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CCD Views #318

                             C C D   V I E W S   #318
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                                 April 1, 2004
 
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1. Introduction
 
  Dr. Janet Mattei (1943 - 2004) was a true friend of CCD variable star astronomy. From the beginning of the CCD revolution she recognized the impact it would have on amateur observing. With Gary Walker, she helped organize one of the first amateur CCD observing workshops back in 1991, before most of us had even a dream of owning a CCD. She was constantly looking for funding so that the AAVSO could sponsor CCD equipment for our observers. She secured
funding to loan complete CCD systems to observers in Finland, Hungary, New Zealand and Australia to expand GRB network coverage.  She also funded the distribution of photometric filters to observers all over the world (CCD Views Vol. 2 No. 4) and worked with Arne Henden to coordinate the Precision CCD Photometry Workshop in 2001.
  This electronic version of CCD Views is a direct result of Janet's initiative. One day she wanted to discuss how we could help energize our CCD observers and take better advantage of their capabilities. At the time, Gary Walker was editing the original print version of CCD Views. The three of us brainstormed and decided to make it an electronic publication, meaning it could come out more often and be more responsive to our needs.
  Janet offered so much to everyone she ever worked with. CCD Observing is but one of those areas yet it illustrates well her gift of vision. She will be missed.
 
 Aaron Price (PAH), AAVSO HQ, on behalf of
Gary Walker (WGR), CCD Committee Chairperson.
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2. INTENSIVE BZ UMA 24-HOUR CAMPAIGN
 
In late February, BZ UMa (08:53:44.14 +57:48:41.1 - J2000) was visually observed in outburst by Mike Simonsen (SXN). Observers were notified via MyNewsFlash within minutes if they subscribed to the SNOBS (Significant or Noteworthy OutBurstS) list and the rest were notified via an AAVSO Special MyNewsFlash notice hours later when confirmation came in from Tonny Vanmunster (VMT). 4,270 CCD observations were made by AAVSO observers over four nights. We have analyzed that data and submitted an IBVS manuscript on the results. Responses from the IBVS editors are pending. In the meantime, a draft copy can be read here: [link removed]
 
This project highlighted two important things. First, the problems caused by gaps in the coverage. Visit the URL below to see the light curve and the gaps in it: [link removed]
 
Second, it highlighted our lack of understanding of the BZ UMa system. BZ UMa shows some signs of belonging to the UGSU subclass of dwarf novae(1). Its orbital period, mass ratio, outburst amplitude and frequency all suggest it is an UGSU. However, its outbursts do not show superhumps as they should, and it is a bright X-Ray source with abnormally strong Balmer emission lines and other peculiarities in its spectra. BZ UMa could be an intermediate polar (IP) or could be in a class of its own. Our analysis of the data from the February outburst shows signs of activity that are usually associated with IPs. It also has some tantalizing hints of other periodicities that could be very interesting, however the statistical significance of the signal is too weak believe on its own.
 
In an effort to shed more light on this system we are coordinating an intensive observing campaign of BZ UMa at quiescence. We would like to get as many observations as possible during this period to try and create a precise 24-hour light curve with as few gaps as possible.
 
We are targeting the evenings of April 19th - April 20 (UTD) as our primary day and April 17th - 18th (UTD) as a preliminary day. If you can only do one evening, choose April 19th-20th because we have time that evening on a professional Mauna Kea telescope to help fill in the Pacific gap. We realize that it is a Monday and some of our observers can not observe all night. However, please try to observe both days. This allows us to look for variations of a longer timescale and gives us some extra coverage. Note that all times are UT. We may setup a chat room for observers to hang out in during these long runs.
 
Basically what we need is for you to observe from your local dusk until dawn on the nights of April 17th and 19th.
 
We have two professional observatories who will help if weather permits. Arne Henden at the US Naval Observatory in Flagstaff and Karen Meech (University of Hawaii) who will be able to observe from Mauna Kea.
 
BTW, we need more coverage in Asia and the Pacific. If you have any friends in the area with a CCD please forward this to them!
 
