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[vsnet-campaign-news 13] News from VSNET 13
*** News from VSNET ***
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.
Regards,
Taichi Kato
On behalf of the VSNET administrator team
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The spectacular event announced in the last week news - the HISTORICAL
OUTBURST of delta Scorpii - is still ongoing. The news from VSNET and
SkyPub has been now distributed worldwide, and are among the important
press matters in several countries! We have received considerable attention
from the SkyPub news readers, and received observations. The following URLs
will help visiting this star.
* Charts with magnitudes (created by Tsutomu Watanabe, VSOLJ):
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-j-deltasco/msg00011.html
(The main text is in Japanese, but the image will look ok).
* Latest light curve (requires Java):
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/etc/drawobs.cgi?text=SCOdelta
The key VSNET lists on delta Sco are vsnet-be and vsnet-campaign-be.
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-be/maillist.html
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-campaign-be/maillist.html
Several interesting dwarf novae are reported in outburst, and await
follow-up observations. The likely superoutburst of DH Aql is fresh,
and is a promising target for CCD observers. We also have a prediction
by Tsutomu Watanabe, the renowned astronomical future-teller of the world,
of the next outburst of HT Cas, one of the most awaited phenomenon by many
astronomers. There had never been such an outburst prediction of this
extremely important dwarf nova. Please closely look at this dwarf nova,
and report to the VSNET (vsnet-adm [or vsnet-alert, if you have a
subscription account of VSNET]) immediately if you find any change!
There is also an invitation to coordinated observations with Chandra
and HST, on recent novae (see the text).
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).
*** New Mailing Lists of the Week ***
The following VSNET mailing lists are newly available:
vsnet-unknown: variable stars with unknown classification
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-unknown/maillist.html
vsnet-jet: astrophysical jets; associated variable stars
vsnet-announcement: announcements from VSNET
vsnet-recent sub-lists (recent summaries of observations):
vsnet-recent-blazar : blazars (BL Lac objects and QSOs)
vsnet-recent-sn : Supernovae
vsnet-recent-nova : Novae
vsnet-recent-xray : X-ray binaries, X-ray novae
vsnet-recent-rcb : R CrB stars
vsnet-recent-symbio : symbiotic variables
vsnet-recent-nl : novalike variables
vsnet-recent-polar : AM Her-type variables
vsnet-id sub-lists (identifications):
vsnet-id-2mass-var : 2MASS-selected variable star candidates
If one wish to subscribe to any of new lists, send a message to
vsnet-adm@kusastro.kyoto-u.ac.jp with a body line (for example)
SUBSCRIBE vsnet-unknown your e-mail address
SUBSCRIBE vsnet-recent-nova your e-mail address
etc.
Or, look at the list information page for more details:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/information.html
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The following was issued on Jul. 31, 2000, as VSNET campaign circulation 405.
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SY Vol (RA = 08h53m28s.9, Dec = -71d12'29".9)
R. Stubbings reported that the suspected dwarf nova SY Vol is probably
undergoing a bright outburst (14.2mag on July 23). The quiescent
counterpart seems to be USNO0150.05620695 whose magnitude is about 22.
The object is also has a likely ROSAT detection (vsnet-campaign 390).
The observations by R. Stubbings showed it was still bright on July 27
(vsnet-campaign 399).
Considering the large-amplitude of the outburst, the star may be an
SU UMa-type dwarf nova undergoing a rare superoutburst. Observations
are strongly encouraged.
XTE J1859+226 (RA = 18h58m41s.58, Dec = +22d39'29".4)
This X-ray nova was detected on 1999 October. M. Garcia et al. reported
in IAUC 7466 that further observations of the optical counterpart to this
soft x-ray transient which recently underwent optical and x-ray re-flares.
Observations with the CTIO 0.9m telescope on July 23.1, 24.1, and 25.1
(UT) find R = 20.8 +/- 0.3, 20.2 +/- 0.1, 19.8 +/- 0.1
(vsnet-campaign-xray 24).
The activity in this phase is very interesting.
V592 Her (RA = 16h30m51s.60, Dec = +21d17'35".5)
The possible outburst was reported on July 25 (vsnet-campaign 396).
S. O'Connor confirmed that the star was near quiescence on July 26
and no likely outburst (vsnet-campaign 397).
BR Lup (RA = 15h35m51s.61, Dec = -40d34'25".4)
The SU UMa-type dwarf nova BR Lup was reported to be undergoing a bright
outburst, possibly superoutburst (13.7mag on July 27). The last
superoutburst of this star was reported in 2000 March.
Now it is in outburst. Time-series photometry is encouraged to make
clear the nature of this outburst.
