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[vsnet-campaign-news 39] News from VSNET 39
*** News from VSNET ***
The high energy activity of the BL Lac object Markarian 421
recorded the brightest X-ray flux seen from a BL Lac object
during the RXTE Mission.
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 Jan. 30, 2001, as VSNET campaign circulation 724.
[Note a large part of detailed information is posted to vsnet-campaign
sub-lists].
VSNET Weekly Campaign Summary
*** Last week news ***
(new targets)
SN 2001M (RA = 10h24m31s.48, Dec = -21d47'40".6)
SN 2001M was discovered and confirmed on Jan. 21.4 UT (mag 175:C)
and Jan. 22.4 UT (mag 177:C), respectingly. The location is about
12" east and 12" south of the nucleus of a face-on spiral (SAB(rs)b)
galaxy NGC 3240. This galaxy has a bright nucleus, but the new
object is well outside of the central region and embedded on the
outer disk. There is mag 14 foreground star whose offsets from
the nucleus of NGC 3240 are about 22" east and 42" south.
The recession velocity of the host galaxy (3584 km/s) suggests that
expected maximum of a normal SN Ia would be mag 15.1
(vsnet-campaign-sn 139).
SN 2001N (R.A. = 10h39m58s.08, Dec = +24d05'26".0)
SN 2001N was discovered and confirmed on Jan. 21.4 UT (mag 163:C)
and Jan. 22.4 UT (mag 162:C), respectingly. The location is very
close (3" SE) of the bright nucleus of a face-on spiral (SA(r)b)
galaxy NGC 3327. There are some foreground stars: a mag 14 star
(GSC 1977-815, GSCmag(close to V)=14.09, USNO r=14.6, b=16.4 about
24" west of the nucleus of NGC 3327, and a mag 17: star (USNO_A2.0
position is end figures 57s.26, 57".6, r=17.1, b=17.6) about 9" west
and 29" north of the nucleus. The recession velocity of the host
galaxy is 6303 km/s, so SN 2001N is now about as bright as the maximum
of a normal SN Ia (vsnet-campaign-sn 139).
MKN 421 (RA = 11h04m27s, Dec = +38d12'32")
H.G. Boerst (University of Kiel), N. Goetting (University of Hamburg),
and R. Remillard,(MIT) reported; following the detection of enhanced
X-ray emission from the BL Lac object Markarian 421 with the RXTE/ASM,
observations with the Cherenkov telescopes of HEGRA show very strong
TeV activity. Above a threshold energy of 500 GeV, daily integrated
fluxes (20 minute averages) reach up to 1, 4, 2, 1.5, 2.5, and
3 times the TeV flux of the Crab Nebula in consecutive nights during
January 16-22. The ASM observations of Mkn 421 in mCrab at 2-12 keV:
44(2) over UT 2001 January 13-18; 30(3) Jan 19-20; 54(3) on Jan 21,
and 80(6) on Jan 22. The peak is the brightest X-ray flux seen
from a BL Lac object during the RXTE Mission (vsnet-campaign-blazar 128,
129, 134, vsnet-campaign-xray 60). L. Takalo and R. Rekola reported
they have taken observations on Jan. 22 in B, V and R bands and
will take some additional data (vsnet-campaign-blazar 130).
No exceedingly brightening at optical range has been observed to VSNET
(vsnet-campaign-blazar 133, 137), but observations on January 28 indicate
a possible one (vsnet-campaign-blazar 139).
QW Ser (RA = 15h26m13s.99, Dec = +08d18'03".8)
P. Schmeer reported an outburst at 13.2mag of the SU UMa-type
dwarf nova QW Ser (=TmzV46) on January 25. The most recently
observed outburst (a supermaximum) was detected by me on 2000
July 5.941 UT at mv= 12.4 (cf. vsnet-alert 5068). Prior to that one
P. Schmeer had found three other outbursts: 1999 Oct. 4 (supermaximum),
2000 Jan. 4 (normal), May 1 (normal) (vsnet-campaign 714,
vsnet-campaign-dn 415). It was faded to 13.7mag on January 26 as
reported by E. Muyllaert (vsnet-campaign-dn 418).
SX LMi (RA = 10h54m29s.93, Dec = +30d06'30".0)
As reported by M. Simonsen, the SU UMa-type dwarf nova SX LMi was
reported to be in outburst. The present outburst is a relatively
bright one, suggesting a superoutburst. The last superoutburst was
observed in 2000 March - April (cf. vsnet-alert 4492, 4496, 4499).
(vsnet-campaign 715, vsnet-campaign-dn 416).
The outburst is now continuing (vsnet-campaign-dn 419, 424).
3C 273 (RA = 12h29m6s.7, Dec = 02d03m08s)
The famous quasar 3C 273 is reported bright (12.4mag on January 1 by
H. Maehara; 12.3mag on January 25 by M. Simonsen). The object is the
brightest in recent years (vsnet-campaign-blazar 135).
BF Eri (RA = 04h39m29s.62, Dec = -04d36'10".0)
An outburst of the dwarf nova BF Eri was reported by M. Simonsen
on January 26 at 13.5mag. The last outburst was observed in 2000
November - December (vsnet-campaign-dn 417). The outburst continues
(vsnet-campaign-dn 428), and further brighter on January 28
(vsnet-campaign-dn 435).
RX J0640-24 (RA = 06h40m47s.72, Dec = -24d23'14".5)
As reported by R. Stubbings and B. Monard on January 26,
the potential SU UMa-type dwarf nova RX J0640-24 entered in an
outburst (12.4, 12.2mag). The peak brightness was comparable
to those of short outbursts observed in the past (vsnet-campaign 716).