BZ UMa at quiescence is quite faint, varying between V=16-17. We need integrations to be as short as possible because some of the flaring and periodicity we are looking for is on very short time scales (minutes). So we're calling for UNFILTERED observations. If you have a small aperture, consider binning your pixels if your seeing allows you to do that without taking a significant hit in precision.
 
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If you think you can participate please e-mail aaronp@aavso.org with which of the two days (17th and/or 19th) are available to you and your timezone. A list of participants and their location will be kept on the web site (see below for URL).
 
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A CCD Views Special Edition will be issued no later than 00 UT Friday, April 16th with the exact campaign times.
 
In the next two weeks please begin making observations of BZ UMa with your system. Use this time to find the best combination of exposure time and accuracy. In general, aim for 0.02 mag precision. But if you cannot reach that without taking a very long exposure then we can do with less precision. Test your system to determine the best you can do. If you have questions please e-mail your results to the aavso-photometry discussion group for advice. German-Equatorial users make note of BZ UMa's transit time at your location so you can keep the "flip-gap" as small as possible.
 
Arne Henden has calibrated this field. His data is plotted on the AAVSO f-scale charts at this URL: [link removed - all charts can be found at http://www.aavso.org/vsp]
 
Use any comparison star and check star that you see on the chart. The 131 is a good color match. Some of them have close companions so be careful to keep stars out of your annuli.
 
Please upload your data to the AAVSO for these snapshot sessions. They will be useful in establishing a baseline of activity for BZ UMa before the campaign begins.
 
In a two-hour unfiltered observing run on March 20, Bruce Gary (GBL) detected variations of up to 0.3 mag on a time scale of around an hour. Do not expect to find these variations in your data but be prepared for *any* kind of variation or oscillation.
 
A To-Do Checklist:
1. Send an e-mail to aaronp@aavso.org with your timezone if you think you can participate.
2. Practice taking at least 1 BZ UMa observation each time you are observing up until April 17 (UTD).
3. On at least one night, spend some time on BZ UMa taking unfiltered exposures and finding the best way to get precision photometry with as short of exposures as possible.
4. Stock up on coffee, tea, pizza, etc and be prepared to observe April 17 and April 19 (UTD).
 
As we analyze the data we will keep anyone who participated in the campaign updated. Observers who get more than an hour of data with SNR>40 during the campaign or who otherwise provide significant help will be coauthors on any paper we publish.
 
A web page for this campaign will be maintained at: [link removed]
 
Public discussion will take place on aavso-photometry discussion group:
 
1 - Visit our February, 2000 Variable Star of the Month for more information about UGSU dwarf novae:
 
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3. INTEGRAL BLAZAR OBSERVING REQUEST - APRIL 2-6
 
Luisa Ostorero at the University of Heidelberg (Landessternwarte Heidelberg) is requesting optical observations of the blazar S5 0716+71 for correlation with an INTEGRAL Target of Opportunity Observing (TOO) run scheduled for April 2-6.
 
S5 0716+71 is a blazar that reached historical brightness levels this week (Rc=12-13 with rapid variability). As a result, RXTE observations were recently approved and now observations with ESA's INTEGRAL satellite are planned.
 
Observers with a filter wheel are requested to perform B-V-R-I observations at the beginning and end of their observing run. In the middle B-R-I sequences should be taken for as long as possible.
 
Observers without a filter wheen should observe with an Rc filter.
 
Runs should be held from now until April 7 (UTD). Additionally, please add S5 0716+71 to your regular monitoring program.
 
Please report your observations to the AAVSO as soon as possible and include an Err: estimate. Charts are available at this URL:
 
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4. UV PER CAMPAIGN PUBLICATION
 
Thanks to the 13 CCD observers (and 6 visual) who helped out with the 2003 superoutburst of UV Per.
 
