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*** News from VSNET ***
RX Vol and OU Vir turned out to be SU UMa-type dwarf novae.
They are now in superoutburst.
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 May 6, 2003, as VSNET campaign
circulation 1388
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V2527 Oph (RA = 17h22m04s.3, Dec = -19d49'08")
As reported in [vsnet-outburst 5472] on May 2, the (still poorly
known) SU UMa-type dwarf nova V2527 Oph = 1E1719.1-1946 = 1RXS
J172204.5-194913 experienced a very bright outburst (13.8mag).
The reported magnitude surpasses the past record. The object is an
X-ray source selected from Einstein survey, and later spectroscopic
observation confirmed its CV nature. This spectrum resembles that
of a short-period dwarf nova (vsnet-campaign-dn 3604). The outburst
was confirmed on May 3 (vsnet-campaign-dn 3605). No obvious
modulation was visible from the data taken by B. Monard on May 3
(vsnet-campaign-dn 3609). In the light curve taken on May 4-5, the
object was rather monotonously fading. The mean fading rate was
0.70 mag/d, which is not characteristic of those of SU UMa-type
normal outbursts (vsnet-campaign-dn 3618). The object is fading
(vsnet-campaign-dn 3608, 3619).
RX Vol (RA = 08h39m32s.30, Dec = -66d17'39".2)
As reported by R. Stubbings on May 4, RX Vol experienced an
outburst (14.7mag). RX Vol is a candidate of an SU UMa type dwarf
nova (vsnet-campaign-dn 3610, 3611, 3612, vsnet-campaign 1385,
1386, vsnet-campaign-dn 3613). P. Nelson provided a 2.7-hour
time-series photometry. The data showed 0.1 mag modulations, which
are probably emerging superhumps. The period is about 0.0613(2) d,
suggesting that RX Vol belongs to a short-period SU UMa-type dwarf
nova (vsnet-campaign-dn 3614, 3621). The object further brightened
on May 5 (vsnet-campaign-dn 3617).
OU Vir (RA = 14h35m00s.14, Dec = -00d46'07".0)
As reported by M. Simonsen and R. Stubbings, the eclipsing SU
UMa-type dwarf nova OU Vir = LBQS 1432-0033 is reported to be in
outburst (15.0mag). OU Vir is reported to have superhump and
orbital periods of 0.078 and 0.073 d, but the exact periods have not
yet been determined to a higher precision (vsnet-campaign-dn 3615).
D. Nogami detected a fully developed superhump with an amplitude of
0.35 mag and an 0.45-mag eclipse lasting ~13 min. Thus, the current
outburst is evidently a superoutburst (vsnet-campaign-dn 3620,
vsnet-campaign 1387).
SN 2003dw (RA = 16h45m51s.10, Dec = +59d37'38".0)
SN 2003dw is hosted by MCG +10-24-51 = UGC 10548, a barred-spiral
galaxy. The discovery magnitude is close to the expected maximum
for typical SN Ia (vsnet-campaign-sn 613).
LMCV4263 (RA = 05h45m03s, Dec = -64d24'.4)
It is fading now, as reported by P. Williams (vsnet-campaign-rcb 141).
SN 2003ec (RA = 15h46m16s.67, Dec = +02d24'48".7)
SN 2003ec is hosted by NGC 5990, a spiral galaxy. The expected
maximum for typical SN Ia is mag about 15.6 (vsnet-campaign-sn 615).
EI UMa (RA = 08h38m22s.1, Dec = +48d38'01")
EI UMa = PG 0834+488 was reported to become very faint, but
follow-up observations did not confirm the faint state
(vsnet-campaign-nl 114, 115).
IGR J17597-2201 (RA = 17h59m.7, Dec = -22d01')
B. Monard performed unfiltered CCD observations of the field of
the new X-ray transient, IGR J17597-2201. No obvious candidate for
the optical counterpart can be suggested up to a limiting magnitude
of 19.5CR (vsnet-campaign-xray 239).
WX Cen (RA = 13h12m52s.5, Dec = -63d23'45"
According to the ASAS-3 survey data, the V Sge/SSS type WX Cen may
be brightening (currently around V=13.1) (vsnet-campaign-nl 111).
