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[vsnet-campaign-news 96] News from VSNET 67
*** News from VSNET ***
Long awaited superhumps have finally appeared, however their
profiles are quite variable with time.
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 August 4, 2001, as VSNET campaign circulation 1063
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V1329 Cyg (RA = 20h51m01s.27, Dec = +35d34'53".2)
The symbiotic nova V1329 Cyg is apparently undergoing an
outburst (~12.5mag) as reported during the last week
(vsnet-campaign 1065).
OY Car (RA = 10h06m22s.46, Dec = -70d14'04".4)
As reported by P. Williams on August 4, the eclipsing SU UMa
type dwarf nova OY Car is undergoing an outburst of 11.2mag
(vsnet-campaign 1067). It was faded to 12.2mag on the next night
(vsnet-campaign-dn 1113), and the gradual fading is still continues
(vsnet-campaign-dn 1148).
HadV98 (RA = 17h23m14s.5, Dec = -22d52'05")
K. Haseda reported the discovery of a new variable star (HadV98).
The variable had been almost constant for years at 10.6-10.7mag,
and suddenly faded to <12.8mag since around May 2001. This star
may be a new R CrB star or a long-period eclipsing binary
(or something else?). The lack of IRAS detection may be against
the R CrB-type interpretation, but has been a result of source
confusion (vsnet-campaign 1089). K. Kanatsu confirmed the fading
of this new variable star (vsnet-campaign 1090).
SN 2001dm (RA = 01h55m40s.55, Dec = -29d55'20".7)
Accoring to IAUC 7679, the discovery of a new SN 2001dm was made
on Aug 7.5 when the object was mag about 15.4C. The position is
about 7" due west of the nucleus of the spiral galaxy NGC 749.
This galaxy has bright bulge and rather faint arm structure, and
the SN superimposed on the bulge. The expected maximum of typical
SN Ia on this galaxy is around 15.5 mag (vsnet-campaign-sn 214).
DH Aql (RA = 19h26m12s.05, Dec = -10d15'21".4)
As reported by M. Simonsen on August 7, DH Aql experienced an
outburst of 13.5mag (vsnet-campaign-dn 1145). The outburst was
ongoing until August 8, and then, possibly faded
(vsnet-campaign-dn 1149, 1162).
V Sge (RA = 20h20m14s.75, Dec = +21d06'09".0)
As reported during the last week, V Sge is now bright at about
10.5mag (vsnet-campaign-nl 25).
RZ Sge (RA = 20h03m18s.49, Dec = +17d02'52".6)
RZ Sge is in a possible superoutburst at around 13mag
(vsnet-campaign-dn 1182, 1191).
V1008 Her (RA = 18h05m46s.31, Dec = +31d40'18".1)
As reported by M. Simonsen on August 12, V1008 Her is now
in outburst at 14mag (vsnet-campaign-dn 1190).
(continuous targets)
WZ Sge (RA = 20h07m36s.53, Dec = +17d42'15".3)
The historical outburst is still ongoing, and the current magnitude
is about 10.4mag (vsnet-campaign-dn 1104, 1114, 1140, 1160, 1183).
Long waited superhumps have finally appeared: The secondary humps
(preceding to the main peak of the early superhumps) became stronger
on August 4 (vsnet-campaign 1066, vsnet-campaign-dn 1106, 1107).
A longer period of humps were reported, which indicated genuine
superhumps were evolving (vsnet-campaign 1068, vsnet-campaign-dn 1108,
vsnet-campaign 1069). L. Cook reported that they found flickerings
were greatest in U-band (vsnet-campaign-dn 1109). On August 5,
the evolution of the superhumps were confirmed, and furthermore,
their evolution is quite rapid (vsnet-campaign-dn 1112, vsnet-campaign
1070, vsnet-campaign 1072, vsnet-campaign 1073, vsnet-campaign-dn 1115,
vsnet-campaign-dn 1117, vsnet-campaign 1084, vsnet-campaign 1085).
