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[vsnet-campaign-news 100] News from VSNET 71
*** News from VSNET ***
A nova was discovered again in Sagittarius. A new X-ray transient
(black hole binary?) was discovered. WZ Sge is still active.
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 September 10, 2001, as VSNET campaign circulation
1162
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SN 2001ed (RA = 01h51m51s.08, Dec = +06d17'27".4)
M. Migliardi discovered a supernova, SN 2001ed on September
2.96 and 3.01 when the object was 14.9mag. The position is about
9" east and 20" south of the nucleus of the face-on spiral galaxy
NGC 706. The reported magnitude is far brighter than the expected
maximum of SN Ia from the recession velocity of NGC 706. It seems
the same case as SN 2001cj, who has a great concern of its distance
(vsnet-campaign-sn 234, 235). Prediscovery observations informed
in IAUC 7704 shows that the object can be a type II SN in its
plateau phase, or other type SN some days (or a week) after maximum
(vsnet-campaign-sn 236).
Nova Sgr 2001 No. 3 = V4740 Sgr
(RA = 18h11m45s.82, Dec = -30d30'49".9)
IAUC 7706 informed that Nova Sgr 2001 No.3 was independently
discovered by A. J. S. Pereira (7.0mag on September 5) and W. Liller
(10.0mag on September 3)(vsnet-campaign-nova 517). Confirmations
were reported to VSNET by J. Carvajal (vsnet-campaign-nova 516).
The object reached 6.5mag around September 6 (vsnet-campaign-nova
518, 519, 522, 523, 526, 527, 530). Early multi-color observations
on September 6 were reported by A. Price (vsnet-campaign-nova 520).
H. Yamaoka reported that no object brighter than the limit
(rmag about 20) exists within 4" around the position
(vsnet-campaign-nova 521). M. Fujii performed spectroscopy which
yielded the spectrum with H-alpha H-beta in emission. The emission
lines of Fe II series are prominent, indicating that the object is
a Fe-II class nova (vsnet-campaign-nova 536). There was a temporary
minimum of ~7.5mag around September 9, and then, the object
gradually brightened to 6.8-7.0mag (vsnet-campaign-nova 528, 531,
532, 534, 537, 538, 539, 540, 541, 545, 546).
XTE J1650-500 (RA = 16h50m01s.0, Decl. = -49d57'45")
R. Remillard, RXTE/ASM team, reported that the RXTE/ASM has
detected X-ray emission from a new source, XTE J1650-500.
The first detection was made on September 5.637, with an X-ray
intensity (2-12 keV) of 0.14(.02) Crab, rising to 0.24(.01) Crab
on Sept. 6.432 and 0.27(.01) Crab on Sept. 6.896
(vsnet-campaign-xray 87, vsnet-campaign 1158). It was confirmed
with RXTE/PCA and J. Swank reported that the continuum spectrum
was a power law with a photon index of 1.5 and a small amount
of a black body with kT = 1.2 keV, typical of hard states of black
hole candidates (vsnet-campaign 1160, vsnet-campaign-xray 88).
Its optical counterpart was detected at B=17 and I=17.2+/-0.2 as
reported by Castro-Tirado et al. and Groot et al.
(vsnet-campaign-xray 89, 90, 91).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
As reported by M. Verdenet on September 4, MV Lyr is in outburst
at 14.1mag (vsnet-campaign-nl 27, 28). The object further brightened
on September 5 (vsnet-campaign-nl 29). The outburst continues
(vsnet-campaign-nl 30, 31).
PKS 2155-304 (RA = 21h58m52s, Dec = -30d13'31")
As reported by B. Monard in the last week, this blazar has
further brightened to 12.6-12.9mag (vsnet-campaign-blazar 223, 224).
DM Lyr (RA = 18h58m45s.02, Dec = +30d15'39".9)
As observed by M. Simonsen on September 4, the SU UMa-type dwarf
nova DM Lyr experiences an outburst at 14.5mag (vsnet-campaign-dn
1495). The outburst is ongoing (vsnet-campaign-dn 1505).
RX J1155.4-5641 (RA = 11h55m27.6s, Dec = -56d41'48")
The object experienced an bright outburst of 12.0mag on
September 6 as reported by B. Monard (vsnet-campaign-dn 1509).
GX Cas (RA = 00h49m01s.46, Dec = +56d52'44".8)
As reported by H. McGee on September 9, the SU UMa-type dwarf
nova GX Cas experienced an outburst of 13.8mag, however significantly
faded rapidly (vsnet-campaign-dn 1526).
(continuous targets)
V844 Her (RA = 16h25m01s.69, Dec = +39d09'25".9)
The superoutburst continues and the current magnitude is around
13mag (vsnet-campaign-dn 1479, 1487, 1504, 1513, 1517, 1525).
HO Del (RA = 20h36m55s.49, Dec = +14d03'09".4)
The superoutburst is still ongoing (vsnet-campaign-dn 1493, 1524).
V4739 Sgr = Nova Sgr 2001 No. 2
(RA = 18h24m46s.04, -30d00'41".1)
The nova has further faded. It is now around 12.5mag
(vsnet-campaign-nova 509, 511, 513, 524, 535, 542).
SN 2001du (RA = 03h33m28s.7, Dec = -36d08'32")
IAUC 7704 informed that SN 2001du was revealed as type II
caught on the early phase (vsnet-campaign-sn 237).
V2275 Cyg = Nova Cyg 2002 No. 2
(RA = 21h03m02s.00, Dec = +48d45'52".9)
The object has been smoothly fading (vsnet-campaign-nova 510, 512).