The object faded on January as indicated by observations after January
27 (vsnet-campaign-dn 425, 433).
U Gem (RA = 07h55m05s.55, Dec = +22d00'09".2)
Serveral observers reports that U Gem is brighter than usual
quiescence on January 27-28 (13.8mag; vsnet-campaign 717,
vsnet-campaign-dn 426, 430). The slightly bright state at about 13.8
continues on January 29 (vsnet-campaign-dn 436).
OJ 287 (RA = 08h51m57s, Dec = 20d17'59")
The object is reported to be slightly fainter
(vsnet-campaign-blazar 138).
V342 Cen (RA = 11h07m15s.82, Dec = -55d57'32".7)
As reported by R. Stubbings, V342 Cen is now the first time
visually recorded in outburst (14.4mag on January 28).
R. Stubbings commented that the position agrees more with
the ROSAT ID. (11h07 15.4 -55 57' 40") and it's interesting
to see that no star is shown on the DSS images but present on
the USNO-A2.0 data, which indicates a large-amplitude dwarf
nova (amplitude exceeding 6 mag?) or other kind of CV with large
light variation (vsnet-campaign 720). The outburst continues on
January 29 (14.6mag; vsnet-campaign-dn 437).
NSV06160 (RA =13h13m12s, Dec = -36d44'.4)
As indicated by B. Monard's observations, the symbiotic variable
NSV06160, which had been in outburst since 2000 July, is reported
to be undergoing a rapid fading (11.5mag on January 28).
This fading may represent an eclipse (vsnet-campaign 721).
RZ LMi (RA = 09h51m50s.10, Dec = +34d07'29".8)
Observations by M. Simonsen on January 25 show it entered a
superoutburst, which continues now (vsnet-campaign-dn 431).
J. Kemp noticed the campaign of this object will be performed
on April 2001 (see below "Future Schedule" or, vsnet-campaign 718,
vsnet-campaign-dn 429).
RZ Psc (RA = 01h09m40s.07, Dec = +27d57'28".0)
P. Schmeer reported RZ Psc is fading to 13.2mag on January 28.
Most of the time RZ Psc stays at a maximum brightness of mv= 11.7.
Since the record of reported fadings shows all events were short,
quick follow-up observations are necessary (vsnet-campaign 723).
(continuous targets)
RX J1155.4-5641 (RA = 11h55m27s.03, Dec = -56d41'53".3)
The bright outburst continues (vsnet-campaign 712, vsnet-campaign-dn 420,
vsnet-campaign-dn 427, 432). The long outburst apparently entered
the rapid decline stage on January 29 as indicated by R. Stubbings
observation of 13.2mag (vsnet-campaign-dn 438).
AG Hya (RA = 09h50m30s.94, Dec = -23d45'03".7)
The long outburst continued (vsnet-campaign-dn 412) until
January 26 when R. Stubbings reported the magnitudes of 15.1mag
indicating it started fading (vsnet-campaign-dn 421).
SN 2001G (RA = 09h09m33s.18, Dec = +50d16'51".3)
The object seems to be keep at the maximum. M. Reszelski reported
15.2mag on January 27 (vsnet-campaign-sn 140).
V344 Ori (RA = 06h15m18.94, Dec = +15d30'59".9)
From M. Moilanen's CCD images taken on January 20, M. Uemura
estimates B-V=0.271 and V-R=0.246 of V344 Ori using Henden's sequence.
In the light curve on January 22/23 by B. Martin, we can see two
maxima whose interval is about 3 - 4 hours, and shorter time-scale
modulations are also seen (vsnet-campaign-dn 414). M. Uemura,
the Kyoto team, reported the object entered a rapid decline phase on
January 24 (vsnet-campaign 713). Observations reported to VSNET
after January 23 confirms it (vsnet-campaign-dn 423).
V445 Pup (RA = 07h37m56s.88, Dec = -25d56'59".1)
The object is relatively calm during the last week (vsnet-campaign-nova
187, 190, 191, 192, 193, 194, 195). The discussions about the helium
nova scenario for V445 Pup are seen in [vsnet-campaign-nova 188, 189].
TV Col (RA = 05h29m25s.5, Dec = -32d49'05".2)
Another very short outburst (12.8mag) occurred on January 28
as reported by R. Stubbings (vsnet-campaign-ip 37, 38).
3C 66A (RA = 02h22m39s.6, Dec = +43d02'08")
The fading continues (vsnet-campaign-blazar 136).
Delta Sco (RA = 16h00m19s.9, Dec = -22d37'17")
The observations since January 23 may indicate it is slightly
brighter (vsnet-campaign-be 81, 82).
V803 Cen (RA = 13h23m44.5s, Dec = -41d44'30".1)
The fading from the outburst was observed on January 22 by B. Monard
(vsnet-campaign-dn 413), The object seems to recover the bright state
(vsnet-campaign-dn 422), and then, marked short-term variation on
January 28 (vsnet-campaign-dn 434).
*** 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 ***
MKN 421
Comparison stars for observations: see [vsnet-campaign-blazar 131]
Sequence by B. Skiff: see [vsnet-campaign-blazar 132]
U Gem
Eclipse ephemeris: see [vsnet-campaign 717]
RX J2315.5-3049
The result will be published as IBVS No. 5023. The preprint is available
as [vsnet-preprint 14].
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-preprint/msg00014.html
[vsnet-campaign 719]
(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