V503 Cyg (RA = 20h27m15s.61, Dec = +43d41'45".5)
C. Bryja noticed that this SU UMa star with an orbital period of less than
2 hours has been performing a Z Cam like standstill at V~15.7 ongoing since
July 20th (vsnet-campaign 402).
The nature of this object is still unknown, and dense observations to
reveal the outburst or standstill behavior is encouraged.
V1008 Her (RA = 18h05m46s.4, Dec = +31d40'18")
The outburst of this dwarf nova was reported by C. P. Jones on July 29
at 13.0mag. Despite that this star is most likely an SS Cyg-star based
on the last (1999 November) observations, the good seasonal visibility
and bright maximum would place the present outburst as a potential
detailed follow-up target (vsnet-campaign 403). Now it is in outburst.
DH Aql (RA = 19h26m12s.05, Dec = -10d15'21".4)
R. Stubbings reported that the SU UMa-type dwarf nova DH Aql was
undergoing a bright outburst (12.6mag on July 31). The last superoutburst
was observed in 1999 April (mv=12.4, Pearce). Now it is in outburst.
The superhump period of this object has not been well established
(vsnet-campaign 404). Time-series observations are strongly urged.
(continuous targets)
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
E. Pollmann posted the spectra (R = 2188, S/N = 480; with Maksutov
objective prism spectrograph) to [vsnet-campaign-image 2] (or
vsnet-campaign-be 8). S. Otero reported that J. Fabregat (University of
Valencia, Spain) informed he has been receiving several spectra taken in
the past. From these, the emission lines have been present, although with
variable strength, for at least five years. So we're not witnessing the
birth of delta Sco as a Be star but its birth as a gamma Cas variable
(vsnet-campaign-be 9). T. Kato forwarded the D. Dunham's report that
the next occultation of delta Scorpii occur on 2003 Sep. 2, and the other
days are listed in [vsnet-campaign-be 14]. S. Masuda (Kyoto University)
provided a high-dispersion spectrum of delta Sco on July 26
(vsnet-campaign-be 15). The object still keeps the gradual brightening
trend.
V4641 Sgr (RA = 18h19m21s.6, Dec = -25d24'25")
No remarkable brightening was reported during the last week.
SN 2000cx (RA = 01h24m46s.15, Dec = +09o30'30".9)
K. Krisciunas reported his observation and commented that it is curious
that the B-V color has stayed so constant (vsnet-alert 5156,
vsnet-campaign-sn 28). The object is brighter than expected magnitude
of typical SNeIa, and seems to reach a peak around July 26
(vsnet-campaign-sn 30).
Close monitorings are encouraged.
V792 Cyg (RA = 19h31m00s.50, Dec = +33d47'11".8)
This dwarf nova which was reported to be in a bright outburst
faded like SS Cyg-type (vsnet-campaign-dn 62). Now it is at
quiescence.
1H 1933+510 (RA = 19h34m36s.08, Dec = +51d07'42".2)
The report from S. O'Connor that this brightening nova-like variable
was at 15.8mag on July 24 was apparently confirmed the outburst
(vsnet-campaign 392). C. Bryja reported that the object is North 4.3 arcsec
and West 12.0 arcsec from a bright comparison star, GSC 3568-115 and
the result of the absolute photometry of this comparison star
(vsnet-campaign 393, 394). A rather hasty fade was reported on July 25
by S. O'Connor (16.5mag) (vsnet-campaign 395). C. Bryja provided
the photometry of the GSC stars in the CCD field (vsnet-campaign 398).
The current magnitude indicates the object is near its low-state.
V2051 Oph (RA = 17h08m19s.1, Dec = -25d48'31".1)
The fading trend from the outburst was reported on July 24.
The normal outburst was ended (vsnet-campaign-dn 61).
TT Ind (RA = 20h33m39s.79, Dec = -56d33'43".8)
Further brightening of this dwarf nova in a rare outburst had been
observed on 24 July (vsnet-campaign 391). It started fading on July 28
(13.2mag), suggesting a possible long outburst of an SS Cyg star
(vsnet-campaign-dn 70).
V844 Her (RA = 16h25m01s.69, Dec = +39d09'25".9)
The fading from the superoutburst started, and then, the object was
experiencing a stage of slight brightening before the termination of
the superoutburst (July 26 - 29) (vsnet-campaign-dn 73).
Observations at this stage is important since superhumps tend to show a
regrowth (see Baba et al. 2000, V1028 Cyg).
CI Aql (RA = 18h52m03s.6, Dec = -01d28m38.9s)
This nova keeps the fading trend. A possible rapid decline was
noticed (vsnet-campaign-nova 70). More time-series observations,
particularly including eclipses, are strongly encouraged.
