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[vsnet-campaign-news 33] News from VSNET 33
*** News from VSNET ***
The observations by J. McClintock, M. Garcia and their collaborators
show that XTE J1118+480 contains a black hole of at least 6 solar masses.
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 Dec. 19, 2000, as VSNET campaign circulation 583.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
V383 Vel (RA = 10h21m41s.7, Dec = -49d49'24".33")
As reported by R. Stubbings on December 13, the new dwarf nova
V383 Vel = NSV04834 experienced an outburst at 13.1mag(vsnet-campaign 582).
Recent observations indicates the outburst was terminated on December 16
(vsnet-constel-vel 133).
CY UMa (RA = 10h56m57s.69, Dec = +49d41'09".1)
As reported by E. Muyllaert on December 14, the SU UMa-type dwarf nova
CY UMa is in outburst at 12.5mag. The interval suggests a superoutburst.
The last superoutburst was observed in 1999 Dec. - 2000 Jan
(vsnet-campaign-dn 311). M. Uemura and the Kyoto team performed a
time-series CCD observations at Kyoto on December 15 and reported
the magnitude of about 12.4 (vsnet-campaign-dn 316).
3C 66A (RA = 02h22m39s.6, Dec = +43d02'08")
The blazar 3C66A is bright, as indicated by observations showing the
magnitude of about 14.2mag on December 15 (vsnet-campaign-blazar 111).
(continuous targets)
VZ Pyx (RA = 08h59m20s.0, Dec = -24d28'56".1)
The superoutburst continues. The current magnitude seems to be fainter
than 13.2 (vsnet-campaign-dn 309, 314, vsnet-constel-pyx 83).
CT Hya (RA = 08h51m04s.50, Dec = +03d07'43".5)
L. Cook reported that S. Kiyota's data on December 4 shows 0.0673 d
periodicity (vsnet-campaign-data 51). He also reported that using
combined data on December 2 and 4, the period analysis shows the candidates
of 0.0664 day and 0.0688 day (vsnet-campaign-data 52).
V503 Cyg (RA = 20h27m15s.61, Dec = +43d41'45".5)
R. Ishioka and the Kyoto team reported another outburst on December 9
(vsnet-campaign-dn 303).
TY PsA (RA = 22h49m40s.31, Dec = -27d06'54".3)
The superoutburst continued until December 13 when A. Pearce reported
the magnitude of 12.8 indicating it entered a rapid decline phase
(vsnet-campaign-dn 304, 308, 315).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
The object became fainter. The observation by B. Monard shows the
magnitude on December 15 was fainter than 13.9(vsnet-campaign-dn 313).
OY Car (RA = 10h06m22s.46, Dec = -70d14'04".4)
The rapid fading from the current outburst started around December 12
as reported by R. Stubbings and A. Pearce (vsnet-campaign 306, 310).
BL Lac (RA = 22h02m42.86s, Dec = +42d16'37.6")
The activity still continues. The magnitudes of 13.9-14.3 were reported
during the last week (vsnet-campaign-blazar 112).
XTE J1118+480 (RA = 11h18m10s.9, Dec = +48d02'12".9)
M. Garcia and his collaborators performed spectroscopic observations
of X-ray nova XTE J1118+480 with the new 6.5-m MMT on Dec. 1 & 4
and reported a velocity amplitude of 698 +/- 11 km/s and an orbital
period of 0.1701 +/- 0.0003 days, which give a mass function of
6.0 +/- 0.3 solar masses. The large value of the mass function is rivaled
only by that of V404 Cyg (vsnet-campaign-xray 58, 59).
*** Future schedule ***
TV Col campaign conducted by A. Retter (2001 January 2 - 15):
"Recently using previously published data, we discovered evidence for
another periodicity in the light curve of TV Col. The 6.4-h period would
be the longest recorded positive superhump. To confirm this period, I'll
carry out continuous photometry on TV Col during two weeks in January
(2-15) using the 0.75-m reflector with the UCT CCD in Sutherland, South
Africa.
I am calling for a campaign on TV Col during these nights. As the
candidate periodicity is relatively long, multi-longitude continuous
monitoring of the object is extremely important to reduce the aliasing
problem. So, if you can observe the object for at least ~4 h (preferably
more than one 6.4-h cycle), please let me know."
for more information, see [vsnet-campaign 579],[vsnet-campaign-ip 15]
*** General information ***
OY Car
eclipse ephemeris, see [vsnet-campaign-dn 305].
(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