We received 11,545 CCD observations providing excellent coverage over about 10 days. A superhump period (95.92 +/- 0.006 minutes) slightly different than the previously published period (95.63 +/- 0.05 minutes from Udalski, 1992) was detected along with a change in the period that had been previously undetected. We were especially pleased with the number of observations submitted with an uncertainty (Err:). The quality of this data allowed us to publish the observations as IBVS #5488 with each observer as a coauthor. The paper is available at this URL: [link removed]
 
The next superoutburst of UV Per is predicted to be between July 20, 2005 and April 14, 2006. The 14 CCD observers who make up the UV Per Hall of Fame are:
 
Lew Cook
Tonny Vanmunster
Bruce Gary
Dave Messier
David Boyd
Arto Oksanen
Gary Billings
Keith Graham
Bill Goff
Doug West
Patrick Schmeer
Arne Henden
Ron Zissell
Ron Royer
 
The 6 visual observers who helped by detecting the outburst or the period of post-superoutburst brightening are:
 
Eddy Muyllaert
Bill Anderson
Glenn Chaple
Tracy Scott
Gary Poyner
Hazel McGee
 
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5. GRB AFTERGLOW ACTIVITY REPORT
 
This report will be the beginning of regular reports on High Energy Network observations of possible GRB localizations to be included in each issue of CCD Views. The following observations were made by network members since the last issue of CCD Views.
 
GRB040228: Donn Starkey (SDB - USA) observed the field between 3 and 3.5 hours after the detection and did not detect an afterglow. No afterglow was reported by GCN.
 
GRB031220: Arto Oksanen (OAR - Finland) and Nyrola Observatory observed the field beginning around 14 hours after the detection and did not detect an afterglow. Chandra observed this field and reported a number of previously unknown X-ray sources. Optical counterparts for a few of them were observed by large professional telescopes but whether any of them were the actual afterglow has not been established.
 
GRB040319: Diego Rodriguez (RZD - Spain) observed this field quickly but the spacecraft localization turned out to be incorrect.
 
Thanks to Donn, Arto and Diego for keeping up the watch!
 
Remember GRB observations must be reported through this web page: [link removed]
 
Quality GRB localizations have been few and far between the past few months. If you are feeling rusty, go over your observing strategies and do some practice runs. When the next big one comes through those who are well practiced will be most likely to be successful.
 
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6. GXC - LINUX/UNIX SOFTWARE FOR OBSERVATION AUTOMATION AND DATA REDUCTION
 
By Radu Corlan (CXR)
 
Over the last year or so I've been developing gxc, a program that automates observations and VS data reductions. It started with cx, a program i made to control my home-made ccd camera. (http://astro.corlan.net/cpx3m/index.html).
 
As the telescope I use doesn't point accurately enough to be able to make observations unattended, I've added a field-matching algorithm that can make pointing corrections by comparing the positions of stars extracted from a test frame to the GSC. It is now possible to obtain frames from hundreds of different fields in a fully automatic mode.
 
Identifying stars is also the most tedious step in data reduction. With the field-matching algorithm, GCX can astrometrically calibrate a frame against the GSC or some other catalog starting from an approximate position and scale, such as the coordinates of the target and the focal length of the telescope.
 
Once the frame is astrometrically calibrated, the program can do aperture photometry on selected stars. To automate the process, position standards and photometric standards are grouped in a "recipe" file, which can be thought as the electronic equivalent of an aavso chart.
 
The recipe file is 'run' on the data frame, and the program will automatically identify and measure the stars in the recipe file, and output a report. A relatively complex error model generates error figures for all measurements. I've checked the error model against time-series measurement results, and it has proven to be quite accurate.
 
The program was developed on Linux, but can probably easily be ported to other UNIX systems that support the gtk-1.2 library. GCX can be run as a GUI program, performing all the operations step-by-step, or in batch mode - so that it can be included in a higher-level reduction script.
 
The project home page is:
 
It is also listed on freshmeat at:
 
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7. NEW CCD BATCH UPLOAD FORMATS
 
The CCD Batch Upload Tool has been upgraded to support the Center For Backyard Astrophysics (CBA) and MaximDL data formats. In addition, the Default 2 column format now supports an optional third column consisting of the error/uncertainty term you derived for the observation.
 