B. Monard confirmed the bright state (vsnet-campaign-nl 112, 113).
DY Cru (RA = 12h47m24s.7, Dec = -59d41'41")
According to the ASAS-3 survey data, the R CrB-like star DY Cru
may be steadily fading (currently around V=8.8) (vsnet-campaign-rcb
129). F. Farrell and S. Otero reported that it is currently not
unusual magnitudes. S. Otero analized his data combined with the
ASAS-3 data, and proposes that the object is an L-type star
(vsnet-campaign-rcb 136, 137, 138).
UX Ant (RA = 10h57m09s.03, Dec = -37d23'55".8)
According to the ASAS-3 survey data, the R CrB star UX Ant is
slowly brightening (currently around V=12.6) (vsnet-campaign-rcb 130).
S Dor (RA = 05h18m14s.4, Dec = -69d15'01")
According to the ASAS-3 survey data, the S Dor-type prototype star
S Dor is steadily fading (currently at V=9.1) (vsnet-campaign-sdor 31).
V2905 Sgr (RA = 18h17m20s.5, Dec = -28d09'51")
According to the ASAS-3 survey data, the Z And-type star V2905 Sgr
is rather rapidly fading (currently at V=12.5)
(vsnet-campaign-symbio 53, 60, 61, 63).
V3804 Sgr (RA = 18h21m28s.6, Dec = -31d32'03")
According to the ASAS-3 survey data, the Z And-type star V3804 Sgr
is brightening (currently at V=12.5) (vsnet-campaign-symbio 54, 60).
V3795 Sgr (RA = 18h13m24s.0, Dec = -25d46'56")
This R CrB-star is undergoing a dramatic fading, as reported by
R. Stubbings on April 29, and noticed by T. Kato. This star has not
long been observed in faint state (vsnet-campaign-rcb 131, 140).
P. Williams reported that the most recent declines of V3795 Sgr
commenced in 1993 March when it faded to near magnitude 13 and in
1992 February when it faded to fainter than 14 (vsnet-campaign-rcb 142).
FN Sgr (RA = 18h53m54s.79, Dec = -18d59'40".8)
According to the ASAS-3 survey data, the Z And-type star FN Sgr is
rapidly brightening (currently at V=11.8). It is possibly
undergoing a new outburst, or an egress from an eclipse
(vsnet-campaign-symbio 55, 60).
V919 Sgr (RA = 19h03m45s.5, Dec = -16d59'55")
According to the ASAS-3 survey data, the Z And-type star V919 Sgr
may be slowly fading (currently at V=13.1) (vsnet-campaign-symbio
56, 60).
V4368 Sgr (RA = 18h54m40s.5, Dec = -19d41'56")
According to the ASAS-3 survey data, the NC?-type star V4368 Sgr
is still slowly fading (currently at V=10.9) (vsnet-campaign-nova 1236).
ES Aql (RA = 19h32m21s.58, Dec = -00d11'31".2)
According to the ASAS-3 survey data, the R CrB-type star ES Aql is
slowly recovering (currently at V=13.2). The trend is in good
agreement with the VSNET observations (vsnet-campaign-rcb 132).
SY Cir (RA = 14h03m44.9s, Dec = -69d37'31")
The data of the ASAS-3 survey show that the object is likely a
dwarf nova with a period of 10-20 d, as previously proposed. The
object looks similar to CN Ori or other short-period SS Cyg stars.
However, the VSNET reports have not yet detected any outburst.
Since most of the recorded outburst by ASAS-3 reach V=11.5, they
must have been well above visual detection limits. The star may
have been mislabeled on some chart for visual observation
(vsnet-campaign-dn 3603).
V CrA (RA = 18h47m32s.3, Dec = -38d09'32")
According to the ASAS-3 survey data, the R CrB-type star V CrA
seems to be slightly faint (about V=10.1) and possibly slowly fading
(vsnet-campaign-rcb 133).
WX CrA (RA = 18h08m50s.5, Dec = -37d19'43")
According to the ASAS-3 survey data, the R CrB-type star WX CrA is
fading (currently at V=12.0). The fading continues throughout this
observing season (about 1 mag by 30 day) (vsnet-campaign-rcb 134).
