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[vsnet-campaign-news 40] News from VSNET 40
*** News from VSNET ***
V4018 Sgr = AS 304, a symbiotic stars that have shown P-Cyg profiles,
has dramatically faded to 13.3mag on February 4. Close monitorings
are urged.
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 Feb. 6, 2001, as VSNET campaign circulation 746.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
AQ Eri (RA = 05h06m12s.99, Dec = -04d08'01".6)
The magnitude (13.5mag) on January 29.497 reported by R. Stubbings
has further risen to 12.8mag on January 29.844 as reported by
J. Ripero. The current magnitude suggested a superoutburst.
The last superoutburst of AQ Eri was observed in 2000 Aug
(vsnet-campaign 726). The object however showed relatively rapid
fading, which indicates it was a normal outburst (vsnet-campaign 727,
728; vsnet-campaign-dn 445). The time-series photometry on
January 30 provided by S. Kiyota yields a flat light curve with
a hint of some fluctuations (vsnet-campaign 732).
XTE J1550-564 (RA= 15h50m58s.78, Dec = -56d28'35".0)
According to IAUC 7575, the southern X-ray nova XTE J1550-564 is
brightening again. The source has brightened V=18.3 on Jan. 28-30
(R magnitudes are typically 1 mag brighter). The source was first
observed in outburst in 1998 September (IAUC 7008), whose optical
counterpart (V=16) was immediately discovered. Another outburst
was observed in 2000 April (IAUC 7399, 7400) (vsnet-campaign-xray 61;
vsnet-campaign 730).
AW Gem (RA = 07h22m40s.83, Dec = +28d30'18".5)
The SU UMa-type dwarf nova AW Gem experienced an outburst as reported
by E. Muyllaert (13.6mag) and C. P. Jones (13.0mag) on January 31.
The outburst was suspected to be a superoutburst, as judged from recent
recurrent cycles. The last superoutburst was observed in 2000 May
(vsnet-campaign 733). It however rapidly faded as reported on
February 2. It seems to be a normal one (vsnet-campaign 741).
V383 Vel (RA = 10h21m41s.7, Dec = -49d49'24".33")
As reported by B. Monard, the recently identified dwarf nova,
V383 Vel, again started an outburst on February 1. The last
(first-ever visually detected) outburst occurred on 2000 Dec. 13
(mv=13.1, Stubbings), which rapidly faded as in normal outburst
of SU UMa stars (vsnet-campaign 735). On February 1, A. Pearce's
observation of 12.3mag showed it further brightened (vsnet-campaign 736).
The object however rapidly faded to 13.3mag on February 2
as reported by B. Monard (vsnet-campaign 737). A possible
rebrightening was reported on February 2 (vsnet-campaign 742).
Confirmations that the outburst continues were reported on Febraury 3
(vsnet-campaign-dn 449, 454). It is now in the outburst, and
the current magnitude is about 12.3mag (vsnet-campaign-dn 456).
SN 2001P (RA = 11h53m21s.56, Dec = +20d44'53".3)
SN 2001P has discovered and confirmed on Jan. 31.4 UT and Feb. 1.3
UT, respectively. The discovery magnitude is reported as 17.5:C.
The location is about 17" east and 13" south of the nucleus of
the barred-spiral galaxy NGC 3947. From the recession velocity
of NGC 3947, the expected maximum for normal SN Ia is about mag 16.
Note that NGC 3947 has produced SN 1972C, which was caught at m_p = 16.
The Spectroscopy of SN 2001P has revealed that it is of type Ia
about a week past maximum, and it seems to be subluminous
(vsnet-campaign-sn 148).
SN 2001Q (RA = 11h25m19s.77, Dec = +63d43'15".6)
SN 2001Q was discovered on Jan 31.4 UT (mag18.6:C) and confirmed
on Feb. 1.3 (mag 18.3:C), which indicate that it is in rising.
The position is about 4" east and 30" south of the nucleus of
the dim face-on spiral galaxy UGC 6429. From the recession velocity
of UGC 6429, the expected maximum for normal SN Ia is about mag 15.
The spectrum of SN 2001Q shows that it is young type II SN
(vsnet-campaign-sn 148).
GK Per (RA = 03h31m12s.50, Dec = +43d54'17".8)
Several observers reported that GK Per is brighter than usual
on January 30 (vsnet-campaign 739).
CT Hya (RA = 08h51m04s.50, Dec = +03d07'43".5)
CT Hya experienced an outburst at 14.8mag as reported by
R. Stubbings on February 2 (vsnet-campaign-dn 446).
V4018 Sgr (RA = 18h25m29s.95, Dec = -28d35'09".5)
B. Monard reports that the symbiotic variable V4018 Sgr = AS 304
has dramatically faded to 13.3mag on February 4. Such a fading may
be an eclipse, or dramatic decrease of activity (vsnet-campaign 743,
vsnet-campaign 744, 745).
