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[vsnet-campaign-news 67] News from VSNET
*** News from VSNET ***
The superoutburst of AL Com is still ongoing. Rare outburst of
V551 Sgr 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 May. 28, 2001, as VSNET campaign circulation 944.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V551 Sgr (RA = 18h00m56s.46, Dec = -34d35'45".6)
A. Pearce reported that the dwarf nova V551 Sgr is undergoing a
relatively rare outburst. The last outburst was in 2000 April.
The object has been claimed to be a possible WZ Sge-like object,
based on its large outburst amplitude. One the occasion of the
1998 October outburst, G. Garradd obtained time-series photometry
on two nights, but the short visibility hindered a firm conclusion
on the existence of superhumps. The present outburst, if confirmed,
would provide an excellent opportunity to study this
still poorly understood dwarf nova (vsnet-campaign 941).
The outburst is still ongoing, and the last reported magnitude is
14.8mag (vsnet-campaign-dn 840).
SN 2001br (RA = 18h30m25s.55, Dec = +34d06'13".0)
IAUC 7627 reports that M. Armstrong discovered a bright SN 2001br.
The position is 2" east and 2" north of the nucleus of the SBb
galaxy UGC 11260. Spectroscopy revealed that it is of type Ia SN
near the maximum. It was 16.0mag on May 21. The expected magnitude
of typical SN Ia is about 16.5mag, so it can be intrinsically
somewhat bright SN (vsnet-campaign-sn 197).
StHa-164 (RA = 19h26m01s, Dec = -06d09'53")
S. O'Connor reported the object is currently at R=12.84 and
V=14.20 which indicate slightly brightening (vsnet-campaign 927).
V893 Sco (RA = 16h14m45s.26, Dec = -28d39'30".3)
Reported observations on May 20 - 23 implies the object became
somewhat fainter (vsnet-campaign-dn 812). On May 25, it experienced
an outburst at 12.9mag as reported by R. Stubbings. M. Uemura
performed time-series observation of an eclipse in the same day
(vsnet-campaign 932). The outburst continued until May 27
(vsnet-campaign-dn 824, vsnet-campaign 942, vsnet-campaign-dn 842, 844).
HS Vir (RA = 13h43m38s.5, Dec = -08d14'04".1)
The SU UMa-type dwarf nova HS Vir is undergoing a possible
superoutburst, as reported by P. A. Dubovsky. The last
superoutburst occurred in 2000 May (vsnet-campaign 930).
The observation on May 25 by R. Stubbings shows possible fast
fading (vsnet-campaign-dn 828). A. Pearce's observation shows
it remain the similar magnitude on May 26 (vsnet-campaign-dn 835).
The long duration indicates the outburst is a superoutburst, and
the current magnitude is about 13th (vsnet-campaign-dn 838).
V660 Her (RA = 17h42m07s.3, Dec = +23d47'37".3)
The SU UMa-type dwarf nova V660 Her is undergoing a relatively
rare outburst as reported by P. A. Dubovsky. The last reported
outburst dates back to 2000 June (vsnet-campaign 931). J. Pietz
detected superhumps during 1999 superoutburst (vsnet-campaign 936).
M. Reszelski's observation on May 26 shows the object further
brightened to 14.7mag (vsnet-campaign 935).
SN 2001bt (RA = 19h13m46s.75, Dec = -59d17'22".8)
SN 2001bt was discovered by R. Chassagne. The position is 27".7
west and 17".1 north from the center of the host galaxy.
The host galaxy IC 4380 is a barred-spiral galaxy, and the SN is
superimposed on the disk region. The expected maximum of SN Ia is mag
about 15.5, but the discovery magnitude (15.0mag) is exceed it
(vsnet-campaign-sn 200).
RX J0640-24 (RA = 06h40m47s.72, Dec = -24d23'14".5)
B. Monard detected an outburst on May 25 at magnitude 12.0
(vsnet-campaign-dn 834).
BF Ara (RA = 17h38m10s.40, Dec = -47d10'43".4)
As reported by A. Pearce on May 27, BF Ara experienced an
outburst at 14.3mag (vsnet-campaign-dn 841).
V383 Vel (RA = 10h21m41s.7, Dec = -49d49'24".33)
As reported by A. Pearce on May 27, V383 Vel experienced an
outburst at 12.9mag (vsnet-campaign-dn 843). B. Monard's observation
on May 27 implies its further brightening (vsnet-campaign-dn 845).
(continuous targets)
Nova Aql 2001 (RA = 19h07m28s.42, Dec = +11d44'45".8)
The object seems to become slightly brighter since May 21
(vsnet-campaign-nova 318, 321, 322), and then, again start gradual
fading (vsnet-campaign-nova 325, 327). The fading trend possibly
stopped in the end of the last week (vsnet-campaign-nova 329).
N.James reported his re-reduced photometry from May 16 to 23
(vsnet-campaign-nova 324).
AL Com (RA = 12h32m25s.90, Dec = +14d20'42".5)
The VSNET collaboration team has received data sets from R. Novak,
P. Sobotka, K. Hornoch, G. W. Willings, B. Martin, J. Pietz, G. Masi
(vsnet-campaign 918, 923, 924, 925, vsnet-campaign-dn 806, 810, 817,
818, 823, 831, 832, 846). The superoutburst is still ongoing
(vsnet-campaign-dn 802, 805, 808, 815, 821, 825, 833, 839).