The tool can be accessed by logging into your WebObs account. More information is here:
 
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8. CCD Observing Manual Update
 
The AAVSO CCD Observing Manual is an online manual for CCD observing aimed at the beginning to intermediate observer.
 
 
The entire manual has been inspected and updated where appropriate. Many links were updated or added and some grammar improved. The section on CCD Error underwent some further clarification and a new section on SNR was added along with a discussion of annuli. In addition, the new High Energy Network projects were added along with discussion about MyNewsFlash and the new Photometry Discussion Group. In particular you may want to pay attention to the discussion on SNR in the Photometry/Error section.
 
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9. CCD POINTS
 
The following totals are for November, 2003 (last issue of CCD Views) - March 1, 2004.
 
REMINDER: CCD Points are *not* an official AAVSO report and carry no weight at HQ. They are provided purely for fun and to start barroom brawls at AAVSO meetings.
 
Points Obs. Observer
22564 11348 COO COOK, LEWIS M. (CONCORD,CA,USA)
18155 7177 VMT VANMUNSTER, TONNY (B-3401 LANDEN,BELGIUM)
13005 3897 JM JAMES, ROBERT A. (LAS CRUCES,NM,USA)
11768 2939 MXD MESSIER, DAVID (LISBON,CT,USA)
6533 1397 BDG BOYD, DAVID (OXON OX12 9TX,ENGLAND)
6227 4719 NLX NELSON, PETER ROBERT (VICTORIA 3820,AUSTRALIA)
5054 1323 OAR OKSANEN, ARTO (FIN-40950 MUURAME,FINLAND)
3917 490 CXR CORLAN, RADU (71206 BUCHAREST 1,ROMANIA)
3871 477 CUA CORLAN, ALEXANDRU (71206 BUCHAREST 1,ROMANIA)
3806 992 MDW MACDONALD II, WALTER J. (WINCHESTER, ONTARIO K0C 2K0,CANADA)
3215 631 GKA GRAHAM, KEITH A. (MANHATTEN,IL,USA)
3201 3479 RIX RICHARDS, THOMAS JOSEPH (ELTHAM, VICTORIA 3095,AUSTRALIA)
2772 505 GBL GARY, BRUCE L. (HEREFORD,AZ,USA)
2715 493 BGW BILLINGS, GARY W. (CALGARY ALBERTA T2L0X7,CANADA)
2424 613 SDB STARKEY, DONN RAY (AUBURN,IN,USA)
1854 414 GFB GOFF, WILLIAM (SUTTER CREEK,CA,USA)
1485 356 MMU MUNKACSY, MARK J. (PORTSMOUTH,RI,USA)
1478 300 RSE ROBINSON, STEPHEN E. (ROCKVILLE,MD,USA)
1156 293 WJD WEST, JERRY DOUG (MULVANE,KS,USA)
1143 212 BKL BLACKWELL, JOHN A. (NORTHWOOD,NH,USA)
1118 196 AWJ AQUINO, WILLIAM J. (NIAGARA FALLS,NY,USA)
844 168 WGR WALKER, GARY (SHERBORN,MA,USA)
816 115 BIW BUTTERWORTH, NEIL DOUGLAS (MT. LOUISA, QUEENSLAND 4814,AUSTRALIA)
683 231 WDZ WELLS, DON (MISSOURI CITY,TX,USA)
646 339 PPK PAAKKONEN, PERTTI (FIN-80160 JOENSUU,FINLAND)
472 47 DRG DIETHELM, ROGER (CH-4118 RODERSDORF,SWITZERLAND)
