couple
of images of V446 Her per night throughout the next three months, say,
until the end of September.
For more information, please see [vsnet-campaign 325] or contact
with Boris T. Gaensicke (boris@uni-sw.gwdg.de).
In [vsnet-campaign 368].....
"The V446 Her campaign from July 7 was started (through the end of
September). But we have received very few observations since then.
Negative observations, for instance, <17.0, are also useful.
We strongly encourage observers to contribute to this project.
Let's clarify the physics of post novae!"
*** General information ***
V2051 Oph
eclipse ephemeris, see [vsnet-campaign-dn 80]
XTE J1118+480
long-term light curves
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-image/msg00013.html
(by V. Simon)
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Xray/xtej1118-camp.html
(by VSNET collaboration team)
(This summary is reproduction free.)
Regards,
Makoto Uemura
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VSNET Home Page: http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/
=============================================================================
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