The data on May 19 and 22 shows 0.05672(2)d periodicity which is
consistent with the orbital period and the profile of the humps has
double peaks. The light curve became relatively flat since May 21.
The nightly decline rate is about 0.2mag/d (vsnet-campaign-920,
vsnet-campaign-dn 813). The data by Brno team on April 24 and 25
shows single peaked humps with the same period (vsnet-campaign 929).
In the light curve on May 25 taken at Kyoto, humps with a possible
longer period are detected (vsnet-campaign 933). G. Masi reported
the detection of ~0.25mag humps with a period of 0.053 or 0.055 d
(vsnet-campaign 943). The nightly decline rate became slow in
May 24 and 25 (vsnet-campaign-dn 826)
MM Hya (RA = 09h14m13s.97, Dec = -06d47'45".0)
The superoutburst continues. The current magnitude is 14-15mag
(vsnet-campaign-dn 826).
V503 Cyg (RA = 20h27m15s.61, Dec = +43d41'45".5)
The superoutburst continues. 13.4mag was reported on May 21
(vsnet-campaign-dn 803).
IP Peg (RA = 23h23m08s.7, Dec = +18d24'59".1)
The outburst continued until May 25 (vsnet-campaign-dn 816, 820).
SN 2001bg (RA = 08h35m18s.86, Dec = +28d28'05".8)
The object is gradually fading (vsnet-campaign-sn 199, 202).
The CfA group also took a spectrum of SN Ia 2001bg, which shows deep
absorption lines by the interstellar medium both in the host galaxy
and in our Galaxy (IAUC 7626). It suggests that SN 2001bg suffers
a deep extinction (A_V ~ 2 mag), and the expected maximum on previous
messages are overestimated (vsnet-campaign-sn 204).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
The object is oscillating between 13.1-13.9 (vsnet-campaign-dn 807).
3C 279 (RA = 12h56m11s.1, Dec = -05d47'20")
The object is still active around 14mag (vsnet-campaign-blazar 198, 199).
CR Boo (RA = 13h48m55s.42, Dec = +07d57'30".3)
Reported observations during May 14 - 20 seem to imply some
oscillation around 14mag (vsnet-campaign-dn 804). The outburst
seems to be terminated during the last week (vsnet-campaign-dn 809),
and then, another outburst was reported on May 24 (vsnet-campaign-dn 819).
V445 Pup (RA = 07h37m56s.88, Dec = -25d56'59".1)
Another brightening to 10.3mag was reported on May 23
(vsnet-campaign-nova 323).
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
S. Otero reported that the object became slightly fainter on
May 24 (vsnet-campaign-be 131).
IX Dra (RA = 18h12m32s.2, Dec = +67d04'41")
As reported by G. Poyner and M. Reszelski, the SU UMa-type dwarf
nova IX Dra experienced an outburst reported on May 19. The duration
of the outburst suggests a superoutburst. The last superoutburst
occurred on Apr. 13 (vsnet-alert 5810 and 5812). If the present
outburst is a genuine superoutburst, the supercycle becomes as
short as 36 d, which qualifies the ER UMa nature (vsnet-campaign 926).
The possible superoutburst was terminated on May 25 when M. Uemura
reported the faint (17.1mag) magnitude of the object
(vsnet-campaign-dn 827).
DI UMa (RA = 09h12m22s.16, Dec = +50d49'39".1)
The possible superoutburst seems to be terminated during the
last week (vsnet-campaign-dn 830).
SN 2001X (RA = 15h21m55s.46, Dec = +05d03'43".1)
This SN almost remain its magnitude at 15.5 (vsnet-campaign-sn 203).
MV Lyr (RA = 19h07m15s.93, Dec = +44d01'10".7)
The object is now very faint (<16.2mag) (vsnet-campaign-nl 22).
ST Cha (RA = 10h47m31s.3, Dec = -79d27'17")
R. Stubbings' observation on May 25 shows the object again faded
(vsnet-campaign-dn 829).
V4018 Sgr (RA = 18h25m29s.95, Dec = -28d35'09".5)
The fading trend continues. The current magnitude is about
13.7mag (vsnet-campaign 937).
*** Future schedule ***
Elizabeth and Frederick White Workshop
AGN variability across the Electromagnetic Spectrum
25 - 29 June 2001 Sydney, Australia
For more information, see [vsnet-campaign-blazar 168].
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 ***
AL Com
VSNET page for 2001 May superoutburst:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/alcom0105.html
[vsnet-campaign 921, 922, 928]
CCD image by R. Novak:
http://codel.astronomy.cz/planetka.jpg - an combined image obtained here
[vsnet-campaign 939]
CCD image by G. Masi:
http://vsnet.eurolink.it/comets/galaxies.html
[vsnet-campaign 940]
Nova Aql 2001
sequence presented by A. Henden:
http://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/naql01.dat
chart presented by R. Bouma and E. van Dijk:
http://vsnet.shopplaza.nl/astro/vs-charts/nova2001aql1.htm
chart presented by O. Trondal:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Novae/nova_aql01/trondal.jog
[vsnet-campaign-nova 326, 328]
SN 2001bg
sequence presented by B. Sumner, see [vsnet-campaign-sn 198]
V893 Sco
eclipse ephemeris, see [vsnet-campaign-dn 822]
V803 Cen
The result of VSNET campaign on V803 Cen is accepted for publication
as IBVS No. 5091, see [vsnet-preprint 24] and figures are placed at:
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/preprints/V803_Cen-2/
[vsnet-campaign 934]
(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