T. Kato and G. Masi obtained an unexpectedly large superhump period
with the data obtained on August 5 (vsnet-campaign 1074,
vsnet-campaign-dn 1111, vsnet-campaign-dn 1116, vsnet-campaign 1076,
vsnet-campaign-dn 1123), however, shorter periods were reported after
August 6 (vsnet-campaign 1077, 1078, 1079, 1080, 1081), and then,
T. Kato found that there was an interchange of maxima from early
superhumps to true superhumps around Aug. 5.8 UT. This affected the
period analysis on Aug. 5, and he determined the period of true
superhumps as 0.057157 +/- 0.000077 d (vsnet-campaign 1082). Both
periods are significantly different (vsnet-campaign 1086,
vsnet-campaign 1088).
Once the superhumps were evolved, however the profile has shown
a rapid variation: G. Masi commented that new secondary humps
(following to the main peak of genuine superhumps) have appeared
since August 6 (vsnet-campaign-dn 1122, 1123, 1120, 1121).
T. Kato presented an O-C diagram of early and genuine superhumps
in the VSNET web page (vsnet-campaign 1083, vsnet-campaign 1087).
On August 7, G. Masi reported that eclipses were re-occurring in
excellent agreement with the ephemeris (vsnet-campaign-dn 1129, 1127).
On August 8 and 9, the general fading has almost stopped and the
beat phenomenon of ~4 d modulation seems to be observed
(vsnet-campaign-dn 1133, 1134, 1139, 1151, 1188). The secondary humps
were further evolved (vsnet-campaign-dn 1141, 1142, 1146, 1147, 1150,
1151, 1152, 1153, 1154). On August 10, the secondary humps became
further stronger and almost equivalent as those on August 9
(vsnet-campaign-dn 1156, 1157, 1158, 1163, 1177). The eclipses were
weak at that time (vsnet-campaign-dn 1155, 1167). T. Kato commented
that it may be possible that the unique profile was caused by the
somwhow enhanced early superhumps at this stage (vsnet-campaign-dn 1163).
On August 11, two humps gradually merged into single-peaked superhumps
(vsnet-campaign-dn 1169, 1179, 1192, 1193). The eclipses were again
appeared since August 10 and became deeper on August 11
(vsnet-campaign-dn 1170, 1181, 1184). The depth of the eclipses were
much variable with time (vsnet-campaign-dn 1185, 1186).
The superhump period was revised and the most recent value is
0.057194 +/- 0.000015 d (vsnet-campaign 1091, 1092, 1093,
vsnet-campaign-dn 1143, 1188).
Time-series observations by S. Kiyota is available in
[vsnet-campaign-data 72]. M. Richmond performed a number of
time-series observations and provided the data on his web (see below,
vsnet-campaign-dn 1119, vsnet-campaign-dn 1128, 1135, 1137, 1165, 1166,
1180, 1187). He further reported that there are some sharp dips in
the B-band right curve, which are also observed by G. Masi and the other
observations (vsnet-campaign-dn 1138, 1136, 1135).
delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
S. Otero reported that delta Sco reached a new peak of V=1.74.
The object may show fading since this week (vsnet-campaign-be 138).
KL Dra (RA = 19h24m38s.14, Dec = +59d41'47".1)
G. Masi reported that it was at about Rc=17.5mag on August 11,
which tells the outburst was still not faded (vsnet-campaign-dn 1172).
IX Dra (RA = 18h12m32s.2, Dec = +67d04'41")
A new outburst of 15.4mag was detected by G. Poyner on August 9
(vsnet-campaign-dn 1161).
IP Peg (RA = 23h23m08s.7, Dec = +18d24'59".1)
The outburst was faded (vsnet-campaign-dn 1105).
V2274 Cyg (RA = 20h07m17s.94, Dec = +36d04'37".2)
R. Novak reported that this nova showed sinusoidal short-term
modulations (vsnet-campaign-nova 426, vsnet-campaign 1064).
He performed period analysis and reported about 0.30d period
with 0.1mag amplitude (vsnet-campaign-nova 427). The current
magnitude is around 13.8mag (vsnet-campaign-nova 428, 429).
BL Lac (RA = 22h02m42.86s, Dec = +42d16'37.6")
The object remains faint state (vsnet-campaign-blazar 220).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
The strong activity is still seen around 14mag (vsnet-campaign-dn
1125).
V1548 Aql (RA = 19h07m28s.42, Dec = +11d44'45".8)
The object was brightening to about 13.5mag during the last
week (vsnet-campaign-nova 430).
