Newsletter IAU WG densification of optical reference frame ========================================================== 2008 April 09 Dear WG members and interested parties, here is an update on our WG activities, as reported in responds to my recent call for contributions plus some of USNO's involvements. 1) LQAC (Jean Souchay) Notice that we submitted a paper recently concerning the compilation of all known quasars, a priori better than Veron & veron. You can find the paper in the site : ftp://syrte.obspm.fr/pub/LQAC/ ftp://syrte.obspm.fr/pub/LQAC/LQAC_2008.ascii LQAC = Large Quasar Astrometric Catalogue with 113,666 entries, including radio and optical data with cross references to 2MASS, GSC2.3 and USNO-B1 to obtain best available positions also from traditionally dedicated QSO catalogs and their poor astrometry. This is a joint project mainly between Paris Observatory and our colleagues in Rio de Janeiro, Brazil. 2) Automated Transit Circles (Jose Muinos) I send to you a report about the present status of our two CCD transit telescopes. The old CAMC in La Palma is now called CTA (automatic transit circle) by its present owner the Institute of Astrophisic of Canary (IAC). As you probably know the CUO and the IoA have abandoned the project in 2004 and they have made cession of the instrument to the IAC. This institution has left the managing of it to the ROA. At present, after a period of four months stopped due to a fail in the automation control computer, has been retake the observations to refill the zone between -15º and -30º in Dec not published in CMC14 because of bad weather and an extension of this catalogue from -30º to -40º. We have take advantage of the stop in the observations to update the observation software. About the San Fernando Automatic Meridian Circle (CAMC) in Argentina is stopped since 2007 June because a fatal fail in the CCD camera. A new camera has been purchased and will be delivery to the ROA in a month. With the observations since 2000 to 2007 June has been computed a catalogue with positions and magnitudes of stars brighter than V=16 and between -30 and 0 deg Dec this catalogue will be published next summer. Once the new camera is installed in the CMASF and calibrated will be restarted the regular observations with the instrument. The observational program has not been decided. 3) UCAC3 (Norbert Zacharias) The code development for the pixel processing was completed and all about 275,000 CCD frames run through the pipeline (about 3 weeks CPU time on 4 computers in parallel), to provide x,y, instrumental magnitudes, errors and various other parameters of all detected objects. The dark and flat processed CCD images were saved as a by-product and might become public in the future. Astrometric reductions of the StarScan plate measures (USNO Black Birch, Hamburg Zone and Lick Astrographs, plus AGK2) was completed in a collaboration with Valeri Makarov. Mean positions at mean early epochs were generated in the Cataloging Division at USNO. About 60% of all SPM raw pixel data from PMM measures (kindly provided by Stephen Levine, NOFS) were pushed through the modified StarScan reduction pipeline and x,y,mag data handed to Terry Girard (Yale University). Re-processing of the NPM detection data is in progress as well. Public release of UCAC3 is currently expected around December this year. As compared to the last couple of years big progress has finally been made with the CCD pixel data processing and work on the early catalogs for proper motions. However, many obstacles need to be taken yet and the schedule is by no means certain. 4) URAT (Norbert Zacharias) The 0.96-meter diameter primary mirror for the URAT telescope was delivered by EOST in January 2008. However, no additional funding has been identified yet to complete this telescope. The detector development for URAT made great progress with a contract being awarded to STA in March this year to build the URAT focal plane and camera. This "4-shooter" camera will consist of 4 large CCDs, each with 10,560 by 10,560 pixels of 9 micrometer square size, plus 4 smaller CCDs for guiding and focus control. The dewar will have a 300 mm aperture window which will also serves as bandpass filter (about 670 to 750 nm). Camera electronics (STA custom design) and shutter (Bonn instrument group) is part of the package. This 4-shooter camera will initially be put at the USNO Astrograph redlens to perform a new, all-sky, astrometric survey, which is called URAT phase 1, or "U-mouse". At the astrograph a single exposure will cover 27 sq.deg of sky with a resolution of 0.9 arcsec/pixel. Besides the about 25-fold increase in sky coverage per exposure as compared to the UCAC survey, the U-mouse project will also go 2 magnitudes deeper (higher quantum efficiency of detector, longer exposure times). Delivery of the camera is expected in March 2009 with begin of the new survey by mid 2009. The astrograph will be completely re-build for this program by the USNO instrument shop, taking only the redlens objective from the original Twin Astrograph and join this with the re-furbished 24-inch mount (identical to the original mount). 5) IAU 2009 Please provide input to our WG during the next 12 months in preparation for the upcoming IAU GA in 2009. If you have any item for an upcoming newsletter, please send it to me at any time. Live long and prosper! Norbert --------------------------------------