The Standard Star Newsletter #34 CONTENTS: Editorial....................................................p. 1 Note from the Working Group Chair, Chris Corbally............p. 1 Abstracts of Papers (Smith & Tucker, Sterken, Straizys et al. x2, Zdanavicius & Zdanavicius) ................................p. 2 Websites of Interest.........................................p. 3 Meetings ...................................................p. 4 ______________________________ From the editor The International Astronomical Union General Assembly will meet this coming July in Sydney Aus- tralia, and there are a number of associated events of interest to the readership of this newsletter. The first is the meeting of Commission #45 on Stellar Classification on the morning (9:00 - 10:30am) of Tuesday July 15. Part of that meeting will be taken up with commission business, but the re- mainder will be devoted to science. For more information, contact Tom Lloyd-Evans, at thhle@st- andrews.ac.uk. In addition, as you can see from the message below, the Working Group on Standard Stars will be meeting on Thursday 17 July. I have listed under the "Meetings" heading a number of other associated meetings that are of special interest to the readership. See you in Sydney! ____________________________________________ A Note From the Chair International Astronomical Union Working Group on Standard Stars (WGSS) The IAU General Assembly, with its satellite symposia and joint discussions and special sessions, is approaching quite rapidly. The deadline for early registration is 30 April, and I hope that you will be one of those who can come to Sydney. Why? Because our time together at the IAU-GA is about the only formal meeting that we have as a Working Group. This meeting gives a real boost to our common goal, the maintenance and proper use of good standards. In between IAU-GAs this Newsletter does a fine job in promoting that goal, but there is nothing quite like talking to each other about experiences and problems and plans in the realm of stellar standards. We have a time and place for our WGSS session at the IAU-GA. It is Thursday, 17 July, last session (1600-1730) in room PM2. I look forward to seeing many of you there. Meanwhile, do advise me of any contribution you would like to make to our meeting together or a suggestion for its structure. I am sure that your planning for the IAU-GA is taking into account the wonderful sightseeing oppor- tunities of the Australian continent, but don't neglect looking into the associated conferences. For instance, the IAU Colloquium, 6-11 July, in Christchurch, New Zealand, on Variable Stars in the Local Group, looks well planned and very interesting, besides providing a chance to visit the country where The Lord of the Rings was filmed. With my best wishes for enjoyable and profitable travels, Chris Corbally ccorbally@as.arizona.edu ___________________ Abstracts The u'g'r'i'z' Standard-Star System J. A. Smith1, D. L. Tucker2, et al. 1 University of Wyoming, Dept. of Physics & Astronomy, Laramie, WY 82070 2 Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL 60510 We present the 158 standard stars that define the u'g'r'i'z' photometric system. These stars form the basis for the photometric calibrations of the Sloan Digital Sky Survey. The defining instrument system and filters, the observing process, the reduction techniques, and the software used to create the stellar network are all described. We briefly discuss the history of the star selection process, the derivation of a set of transformation equations for the U BV RcIc system, and plans for future work. Appeared in 2002, AJ, 123, 2121 For preprints, contact jasman@nis.lanl.gov On Luminous White Standards C. Sterken University of Brussels (VUB), Pleinlaan 2, 1050 Brussels, Belgium This paper reviews the definition of the luminous S Doradus variables and discusses some aspects of the photometric variability of S Doradus stars, especially HD 160529, an extreme, variable, A supergiant which introduced the author to this field. The problems of photometric standardization, especially in the environment of the decommissioning of small telescopes, which are the main instruments used in variable star study, are explored. The need for a "Luminous White Standard" is put forward, tongue in cheek, by the author, who then thanks Kees de Jager for his luminous guidance over the decades. Appeared in Journal of Astronomical Data, 8, 2002 For reprints, contact csterken@vub.ac.be Photometric Investigation of the Galaxy in the Direction of Serpens Cauda. A Catalog of Extinctions and Distances V. Straizys1, S. Bartasiut _e1;2 and K. Cernis1 1 Institute of Theoretical Physics and Astronomy, Vilnius University, Gostauto 12, Vilnius 2600, Lithuania 2 Astronomical Observatory of Vilnius University, Ciurlionio 29, Vilnius 2009, Lithuania A catalog of spectral types, color excesses, interstellar extinctions and distances of 402 stars located in the Serpens Cauda dark cloud complex and the new results of photoelectric photometry in the Vilnius system of 56 fainter stars in the same area are presented. Accepted by Baltic Astronomy, vol. 11, No. 4, p. 417, 2002 For preprints, contact straizys@itpa.lt Interstellar Extinction in the Direction of the Aquila Rift V. Straizys1, K. Cernis1 and S. Bartasiute1;2 1 Institute of Theoretical Physics and Astronomy, Vilnius University, Gostauto 12, Vilnius 2600, Lithuania 2 Astronomical Observatory of the Vilnius University, Ciurlionio 29, Vilnius 2009, Lithuania Distance dependence of interstellar extinction in the direction of the Aquila Rift is investigated using 473 stars observed in the Vilnius photometric system. The front edge of the dark clouds in the area is found to be at 22555 pc and the thickness of the cloud system is