AM Her (RA = 18h16m13s.4, Dec = +49d52'03".1)
The object is still very active around 13mag (vsnet-campaign 1095).
*** Future schedule ***
AM Her and VY Scl stars campaign with the Keck I telescope
from August 12-14
F. Rinwald wrote in [vsnet-campaign 1059]:
"Many cataclysmic variables, especially AM Her and VY Scl stars, have
erratic and poorly understood low states. We have an observing run
scheduled on the Keck I telescope from August 12-14, to find out why. It
has long been suspected that these low states may be due to starspots on
the mass-losing star that form or move over L1 and choke off the flow.
This idea is not without problems, however, but then that's why we want to
get our spectra."
They call for photometric monitorings and listed targets in
[vsnet-campaign 1059] and [vsnet-campaign-nl 23].
Further information: [vsnet-campaign-nl 24]
WZ Sge campaign
D. Steeghs wrote:
"Several of us are organizing a campaign on the current outburst
of WZ Sge, using a large variety of ground based facilities as well as
space observatories. A web-page has been setup listing the scheduled
observations so far which we intend to keep up to date at:
http://vsnet.astro.soton.ac.uk/~ds/wzsge.html
"
For more information, see [vsnet-campaign 1039]
V446 Her campaign until September
conducted by Matthias Schreiber, Boris Gaensicke, and Daisaku Nogami
For more detailed information, see [vsnet-campaign-dn 918],
[vsnet-campaign-nova 349], or [vsnet-campaign 983]
Two Years of Science with Chandra *
* This meeting will also be the 12th Annual Maryland Astrophysics
Conference
September 5-7, 2001
For more information, see [vsnet-campaign-xray 66]
*** General information ***
WZ Sge
light curves presented by L. Cook:
http://vsnet.geocities.com/lcoo/wzsge4c.htm
[vsnet-campaign-dn 1109]
VSNET page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/wzsge01.html
[vsnet-campaign-dn 1110, 1118, 1124,
1131, 1132, 1144, 1159, 1171,
1189, vsnet-campaign 1075]
Nightly averaged magnitude by VSNET team, see [vsnet-campaign-dn 1164]
light curves presented by G. Masi:
http://vsnet.eurolink.it/comets/wzsge.htm
[vsnet-campaign 1071,
vsnet-campaign-dn 1123, 1130, 1141,
1167, 1173, 1179]
Time-series data by M. Richmond:
http://spiff.rit.edu/richmond/ritobs/aug05_2001/aug05_2001.html
[vsnet-campaign-dn 1126,1135]
http://spiff.rit.edu/richmond/ritobs/aug06_2001/wzsge_aug06ut.dat
http://spiff.rit.edu/richmond/ritobs/aug06_2001/wzsge_aug06ut.png
[vsnet-campaign-dn 1128]
http://spiff.rit.edu/richmond/ritobs/aug06_2001/aug06_2001.html
http://spiff.rit.edu/richmond/ritobs/aug08_2001/aug08_2001.html
[vsnet-campaign-dn 1135]
http://spiff.rit.edu/richmond/ritobs/aug11_2001/aug11_2001.html
[vsnet-campaign-dn 1176]
Web page for WZ Sge by M. Richmond:
http://spiff.rit.edu/richmond/ritobs/wzsge.html
[vsnet-campaign-dn 1176]
Light curve on B. Martin's page:
http://vsnet.kingsu.ab.ca/%7Ebrian/astro/cba_alta/data_archive/wzsge/wzsge.html
[vsnet-campaign-dn 1174]
T. Vanmunster's web page for WZ Sge:
http://vsnet.lunarpages.com/cbabelgium
[vsnet-campaign-dn 1177, 1192]
OY Car
eclipse ephemeris, see [vsnet-campaign 1067].
V2274 Cyg
light curves presented by R. Novak:
http://ada.astronomy.cz
[vsnet-campaign-nova 427]
HadV98
CCD image by T. Scarmato, see [vsnet-image 58]
[vsnet-campaign 1094]
Salvo Massaro's Software for supernovae research
see, [vsnet-campaign-sn 213].
(This summary can be cited.)
Regards,
Makoto Uemura
vsnet-adm@kusastro.kyoto-u.ac.jp
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page