BI Cru (RA = 12h23m26s.0, Dec = -62d38'16")
According to the ASAS-3 survey data, the Z And-type star BI Cru
faded (reaching about V=13.2) and now recovering. The trend is in
agreement with the data reported to VSNET. The light curve suggests
an eclipse (vsnet-campaign-rcb 135, vsnet-campaign-symbio 57).
XX Oph (RA = 17h43m56s.5, Dec = -06d16'09")
According to the ASAS-3 survey data, the peculiar star XX Oph is
steadily fading (currently about V=9.2). This trend seems to be
ongoing with a time scale of 2-3 years (vsnet-campaign-symbio 58).
HK Sco (RA = 16h54m41s.2, Dec = -30d23'06")
According to the ASAS-3 survey data, the Z And-type star HK Sco
seems to be in outburst (currently at V=12.9) (vsnet-campaign-symbio 59).
V1860 Sgr (RA = 18h21m28s.5, Dec = -24d45'09")
According to the ASAS-3 data, V1860 Sgr shows relatively regular
variations (amplitude 0.3 mag) with a period of 40-50 d. This
periodicity is characteristic to R CrB-type variations at maximum.
Although spectroscopic observation is against the classification as
an R CrB star, this star probably needs more detailed examination
(vsnet-campaign-rcb 139).
IV Vir (RA = 14h16m34s.3, Dec = -21d45'49")
According to the ASAS-3 data, IV Vir (possible Z And star?) shows
rather marked regular variation with a period around 140 d
(amplitude 0.1-0.2 mag). There have been no major outburst-like
brightening. The variation is consistent with the GCVS description
(vsnet-campaign-symbio 62).
HadV14 (RA = 15h10m24s.39, Dec = -40d54'28".3)
According to the ASAS-3 data, HadV14 is a clear Mira star. This
star is also known as the emission-line star Wray 1292. The maxima
reached about V=11.2 (vsnet-campaign-unknown 199).
(continuous targets)
V4745 Sgr = Nova Sgr 2003
(RA = 18h40m02s.54, Dec = -33d26'55".1)
The Nova Sgr 2003 has been given the permanent GCVS designation of
V4745 Sgr (vsnet-campaign-nova 1222). Pre-discovery observations by
H. Nishimura showed that it was already bright at 8.5p mag on
April 12 (vsnet-campaign-nova 1232). Furthermore, the ASAS survey
has revealed that the nova was brightening on April 10
(vsnet-campaign-nova 1234). The reported observations show some
hints of oscillations around 9mag (vsnet-campaign-nova 1223, 1224,
1225, 1226, 1227, 1228, 1229, 1230, 1231, 1233, 1240).
SN 2003ds (RA = 10h18m58s.35, Dec = +46d27'15".5)
The host galaxy of SN 2003ds is not NGC 3191, but MCG +08-19-17 =
KUG 1015+467, a compact galaxy with a UV excess. It is located
about 1' west of NGC 3191 (vsnet-campaign-sn 614).
SN 2003dv = POSSIBLE SUPERNOVA IN UGC 9638
(RA = 14h58m04s.92, Dec = +58d52'49".9)
IAUC 8124 informed that the INT spectrum of this object taken on
Apr. 26.11 UT revealed that it was of type IIn SN, about a week
after explosion. The discovery magnitude of SN 2003dv is near to
that of typical gravitational-collapsed event (M ~ 17)
(vsnet-campaign-sn 613).
V551 Sgr (RA = 18h00m56s.46, Dec = -34d35'45".6)
The object further faded (vsnet-campaign-dn 3602).
V2051 Oph (RA = 17h08m19.1s, Dec = -25d48m31.1s)
During the rapid fading phase from the superoutburst, the
superhump profile on April 28 was double-humped, probably a
combination of orbital humps and late-stage superhumps
(vsnet-campaign-v2051oph 43). A preliminary analysis of the data
suggests that the superhump-type signal still persists as of
Apr. 29, although the object has significantly faded
(vsnet-campaign-v2051oph 44). After that, the fading has apparently
stopped, and the light curve was dominated with double humps
(vsnet-campaign-v2051oph 45). In light curves on April 30, a
post-eclipse hump became more prominent, indicating that some sort
of late superhumps may be still persisting (vsnet-campaign-v2051oph 46).
delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
The object is now getting brighter (vsnet-campaign-be 231, 232,
233, 234, 235, 236).