447 181 MTK MICHALIK, TOM (LYNCHBURG,VA,USA)
434 69 MXM MIFSUD, MARTIN (PIETA,MALTA EUROPE MSD10)
432 48 CJS CASE, JAMES A. (KANSAS CITY,MO,USA)
373 43 RZD RODRIGUEZ, DIEGO (28400 VILLALBA, MADRID,SPAIN)
321 108 VST VALENTINI, STEFANO (CRESPADORO,ITALY)
303 72 DIL DILLON, WILLIAM G. (MISSOURI CITY,TX,USA)
273 29 BOA BRUNO, ALAIN (F-35530 NOYAL SUR VILAINE,FRANCE)
269 77 RR ROYER, RONALD E. (SPRINGVILLE,CA,USA)
267 27 ARJ ARNOLD, JAMES E. (HUNTSVILLE,AL,USA)
244 97 NMI NICHOLAS, MICHAEL (GLENDALE,AZ,USA)
240 32 CDV CORNELL, DAVID (ELSAH,IL,USA)
239 24 MTK MICHALIK, TOM (LYNCHBURG,VA,USA)
223 42 HBD HEATHCOTE, BERNARD DAVID (VICTORIA,AUSTRALIA)
209 18 DHN DIEDERICH, HANS G. (D-64287 DARMSTADT,GERMANY)
195 67 RMU RODRIGUEZ MARCO, MIGUEL (28003-MADRID,SPAIN)
112 <10 WRX WILLIAMS, ROGER G. (KALAMAZOO,MI,USA)
109 20 MMG MARTINENGO, MAURIZIO (10060 CANTALUPA (TURIN),ITALY)
96 12 KZX KERESZTY, ZSOLT (MISKOLC,HUNGARY)
87 <10 CTX CRAWFORD, TIMOTHY R. (ARCH CAPE,OR,USA)
85 <10 WJC WOJCIK, JAN (POTSDAM,NY,USA)
82 <10 GMZ GRAZIANI, MAURO (FUSIGNANO 48010 (RA),ITALY)
71 <10 HDF HOHMAN, DENNIS G. (ORCHARD PARK,NY,USA)
68 <10 CHG CHANTEGROS, HERVE (,FRANCE)
54 <10 SDY SCHARNHORST, DANNY (99084 ERFURT,GERMANY)
54 22 ASAS3 ALL SKY AUTOMATED SURVEY 3, THE (LAS CAMPANAS, LA SERENA,CHILE)
49 13 KKG KING, KERRIE (JOHNSON CITY,TN,USA)
42 <10 CDV CORNELL, DAVID (ELSAH,IL,USA)
39 <10 CLF COHEN, LOUIS (CAMBRIDGE,MA,USA)
29 13 LVY LEVY, DAVID H. (VAIL,AZ,USA)
25 <10 HBB HARRIS, BARBARA (NEW SMYRNA BEACH,FL,USA)
24 <10 BJS BEDIENT, JAMES R. (HONOLULU,HI,USA)
23 <10 FMG FUGMAN, GARY C. (LYONS,NE,USA)
22 <10 SPK SCHMEER, PATRICK (D-66132 SAARBRUECKEN-BISCHMISHEIM,GERMANY)
17 <10 HTY HAGER, TIMOTHY (NEW MILFORD,CT,USA)
13 <10 HPR HARPER, CHRISTOPHER TOWNSEND (EXETER,NH,USA)
12 <10 PAH PRICE, AARON (WATERTOWN,MA,USA)
11 <10 GRL GRANSLO, BJORN H. (,NORWAY)
11 <10 SAH SAMOLYK, GERARD (GREENFIELD,WI,USA)
11 <10 TPE TIKKANEN, PETRI (FI-40320 JYVASKYLA,FINLAND)
 
A description of the CCD Points algorithm is available in CCD Views #316.
 
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An archive of "CCD Views" is available at http://www.aavso.org/ccd-views.
 
An archive of "Eyepiece Views," a similar newsletter intended for visual observers, is available at http://www.aavso.org/eyepiece-views.
 
Good observing!
 
Aaron Price, AAVSO Technical Assistant (PAH)
Gary Walker, Chairman of the AAVSO CCD Committee (WGR)
 
Copyright 2004, American Association of Variable Star Observers
Keywords:
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484