V803 Cen (RA = 13h23m44s.5, Dec = -41d44'30".1)
Striking oscillations have been observed, however, fainter trend
can be seen in the recent data (vsnet-campaign-dn 59, 64, 68).
BL Lac (RA = 22h02m42s.86, Dec = +42d16'37.6")
During the last week, a gradual brightening was observed
(vsnet-campaign-blazer 46).
XTE J1118+480 (RA = 11h18m10s.9, Dec = +48d02'12".9)
M. Uemura reported the preliminary results of the data obtained during
JD 2451740 - 2451750 at Kyoto. This X-ray nova keeps the relatively
rapid decline (0.044 mag/d). From around JD 2451730, the multiple peaks
appeared in light curves, and we confirmed it is a real feature through
the light curve during JD 2451740 - 2451750 (vsnet-campaign-xray 25).
Recent visual observations by M. Verdenet on July 26 (13.7mag) also seem
to confirm the trend (vsnet-campaign-xray 26).
(outburst predictions)
HT Cas (RA = 01h10m07s.74, Dec = +60d04'03".6)
As predicted by T. Watanabe that the next outburst of HT Cas occurs
either between 2000 Aug 3 and 17 or between November 8 and 22, it may
erupt in immediate future. If it erupts, the object will be the highest
priority target for the VSNET collaboration team (vsnet-campaign 401).
*** Future schedule ***
V382 Vel, V1494 Aql, Nova in LMC 2000 campaign
(August 7) (August 21)
S. Starrfield and his collaborators will be obtaining CHANDRA
observations of V382 Vel and V1494 Aql the week beginning August 7, 2000
and they will be obtaining HST/STIS observations of Nova LMC 2000 the
week of August 21, 2000. Ground based observations are encouraged.
Observers those who are interested in this campaign, should contact
with Dr. Starrfield (sumner.starrfield@asu.edu).
[vsnet-campaign-nova 71]
BL Lac campaign (July 17 - August 11)
Massimo Villata, Gino Tosti, and Enrico Massaro organize an
optical campaign on BL Lac contemporaneous with the high-energy
campaign involving X-ray and TeV observatories such as BeppoSAX,
RXTE, STACEE, CAT, HEGRA. Their goal is high-density and
high-precision coverage, possibly in two optical bands (B and R).
Observers interested in participating to this optical campaign are
invited to contact with M. Villata (villata@to.astro.it).
[vsnet-campaign 204]
NY Ser spectroscopic observations at the Calar Alto Observatory
(July 08/09 and 09/10)
D. Nogami noticed their schedule of spectroscopic observations of
NY Ser and wrote: "Because it is quite important for us to know the
state of NY Ser at our observations as accurately as possible, we would
ask observers to make a close monitor of this star for ~1 month from
now (this article was posted on June 29)."
For more information, please see [vsnet-campaign 265], or contact
with D. Nogami (daisaku@uni-sw.gwdg.de).
[vsnet-campaign 265]
V446 Her campaign (throughout this summer)
Boris T. Gaensicke organize a campaign on the post nova V446 Her (V~18).
Their aim is to obtain a *good* contiguous light curve of V446 Her that
covers 2-3 dwarf nova-like outbursts of the system, in order to compare
its outburst characteristics to those of ``normal'' dwarf novae.
They invite those of you equipped with a CCD camera to obtain a couple
of images of V446 Her per night throughout the next three months, say,
until the end of September.
For more information, please see [vsnet-campaign 325] or contact
with Boris T. Gaensicke (boris@uni-sw.gwdg.de).
In [vsnet-campaign 368].....
"The V446 Her campaign from July 7 was started (through the end of
September). But we have received very few observations since then.
Negative observations, for instance, <17.0, are also useful.
We strongly encourage observers to contribute to this project.
Let's clarify the physics of post novae!"
*** General information ***
SN 2000cx
preliminary SN 2000cx field star photometry (provided by K. Krisciunas).
http://vsnet.astro.washington.edu/kevin/apo.html
and [vsnet-campaign-sn 25]
Delta Sco
Spectra (From E. Pollmann), see [vsnet-campaign-image 2]
High-dispersion spectra (From Izumiura and Masuda);
[delta Sco]
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Be/Delta_Sco/deltasco.gif
[tau Sco, for comparison (B0V star)]
http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/Be/Delta_Sco/tausco.gif
1H 1933+510
Photometry of field stars provided from C. Bryja, see [vsnet-campaign 398]
XTE J1118+480
New light curves can be seen at:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Xray/xtej1118-camp.html
[vsnet-campaign-xray 25]
HT Cas
eclipse ephemeris, see [vsnet-campaign-dn 72]
(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