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[vsnet-campaign-news 188] News from VSNET
*** News from VSNET ***
BZ UMa experienced a rare outburst. An outburst of the eclipsing
dwarf nova, IY UMa was detected.
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 December 23, 2002, as VSNET campaign
circulation 1355
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
IY UMa (RA = 10h43m56s.87, Dec = +58d07'32".5)
According to T. Kinnunen, the eclipsing SU UMa-type dwarf nova IY
UMa experienced an outburst of 14.2mag on December 21
(vsnet-campaign-dn 3165).
ASAS 000155-6707.7 (RA = 00h01m54s.2, Dec = -67d07'49")
P. Wils reported in [vsnet-id 720]: The variable ASAS
000155-6707.7 in the third list of ASAS variables
(http://archive.princeton.edu/~asas/) may be identified with the
novalike variable 1RXSJ000154.2-670749 = EC 23593-6724 from the list
of Downes et.al. It is classified as MISC with a period of 228 days
in the ASAS catalogue. Two outbursts to about mag 12.4 were
observed near JD 2451890 and 2452120, so it is probably a new dwarf
nova (vsnet-campaign-dn 3146).
SN 2002jy (RA = 01h21m16s.27, Dec = +40d29'55".3)
NGC 477, a host galaxy of SN 2002jy is a open spiral galaxy, which
makes a pair with MCG +07-03-031. The SN is located on the
outermost northwestern arm. The expected maximum for typical SNe Ia
is mag about 16.3 (vsnet-campaign-sn 521).
BZ UMa (RA = 08h53m44s.3, Dec = +57d48'40".1)
As reported by E. Muyllaert, the unusual dwarf nova BZ UMa
experienced its relatively rare outburst (the last confirmed one in
2001 May). This object is reported to have a short orbital period
(below the period gap), which may imply the SU UMa-type nature.
However, no definite superoutbursts have been observed. The object
may be related to another below-the-gap object HT Cam, which is
confirmed to be an intermediate polar (IP). Although no definite
pulse period has been established, BZ UMa has been reported to show
quasi-periodic oscillations (QPOs) in outburst, which may related to
optical pulses seen in HT Cam (vsnet-campaign-dn 3151, 3152).
T. Vanmunster performed time-series photometry for 5.05 hr on
December 19/20, and reported that the light curve was rather flat
(vsnet-campaign-dn 3160, 3161). The object may have started fading
on December 20 (vsnet-campaign-dn 3175).
RX J1155.4-5641 (RA = 11h55m27s.0, Dec = -56d41'53")
As reported by R. Stubbings on December 19, the SU UMa-type dwarf
nova RX J1155.4-5641 experienced an outburst (11.9mag)
(vsnet-campaign-dn 3157). The probable superoutburst is still
continues (vsnet-campaign-dn 3173).
V383 Vel (RA = 10h21m41s.7, Dec = -49d49'24".33)
R. Stubbings reported the 12.6mag outburst of V383 Vel on December
21 (vsnet-campaign-dn 3169).
BU Tau (RA = 03h49m11s.19, Dec = +24d08'12".4)
The object has been reported to be brighter at about 5.0mag
(vsnet-campaign-be 202).
omega CMa (RA = 07h14m48s.70, Dec = -26d46'22".1)
The object is gradually brightening (vsnet-campaign-be 203).
(continuous targets)
CU Vel (RA = 08h58m32s.87, Dec = -41d47'50".8)
The superhump period was dramatically changed during the early
superoutburst phase. After this phase, the object has shown a firm
superhump period of 0.08085(3) d (vsnet-campaign-dn 3137). On
December 16 and 17, the light curves showed broader superhumps with
slightly longer superhump period. The period increase of superhumps
is usually a characteristic of short Psh systems related to WZ
Sge-type stars, and is quite unusual for a long Psh system
(vsnet-campaign-dn 3143, 3153). T. Kato reported on December 20
that the superhump period may then turned to decrease
(vsnet-campaign-dn 3158, 3164, 3167). The amplitude of superhumps
started decreasing, and the signature of secondary superhumps became
stronger (vsnet-campaign-dn 3167, 3177). The superoutburst continues
(vsnet-campaign-dn 3139, 3145, 3149, 3155, 3172).
ST Cha (RA = 10h47m31s.3, Dec = -79d27'17")
A standstill from the early December was terminated by a sudden
fading on December 10, and then, it was reported to brighten again
on December 21 (vsnet-campaign-dn 3174).