(continuous targets)
QW Ser (RA = 15h26m13s.99, Dec = +08d18'03".8)
The outburst rapidly faded on January 30, which indicates it
is a normal outburst (vsnet-campaign 731). The object again started
an outburst, as recorded in Kyoto Feb. 2 observation, which is
the very signature of the transition to a genuine superoutburst
(vsnet-campaign 740).
SX LMi (RA = 10h54m29s.93, Dec = +30d06'30".0)
The superoutburst continues (vsnet-campaign-dn 452).
BF Eri (RA = 04h39m29s.62, Dec = -04d36'10".0)
The long outburst continues (vsnet-campaign-dn 440, 451).
The current magnitude is about 12.7mag.
RX J0640-24 (RA = 06h40m47s.72, Dec = -24d23'14".5)
The object again experienced an outburst at 14.0mag on February 3
as reported by R. Stubbings (vsnet-campaign-dn 453).
U Gem (RA = 07h55m05s.55, Dec = +22d00'09".2)
The slightly bright state at 13.6 - 14.5 continues
(vsnet-campaign-dn 439).
V342 Cen (RA = 11h07m15s.82, Dec = -55d57'32".7)
The outburst was slowly fading (vsnet-campaign-dn 448).
RX J1155.4-5641 (RA = 11h55m27s.03, Dec = -56d41'53".3)
The long outburst faded (vsnet-campaign-dn 441).
The brightness is still above the quiescence (vsnet-campaign 738;
vsnet-campaign-dn 450). The current magnitude is about 14.2mag.
V445 Pup (RA = 07h37m56s.88, Dec = -25d56'59".1)
The object keeps the relatively quiet state at about 9.5mag
until January 30 when S. Otero reported that the ALDA team observed
a temporary fading to 10.4mag (vsnet-campaign-nova 196).
The fading was confirmed by LIADA observations as reported by
S. Otero (vsnet-campaign-nova 197, 198, vsnet-campaign 725).
Several observers in Japan independently recorded short-term
variability of the object (vsnet-campaign-nova 199, 200).
The object was then recovered (vsnet-campaign 201, 202, 203),
and then, continues fading (vsnet-campaign-nova 204, 205).
3C 66A (RA = 02h22m39s.6, Dec = +43d02'08")
An observation on February 1 by D. Rodriguez shows a possible
brightening to V=14.2mag (vsnet-campaign-blazar 140).
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
The bright state continues (vsnet-campaign-be 83, 84).
The current magnitude is about 1.9mag.
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
An outburst (13.2mag) was reported on February 1.042 by
B. Monard (vsnet-campaign-dn 442). S. Walker noticed that
it is the ~23 hour normal outburst cycle which occurs daily
(vsnet-campaign-dn 443). A. Pearce reported fading from the
outburst (<15.0mag) on February 1.831 (vsnet-campaign-dn 444).
R. Stubbings' observation on February 2.685 shows another
outburst (vsnet-campaign-dn 447, 455).
Delta Vel (RA = 08h44m42s.1, Dec = -54d42'30")
An eclipse (1.9mag) on February 1 was reported by M. Mattiazzo
(vsnet-campaign-deltavel 35).
SN 2001B (RA = 04h57m19s.24, Dec = +78d11'16".5)
SN 2001B (vsnet-alert 5523, vsnet-campaign-sn 126) has been
revealed as of type Ib, not Ia as reported earlier. Jan. 23
spectrum tells that it was about 1 week past maximum, which is
coincident with vsnet-reported observations (max around mag 14.5
at Jan 15). Generally, SN Ib has a maximum 1 magnitude dimmer
than normal SN Ia. As the expected maximum for SN Ia was 13.3,
the vsnet light curve shows very good agreement with it.
Also, SN Ib tend to show slower decline than SN Ia, so it will
remain bright longer. After the separation of subtype SN Ic,
SN Ib has little been discovered and observed (vsnet-campaign-sn 149).
*** Future schedule ***
RZ LMi campaign conducted by J. Patterson on April 2001
J. Kemp forwarded an invitation of RZ LMi campaign conducted by
J. Patterson on April 2001:
"Since the work of Robertson et al. 1995 (PASP 107, 443) and Nogami et
al. 1995 (PASJ 47, 897), this star has been known to be the most frantic
dwarf nova in the sky, with superoutbursts popping off every 20
days. Five years ago we conducted a long CBA campaign, and found two
tantalizing results: that the superhumps did not die in quiescence (as
required by law), and that they did not lose track of phase from one
superoutburst to the next (as required by another law). The data were
not, however, sufficient to prove either of these beyond doubt."
Time-series observations, especially longer than 3 hours, will
be welcomed. For more general information about observations,
see "http://cba.phys.columbia.edu" and click on "data" and "charts".
If you are interested in this campaign, please contact with J. Patterson
(jop@astro.columbia.edu).
[vsnet-campaign 718, vsnet-campaign-dn 429]
*** General information ***
U Gem
eclipse ephemeris, see [vsnet-campaign 729]
(This summary is reproduction free.)
Regards,
Makoto Uemura
vsnet-adm@kusastro.kyoto-u.ac.jp
Return to Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
VSNET Home Page