V348 Sgr (RA = 18h40m19s.94, Dec = -22d54'29".1)
The object faded again on May 4 (vsnet-campaign-rcb 143).
XTE J1550-564 (RA= 15h50m58s.68, Dec = -56d28'34".8)
The object is rapidly fading (vsnet-campaign-xray 240).
*** Future schedule ***
IM Nor Campaign
by I. Hachisu (University of Tokyo) and the VSNET team
For more information, see [vsnet-campaign-nova 1241]
GRB Mini-Symposium in JENAM2003
For more information, http://vsnet.konkoly.hu/jenam03/
[vsnet-campaign-grb 31]
IAU JD17 "ATOMIC DATA FOR X-RAY ASTRONOMY"
ON JULY 22-23, 2003 at the XXVth IAU GENERAL ASSEMBLY
SYDNEY, AUSTRALIA, JULY 13-26, 2003
for more information:
http://vsnet.astronomy.ohio-state.edu/~pradhan/Iau/iau.html
[vsnet-campaign-xray 227]
"X-ray and Radio Emission of Young Stars"
July 28 - 29, 2003, Rikkyo University, Tokyo, Japan
for more information , please contact to kitamoto@rikkyo.ne.jp
[vsnet-campaign-xray 218]
Conference: THE INTERPLAY AMONG BLACK HOLES, STARS AND ISM IN
GALACTIC NUCLEI
in Gramado, south of Brasil, March 1-5, 2004
for more information, please contact to BHSIGN@if.ufrgs.br
[vsnet-campaign-agn 3]
eta Car: The next "shell event"/X-ray eclipse
M. Corcoran reported the event will occur this summer.
Coordinated ground-based observations of eta car along with the
X-ray observations would be really important.
For more information:
Latest X-ray light curve:
http://lheawww.gsfc.nasa.gov/users/corcoran/eta_car/etacar_rxte_lightcurve/
[vsnet-campaign-sdor 23, 24,
25, 26, 28, 29]
[vsnet-campaign-xray 172]
Light curve provided by S. Otero:
http://ar.geocities.com/varsao/Curva_Eta_Carinae.htm
[vsnet-campaign-sdor 22]
The 2003 Gamma Ray Burst conference
Hosted by Los Alamos,
in Santa Fe, New Mexico (USA), between September 8 and 12, 2003
http://grb2003.lanl.gov/
[vsnet-campaign-grb 13]
*** General information ***
V4745 Sgr
Image taken by S. Kiyota:
http://vsnet.milky.ne.jp/~meineko/CCD/nvSgr2003.jpg
Spectrum taken by S. Kiyota:
http://vsnet.milky.ne.jp/~meineko/CCD/v4745sgrspe.jpg
[vsnet-campaign-nova 1228]
Spectrum taken by D. West:
http://members.aol.com/dwest61506/page71.html
[vsnet-campaign-nova 1235]
Sequence provided by M. Morel, see [vsnet-campaign-nova 1237]
Spectrum taken by C. Buil:
http://astrosurf.com/buil/us/v4745sgr/v4745sgr.htm
http://astrosurf.com/buil/us/nsgr3/nsgr3.htm
[vsnet-campaign-nova 1238, 1239]
V2540 Oph
Spectrum taken by C. Buil:
http://astrosurf.com/buil/us/noph/noph.htm
[vsnet-campaign-nova 1239]
V838 Mon
Spectrum taken by C. Buil:
http://astrosurf.com/buil/us/nmon/nmon.htm
[vsnet-campaign-nova 1239]
V551 Sgr
VSNET page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v551sgr.html
[vsnet-campaign-dn 3601]
RX Vol
VSNET page:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/rxvol.html
[vsnet-campaign-dn 3616]
NMO Campaign, see [vsnet-campaign-mira 59]
ASAS project, see [vsnet-campaign-dn 3606, 3607]
(This summary can be cited.)
Regards,
Makoto Uemura
Return to the Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
