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CCD Views
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THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
Tel. 617-354-0484 Fax 617-354-0665
http://www.aavso.org
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C C D V I E W S
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Special Issue: May 5, 2002
1. Introduction to May Special Issue
2a. Special Observing Requests by JAM: XMM Campaign
2b. Special Observing Requests by JAM: RXTE Campaign
2c. Special Observing Request by JAM: UV Per
3. V4334 SGR - Sakurai's Object
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1. INTRODUCTION TO MAY SPECIAL ISSUE
Many observing campaigns are underway which should be of
special interest to CCD observers so we have issued this special
edition of CCD Views. Our next full issue will probably be
released near the end of June just prior to the Spring Meeting
of the AAVSO in Hawaii.
We have noticed that many subscribers to CCD Views are not
subscribed to the AAVSO News Flash -- an electronic publication
issued several times a week (as needed) which lists observations
of cataclysmic variables in outburst, and unusual behavior of
other variables, and announcements on nova and supernova
discoveries. We have many faint cataclysmic variables that need
monitoring and the News Flash is the best way to stay tuned to
their activity. If you don't subscribe via e-mail, be sure to
check out the web site at http://www.aavso.org/newsflash/ for
the latest in CV activity and read the back issues of CCD Views
for faint CV monitoring tips and requests.
Good observing!
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2A. SPECIAL OBSERVING REQUEST BY JAM: XMM CAMPAIGN
Our colleagues at the University of California in Santa
Barbara will be observing several dwarf novae in the next few
weeks using the X-ray Multi-Mirror (XMM) satellite and have
asked us for help in monitoring the variables optically (see
AAVSO News Flash 950). The objects and dates of observation are
as follows:
Object Start of Observation (UTC)
====== =========================
SU UMa MAY 05 17:14:54
EI UMa MAY 10 09:54:07
Please keep a close eye on these variables for as long as you
can (at least several hours, if possible) particularly on the
dates of XMM their observation. In addition, please monitor
these objects closely before and after the XMM observing runs so
that the optical light curve can be correlated with the X-ray
data.
Observing tips: Please use a CCD V filter
Report the comparison stars used in your
observations
Report the time of your observations to
4 decimals of the JD.
Charts are available at these URLs:
http://www.aavso.org/charts/UMA/SU_UMA/
http://www.aavso.org/charts/UMA/EI_UMA/
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2B. SPECIAL OBSERVING REQUEST BY JAM: RXTE CAMPAIGN
Dr. Darren Baskill of Leicester University, Leicester, UK,
will be observing the dwarf nova WW Ceti with the Rossi X-ray
Timing Explorer (RXTE) from May 10 through August 9, 2002 for a
duration of 3,000 seconds each day. He has requested the
assistance of AAVSO observers to monitor WW Cet simultaneously
with his X-ray campaign so that the optical and X-ray data may
be correlated ( see AAVSO Alert Notice 295). Dr. Baskill
provides the following description of the project:
The relationship between X-ray and optical observations varies
dramatically between dwarf novae. In U Gem, the X-ray count rate
increases during optical outburst, while observations of SS Cyg and
SU UMa (see AAVSO News Flash #772) show completely the opposite; the X-ray count rate falls during optical outburst.
This may be due to the inclination of the system - U Gem has an
inclination of 70 degrees, whereas SS Cyg and SU UMa have much
lower inclinations of 37 degrees, and 44 degrees, respectively. The
inclination of WW Cet is 54 degrees, and so it is unknown whether
it will behave like U Gem or SS Cyg.
This new data should help us understand the X-ray variability (and
the optical relationship) of dwarf novae.
Observers are urged to monitor the variable closely,
particularly during intervals when RXTE is observing WW Cet.
Observing tips: Please use CCD V filter
During RXTE observing times the frequency of
the observations should be every 5 minutes
Start observations 15 minutes before and
continue 15 minutes after the scheduled
RXTE runs
When RXTE is not actively observing WW Cet,
observe it every hour during the night
Report the comparison stars used in your
observations
Report your observations to 4 decimals of JD.
Charts for WW Cet are available at:
http://www.aavso.org/charts/standard/CET/WW_CET/
More information about this campaign, including time tables are
available at:
http://www.star.le.ac.uk/~dbl/xtewwcet.html
the JD.
Good coverage from our observers is extremely important to the
success of this observing program.