V844 Her (RA = 16h25m01s.69, Dec = +39d09'25".9)
T. Kinnunen reported an outburst (12.5mag) on December 21. The
outburst interval is reported to be unusually short. The last
outburst (2002 Oct. 23-25) was a normal one. P. Schmeer commented
that the present outburst looks more like a supermaximum
(vsnet-campaign-dn 3176). T. Kato reported that, if the
superoutburst nature of the present outburst is confirmed, V844 Her
belongs to rather unusual SU UMa-type dwarf novae having clearly
different maximum magnitudes (cf. SW UMa, BC UMa) (vsnet-campaign-dn
3178).
BB Vel (RA = 08h36m49s, Dec = -47d22'39")
The time-series data obtained by T. Richards did not show apparent
superhumps, suggesting that BB Vel is a long period system rather
than an SU UMa star (vsnet-campaign-dn 3163, 3166).
U Gem (RA = 07h55m05s.55, Dec = +22d00'09".2)
An outburst was reported by T. Kinnunen and R. Stubbings on
December 21. The outburst interval may be relatively long
(vsnet-campaign-dn 3168, 3171).
eta Gem (RA = 06h14m52s.87, Dec = +22d30'24".5)
The object is still in the faint state, or the possible eclipse
(vsnet-campaign-ecl 53).
BL Lac (RA = 22h02m42s.86, Dec = +42d16'37".6)
The slightly active state continues (vsnet-campaign-blazar 291).
TU Men (RA = 04h41m38s.10, Dec = -76d36'09".7)
An outburst to 12.6mag was reported on December 17 by R. Stubbings
(vsnet-campaign-dn 3144). The object was reported to further
brightened to 12.0-11.9mag, which indicates that the current
outburst is a superoutburst (vsnet-campaign-dn 3148). In the light
curve obtained by P. Nelson, the object showed ~0.04 mag variation,
which may be either a general fading trend or a part of superhump
variation (vsnet-campaign-dn 3154). His next run showed no rapid
fading, suggesting that the outburst is a long outburst
(vsnet-campaign-dn 3162). The long outburst is ongoing
(vsnet-campaign-dn 3156, 3170).
Z Cha (RA = 08h07m16s.29, Dec = -76d32'20".9)
The object has faded from the superoutburst on December 18
(vsnet-campaign-dn 3140, 3150).
MisV1147 (RA = 22h54m03s.78, Dec = +58d54'02".1)
D. West reported that the object shows weak H_alpha emission,
which is consistent with the idea that this object is a YSO
(vsnet-campaign-unknown 163, 164).
NSV 10934 (RA = 18h40m52s.26, Dec = -83d43'10".24)
T. Kato reported that the next outburst of NSV 10934 is expected
to occur within a short time from the past history of its outbursts.
Since the evolution of outbursts has been always very quick, timely
observations (and alerts) are very keenly needed. The object is
possibly an analogous object to HT Cam, which displayed multiple
periodic oscillations during the outburst last year
(vsnet-campaign-dn 3141).
*** Future schedule ***
WEBT campaign on Mkn 421
M. Villata announced possible WEBT campaign on Mkn 421, in
December 2002 and February-March 2003, to be carried out during
multifrequency campaigns.
The relevant information on the MW campaign of December 2-16 is at
the VERITAS site <http://veritas.sao.arizona.edu> .
[vsnet-campaign-blazar 287]
[vsnet-campaign-blazar 288]
SUPERNOVAE (10 YEARS OF SN1993J)
22-26 April 2003, Valencia, Spain
Web site: http://vsnet.uv.es/2003supernovae/
[vsnet-campaign-sn 342]
[vsnet-campaign-sn 452]
[vsnet-campaign-sn 512]
*** General information ***
CU Vel
VSNET CU Vel page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/cuvel0212.html
[vsnet-campaign-dn 3138]
Combined light curve on Dec. 17:
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/DNe/CU_Vel/sh17.gif
[vsnet-campaign-dn 3147]
NSV10934
Chart presented by M. Simonsen:
http://joevp.20m.com/cgi-bin/i/charts/provisional/NSV_10934_C_northup.jpg
[vsnet-campaign-dn 3142]
RX J1155.4-5641
Chart presented by M. Simonsen:
http://joevp.20m.com/cgi-bin/i/charts/provisional/RXJ1155.4-564_C_northup.jpg
[vsnet-campaign-dn 3159]
IY UMa
Eclipse ephemeris, see [vsnet-campaign-dn 3165]
delta Sco
IBVS paper by Gandet, T., Otero, S., Fraser, B., and West, J. D.:
http://vsnet.konkoly.hu/cgi-bin/IBVS?5352
[vsnet-campaign-be 204]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page