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[vsnet-campaign-news 24] News from VSNET 24
*** News from VSNET ***
Delta Vel has been known to be a spectroscopic bynary. S. Otero reported
eclipses of Delta Vel and their possible periods through his several years
monitoring.
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 Oct. 17, 2000, as VSNET campaign circulation 531.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SN 2000dr (RA = 01h01m44s.04, Dec = -15d34'09".1)
H. Yamaoka forwarded the contents of IAUC 7505 which tells the KAIT
discovery of the supernova 2000dr on October 5.3 at about 18.1mag.
The position is about 21" east and 5" south of the nucleus of the
lenticular ((R')SAB0+) galaxy IC 1610. The spectrum shows that
it is a type Ia supernova and typical SNeIa on this distance
(v_r = 5635 km/s) will be about mag 16.0 at their maximum.
CTIO team has observed this SN and the information is loaded at:
http://vsnet.ctio.noao.edu/~nick/sn/sn2000dr/sn2000dr.html. The color
image shows that SN 2000dr at Oct. 7/8 is extremely blue, which
indicates that it is a quite young object (vsnet-campaign-sn 101).
The follow-up observation of this somewhat peculiar SN Ia is highly urged.
SN 2000ds (RA = 09h11m36s.24, Dec = +60d01'42".2)
H. Yamaoka wrote in [vsnet-campaign-sn 102] that T. Puckett and his
colleague has discovered a new faint SN 2000ds in NGC 2768. Its position
is about 9" west and 32" south of the center of this elliptical or
lenticular galaxy. The magnitude at the time of its discovery is 17.9
on October 10.40. Such an early type galaxy as NGC 2768 are thought to
produce only SNeIa. The recession velocity of NGC 2768 is 1373 km/s,
so the expected maximum of typical SNeIa is about mag 13. Almost the same
brightness in 2 days suggest that it is not a young SN Ia. And, typical
SNeIa 140 days after maximum is about 3-4 mag dimmer than at maximum.
The spectroscopic observation is needed for further discussion, and the
follow-up magnitude estimates are also useful. Needless to say, the check
on the pre-discovery image is quite recommended.
Delta Vel (RA = 08h44m42s.1, Dec = -54d42'30")
S. Otero reported the presence of eclipses of Delta Vel. Since 1997 he
has recorded three probable eclipses at 2.2mag instead of its normal 1.95,
estimating the candidates of its period to be 67.7d or 5.88854d, and then,
confirmed the fourth eclipse in JD 2451714.9375 (vsnet-alert 5310).
(continuous targets)
ES Dra (RA = 15h25m32s.26, Dec = +62d00'56".9)
J. Pietz performed CCD time-series photometry on October 7.79 - 7.86.
The analysis revealed no variations above 0.05mag (vsnet-campaign 529).
13.8mag was reported on October 8 by T. Kinnunen and E. Muyllaert
(vsnet-campaign-dn 191).
V503 Cyg (RA = 20h27m15s.61, Dec = +43d41'45".5)
M. Uemura reported the observation on October 9, which yields
the magnitude of 15.07 and no periodic modulation during the 2-hour run
(vsnet-campaign-dn 196).
IY UMa (RA = 10h43m56s.87, Dec = +58d07'32".5)
M. Uemura reported a deep eclipse (depth ~ 2mag) and no clear hump
from the observation on October 9 (vsnet-campaign 530). He also
reported a possible small hump which can be seen in the light curve
observed on October 10 (vsnet-campaign-dn 197) and the object entered
a rapid decline phase from October 10 - 11 (vsnet-campaign-dn 198).
M. Uemura reported the magnitude on October 13.7 to be 16.75
(vsnet-campaign-dn 199).
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
B. Fraser reported his observations on October 12 and 15;V = 1.88:
and 1.91, respectively (vsnet-campaign-be 70).
PKS2005-489 (RA = 20h05m47s.4, -48d58'45".0)
The bright state continues and the current magnitude is about 12.3
(vsnet-campaign-blazer 81).
SY Vol (RA = 08h53m28s.9, Dec = -71d12'29".9)
The fading from the outburst was observed on October 8 by R. Stubbings
(<14.4; vsnet-campaign-dn 194).
CI Aql (RA = 18h52m03.6s, Dec = -01d28m38.9s)
CCD time-series photometry by S. Koyota on September 4, 20 and October 10
was reported in [vsnet-campaign-data 46].
4U 2206+554
T. Watanabe's observation shows the magnitude of this Be-X-ray binary
to be 10.5 on October 11 (vsnet-campaign-xray 57, vsnet-campaign-be 69).
*** General information ***
Delta Vel
eclipse ephemeris presented by S. Otero, see [vsnet-alert 5319]
light curve observed by S. Otero, see [vsnet-alert 5310]
We have set up a new list, vsnet-campaign-deltavel. The new list
"vsnet-campaign-deltavel" is totally devoted to dedicated observing
campaign of Delta Vel.
(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