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2C. SPECIAL OBSERVING REQUEST BY JAM: 0203+56A UV PER
This dwarf nova type (SU UMa subclass) cataclysmic variable is
having one of its rare outbursts -- maybe a superoutburst --
which started on May 2 (see AAVSO News Flash 958). The last
outburst (superoutburst) recorded in the AAVSO International
Database was in Dec 2000/Jan. 2001.
The superoutbursts usually lasts about ten to fifteen days.
UV Per has interesting superoutbursts, in that it is known to
have some superoutbursts that start with a short outburst
followed by a full blown superoutburst (see the superoutburst of
Mar 1996-JD 2450150+). In addition, often a short outburst is
again seen a few days after the superoutburst reaches minimum
(see the superoutburst of Mar. 1996).
Please follow UV Per closely to see how it is going to behave this
time.
Observing tips: Observe with a CCD V filter
Search for superhumps - observe the star every
5 minutes _for as long as you can_
throughout the night, particularly
observers with good northern horizon
Report the comparison stars used
Report your observations to 4 decimal of JD.
During the last outburst Ron Zissell got an excellent set of
superhump CCD V data. We are planning to prepare a publication
of those observations together with observations (hopefully of
superhumps) of the current outburst.
Charts for UV Per are available at URL:
http://www.aavso.org/charts/PER/UV_PER/
Good Observing! --- Janet
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3. V4334 SGR - SAKURAI'S OBJECT BEHAVIOR
V4334 SGR "Sakurai's Object" is gaining much attention lately.
According to IAUC 7879 it has heated up and may be retracing its
path away from the Asymptotic Giant Branch (AGB) for the second
time. Also, it could be an analogue for mysterious V838 Mon
(IAUC 7886). A complete description of Sakurai's Object is
beyond the scope of CCD Views, so we plan to devote the June
Variable Star of the Month to it. Please stay tuned to http://www.aavso.org/vsotm/
for more detail.
In the meantime, please monitor the object closely. The last
positive AAVSO observation was 15.0 by Steve O' Connor (OCN) on
October 25, 1998! CCD observers should monitor V4334 Sgr over
the next few years at least once a week, whenever possible. If
any significant activity is detected increase your monitoring
interval and notify the AAVSO. An observation of V4334 Sgr was
made by Alan Gilmore and Pam Kilmartin of St. John's Observatory
in New Zealand at the request of the AAVSO. Their unfiltered
image has V4334 Sgr at around magnitude 16.3, but the star is
quite red so if you cannot image it in V try using an R filter.
New charts have been made using photometry from A. Henden and
a sequence from B. Sumner. F and G-scale charts were created
because it is a challenging and crowded field. The charts can be
downloaded at this URL:
http://www.aavso.org/charts/SGR/V4334_SGR/
Here is color data from Henden for the new F and G charts:
Comp V Err B-V Err
125 12.545 0.006 1.638 0.004
134 13.410 0.029 0.826 0.011
139 13.928 0.019 1.710 0.013
143 14.286 0.011 1.224 0.013
145 14.528 0.006 0.938 0.022
149 14.886 0.000 1.403 0.002
152 15.222 0.036 1.271 0.012
156 15.607 0.000 0.977 0.012
160 15.985 0.056 1.164 0.004
The full sequence file is available at:
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/sumner/v4334sgr.seq
Note: There is a close companion to this star, located 10 arcsec
west- northwest. This companion has a magnitude of V=17.033 and
B-V=2.303.
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CCD Views is published bimonthly and when circumstances
warrant via e-mail. An archive is available at
http://www.aavso.org/ccdviews/ . Please send comments and
suggestions to aaronp@aavso.org.
To receive CCD Views via e-mail send a message to
majordomo@aavso.org with "subscribe ccdviews" in the body of the
e-mail. To unsubscribe, place "unsubscribe ccdviews" in the
e-mail.
The AAVSO has many free online publications including
"Eyepiece Views", a similar newsletter intended for visual
observers. To learn more and subscribe visit:
http://www.aavso.org/mailinglists.stm
Good observing!
Aaron Price, AAVSO Technical Assistant (PAH)
Gary Walker, Chairman of the AAVSO CCD Committee (WGR)
Copyright 2002, American Association of Variable Star Observers
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THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
Tel. 617-354-0484 Fax 617-354-0665
http://www.aavso.org
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