about 80 pc. The maximum extinction AV in the clouds is close to 3.0 mag. Two stars with larger extinction are found and discussed. Since the new distance of the clouds is larger than previously accepted, the cloud complex mass should be increased up to 2.7x105M which is close to the virial mass estimated from the CO velocity dispersion. Additional arguments are given in favour of the genetic relation between the Serpens and the Scorpio-Ophiuchus dark clouds. Submitted to Astronomy and Astrophysics For preprints, contact straizys@itpa.lt Interstellar Extinction along the Camelopardalis and Perseus Border J. Zdanavicius & K. Zdanavicius Institute of Theoretical Physics and Astronomy, Vilnius University, Gostauto 12, Vilnius 2600, Lithuania Interstellar extinction in a ~100 sq. degree area near the Camelopardalis and Perseus border is investigated. The study is based on the results of photoelectric photometry of 309 stars in the seven- color Vilnius photometric system published earlier (Zdanavicius and Zdanavicius 2002). The nearest stars with the Hipparcos parallaxes show that the extinction starts to grow at a distance of about 130 pc. At a distance of 1 kpc the extinction AV is between 1.1 and 2.3 mag. At larger distances the extinction determination is affected by the limiting magnitude effect. At distances >1.5 kpc we have found a number of stars with extinctions between 2 and 4 mag. Accepted by Baltic Astronomy, vol. 11, no. 4, p. 441, 2002 For preprints, contact justas@itpa.lt _____________________________________ Websites of Interest The SOFA database, which has been mentioned before in these pages, is well worth checking on a periodic basis. This website (http://edradour.astro.utoledo.edu/cgi-bin/wrap/anatoly/SOFA/) con- tinues to expand and is now definitely the place to turn when you need data on standard stars. Check out the Spectroscopic Virtual Observatory site (http://www.spectraheritage.org/) maintained by Elizabeth Griffin. This site is dedicated to digitizing and archiving spectroscopic data on photo- graphic plates. Out of idle curiousity, I entered the phrase "Standard Star" into the Google search engine and came up with nearly 1,460,000 entries. Browsing through the first dozen or so pages revealed that many of these entries do have an astronomical connection, although around page 28, one does begin to run into entries such as "Standard & Poors Stars Mutual Fund"and much later, scraping the bottom of the Google barrel, things like "Hollywood Stars in the Evening Standard". However, this exercise was not a complete waste of time; here are some of the gems I came up with: "Selected UBVRI Photometric Standard Stars from Landolt 1992, AJ, 104, 340", a very con- venient listing at http://www.noao.edu/wiyn/obsprog/images/tableA.html, a similarly useful set of links on the Lick Observatory webpage: http://mthamilton.ucolick.org/techdocs/standards/ and a very nice listing of (mostly) MK Standard stars observed by IUE, with links to the actual spectra http://hypatia.gsfc.nasa.gov/iue/stds.html. Send me the URLs of your favorite Standard Star or related sites and I will feature them in this section in the next newsletter. ___________________ Meetings IAU Coloquium 193: Variable Stars in the Local Group Dates: 6 - 11 July, 2003 Location: Christchurch, New Zealand Program: The conference will cover the following major topics: o What variable stars tell us about the Local Group o Variable stars as tracers of different stellar populations (including Galactic globular clusters, LMC/SMC clusters and Local Group galaxies) o Early type stars: B, A and F pulsators o Binary stars and pulsation o Red Giants, Miras, post-AGB stars and proto-planetary nebulae o Chemical composition of variable stars o New theoretical developments in stellar pulsation/variability o Evolutionary and pulsation properties of variable stars o Our future in space Contact email: iau193@cont.canterbury.ac.nz See http://www3.vuw.ac.nz/scps/IAU193/ for more information. IAU Symposium 219: Stars as Suns - Activity, Evolution and Planets Dates: 21 - 26 July, 2003 Location: Sydney, Australia Program: This joint solar and stellar symposium will address solar/stellar magnetic activity; coronal heating and structures in single and binary stars; atmospheric abundance anomalies; flares and transient events; winds and mass loss; and the characteristics of cool stars hosting planets. Contact person: A.O. Benz, benz@astro.phys.ethz.ch See http://cfa-www.harvard.edu/sym219/home.html for more information IAU Working Group on Ap and Related Stars Date: 16 July, 2003 Location: Sydney, Australia Program: A full day meeting of the IAU Working Group on Ap and Related Stars has been scheduled during the IAU General Assembly in Sydney. The first two hours of this meeting will be devoted to a business meeting of the SOC; the remainder will be devoted to a scientific meeting with oral presentations of about 15 minutes each. A short abstract may be submitted to the chair of the working group at weiss@astro.univie.ac.at. The deadline for submission is April 30. IAU Working Group on Standard Stars Date: 4:00 - 5:30pm, 17 July, 2003 Location: Sydney, Australia, room PM2, conference center Program: See "A Note from the Chair" on page 1 of this newsletter. Contact person: Chris Corbally, corbally@as.arizona.edu Stellar Populations Date: 6 - 10 October, 2003 Location: Garching, Germany Program: This meeting will be devoted to the properties, applications and study of stellar populations. Registration deadline is June 30, 2003 Contact Person: Stephane Charlot, stelpops@mpa-garching.mpg.de See http://www.mpa-garching.mpg.de/ stelpops/ for more information Contributions to the next Newsletter, due out in October 2003, will be welcomed at any time by grayro@appstate.edu.