The decline rate became somewhat slower around September 6
(vsnet-campaign-nova 514, 529, 543).
WZ Sge (RA = 20h07m36s.53, Dec = +17d42'15".3)
The rebrightening phenomena are still ongoing (vsnet-campaign-dn
1478, 1480, 1486, 1494, 1497, 1506, 1508, 1512, 1514, 1516, 1523,
1531).
At the top of the seventh rebrightening, eclipses were still
seen and humps became weak (vsnet-campaign-dn 1490). It was faded
on September 3 and the humps were again stronger (vsnet-campaign
1156). The onset of the eighth one was reported on September 4 by
L. Cook (vsnet-campaign-dn 1485, 1488). At the top, no strong QPOs
were detected and two dips (not eclipse) were intensive
(vsnet-campaign-dn 1496, 1499). The object started rapid fading
within one day, which means that the period of rebrightening has
shortened to 1.5 d (vsnet-campaign-dn 1489, 1498). On September 5,
J. Pietz's observation detected the 9-th rebrightening
(vsnet-campaign-dn 1501). D. Starkey's data shows defined humps
and a hard, sharp eclipse during this rebrightening
(vsnet-campaign-dn 1502). The main humps occurred earlier than
before (vsnet-campaign-dn 1503). The hump profile is similar
to that of the 4-th rebrightening, and it may be related to
9-d beat period (vsnet-campaign 1157). After the 9-th rebrightening
had faded, the next 10-th brightening was detected on September 7
by D. Starkey's observations (vsnet-campaign-dn 1511). On the
fading from the maximum, humps and eclipses, which were slightly
earlier than predicted times, clearly appeared (vsnet-campaign-dn
1518, 1521). The rate of the fading seems to become larger
(vsnet-campaign-dn 1519). Possible QPOs were reported in the data
by the Kyoto team (vsnet-campaign-dn 1522). The 11-th rebrightening
was confirmed on September 9. The humps were seen but, eclipses
were not very evident (vsnet-campaign-dn 1528). The phase of humps
were different from those in the last rebrightening
(vsnet-campaign-dn 1529).
On all re-brightenings, the maxima of them have strictly followed
the smooth extension of the decline of the main superoutburst.
The damping nature of the oscillation may be naturally explained at
a constant mass-transfer to the progressively shrinking accretion
disk (vsnet-campaign-dn 1515).
IX Dra (RA = 18h12m32s.2, Dec = +67d04'41")
A possible outburst of 16.0mag was reported on September 8
by M. Reszelski (vsnet-campaign-dn 1527).
V1548 Aql (RA = 19h07m28s.42, Dec = +11d44'45".8)
The object is now around 14.3mag (vsnet-campaign-nova 544).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
Reported observations during the last week indicate that
the oscillation again appeared between <14.2 and 13.0
(vsnet-campaign-dn 1492, 1510).
V818 Sco (RA = 16h19m55s.07, Dec = -15d38'24".5)
The object is still active at around 12.5 (vsnet-campaign-xray
85, 86).
*** Future schedule ***
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]
Supernova campaign: A great opportunity for amateurs
".... Therefore, professionals have been granted HST time
during September, October and November. It will be possible
to obtain both visual (through large telescopes) and UV (HST)
spectra of nearby SNe. The combined data will be used to
verify which models of SNe are correct resulting in the most
valuable data yet gained in the viability of using SNe as
standard candles. HST time is hard to get and it is very
important that as many SNe searching systems are operating
cooperatively during these periods. ...."
(from [vsnet-campaign-sn 233] by M. Schwartz.
For more detailed information, see [vsnet-campaign-sn 233]
*** General information ***
WZ Sge
time-series photometry presented by RIT team:
http://spiff.rit.edu/richmond/ritobs/sep03_2001/sep03_2001.html
[vsnet-campaign-dn 1481]
http://spiff.rit.edu/richmond/ritobs/sep04_2001/sep04_2001.html
[vsnet-campaign-dn 1483]
U-band light curves by A. Henden:
http://ftp.nofs.navy.mil/pub/outgoing/aah/phot/wzsgeui.gif
http://ftp.nofs.navy.mil/pub/outgoing/aah/phot/wzsgeuj.gif
[vsnet-campaign-dn 1482,1484]
light curve presented by L. Cook:
http://vsnet.geocities.com/lcoo/wzsge.htm
[vsnet-campaign-dn 1485]
nightly averaged magnitude, see [vsnet-campaign-dn 1491, 1500, 1520]
time-series photometry by S. Kiyota, see [vsnet-campaign-data 83]
New information on the sequence from A. Henden: [vsnet-campaign-dn 1507]
eclipse ephemeris, see [vsnet-campaign-dn 1530]
V2275 Cyg
multi-color photometry by G. Sostero and A. Lepardo,
see [vsnet-campaign-nova 515 and 547]
XTE J1650-500
optical images:
http://cfa-www.harvard.edu/~pgroot/XTEJ1650-50DDS.ps
http://cfa-www.harvard.edu/~pgroot/XTEJ1650-50OGLE.ps
Images and spectrum by M. Gavin:
http://home.freeuk.com/m.gavin/nsgr01_3.htm
[vsnet-campaign-nova 533]
V4740 Sgr
spectrum by M. Fujii:
http://vsnet1.harenet.ne.jp/~aikow/V4740_Sgr.gif
[vsnet-campaign-nova 536]
(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