DUTCH OPEN TELESCOPE Report for NOVA ISC meeting nr. 21 February 24 2006 R.J. Rutten and F.C.M. Bettonvil DOT website: http://dot.astro.uu.nl Project management ------------------ The DOT efforts are part of the Sterrekundig Instituut Utrecht (SIU) which is part of the Department of Physics and Astronomy (DepNS) of Utrecht University (UU), formerly the Faculteit Natuur- en Sterrenkunde, now part of the collective UU Faculteit Betawetenschappen. The DOT efforts are funded until 2008 through a DepNS guarantee which includes support from NOVA. This funding covers the salaries of Bettonvil and Suetterlin, DOT exploitation including travel, IGF (DepNS workshop) effort, and funding for on-site student training. Additional funding comes from the EC for observing (OPTICON) and postgraduate education (MC/EST Utrecht-Stockholm-Oslo USO-SP graduate school). The DOT core team consists of R.J. Rutten (DOT scientist), R.H. Hammerschlag (DOT builder), F.C.M. Bettonvil (DOT project manager), and P. Suetterlin (DOT observer and data handler). C.U. Keller and AIO's J. Leenaarts and F. Snik have partial DOT interest. Postdoc J. Koza (EC/MC-EIF funding) presently completes his two years at Utrecht on DOT-oriented research. Postdoc A. Berlicki spent two months with the DOT team on EC/RTN (ESMN) funding. A.G. de Wijn succesfully defended his PhD thesis and went as postdoc to NCAR's High Altitude Observatory in Boulder, to work with Hinode data. AIO's Catherine Fischer and Nikola Vitas have started their PhD research, funded 3/4 by the USO-SP grant and the remainder by the DepNS. Six-months USO-SP trainees are Judith Palacios (nearly completed) and Radek Melich (arriving soon). G. Sliepen (UU graduate in informatics) and A.P.L. Jaegers (engineer) work through STW funding on DOT-related technology, in particular DOT-type foldaway canopies. R.J. Rutten retires formally and mandatorally this spring but continues DOT research and education. Rutten's successor Dr. Alexander Voegler started in January 2007. He is an expert in numerical solar physics and presently concentrates on radiative MHD simulations of magnetized stellar atmospheres. Progress since ISC 20 --------------------- 2006 was again a succesful year in terms of DOT observing. Since the last ISC meeting another four successful campaigns took place, three of them international. Two more DOT-students came to La Palma for two weeks training under Rutten's supervision (September). In addition, a USO-SP school on La Palma under Rutten's directorship taught DOT and SST technology, radiative ransfer, solar dynamics, image processing and Fourier processing in a mixture of classes and practicals to USO-SP graduate students and trainees. DOT technology, including its open tower and folding canopy, presently attracts much outside interest, also in connection with Antarctic astronomy projects. The large Lyot filter from Irkutsk for BaII 4554 was re-installed on the DOT after Snik's campaign (August 2006) testing it for polarimetry on the SST. During this campaign anomalously low transmission was diagnosed which is not understood. The Irkutsk designers and the DOT team have formulated tests and possible remedies that will be undertaken in the coming period. The DOT database, stored on a high-volume data server installed in the DepNS computer room and containing all high-resolution solar image sequences collected with the DOT since the autumn of 1999, grows rapidly since the installation of the high-volume 70-CPU DOT Speckle Processor on La Palma. In order to make this database easier accessible to both the scientific community and the general public it has a user-friendly graphical interface showing for every day with worthwhile data a thumbnail pictorial index of what was collected. A search engine is now under construction to assist in finding particular data while accepting selection through target specification, observing mode, time of observation, desired cadence, solar disk location, and seeing quality, and also linking to the pertinent Mees active region maps. It is planned to make the database part of the Virtual Solar Observatory. We would like to include an engine offering exemplary DOT images and movies of solar phenomena with appropriate descriptions, also targeting both scientists and the general public, but have not succeeded in procuring funding for such effort. The implementation of new cameras for the H-alpha channel with better S/N and larger field of view was started. A calibration-unit has been built to help aligning optics on the DOT without need for pointing the telescope on the Sun (which makes the instruments rather unaccessable). Rutten completed his stewardship of the EC-funded ESMN network (1998 - 2006) by co-organising a 100-participant farewell conference at Coimbra of which he presently co-edits the proceedings (to appear in ASP-CS), and by writing the final ESMN report now under scrutiny by the EC. In addition to funding postdocs Suetterlin, Tziotziou, and Berlicki (at Utrecht, plus 27 elsewhere), this grant paid most of his travels to La Palma in recent years. Meetings since ISC 20 --------------------- - Coimbra conference, October: Rutten (SOC and editor), Koza, Berlicki, Leenaarts, de Wijn, Hammerschlag, Bettonvil, Vitas, Melich - IASS/APCS conference Beijing, October: Bettonvil - ARENA Roscoff, October: Hammerschlag - CCI, NA2, OPTICON, September: Bettonvil - STW canopy technology meetings December: Halfmann, Blum (GREGOR) January: Bettonvil, Hammerschlag Milestones ---------- See "DOT publications" at http://dot.astro.uu.nl. Critical areas -------------- The DOT is run on a very tight budget. The daily observing requires the full attention of Hammerschlag, Bettonvil and Suetterlin, but so do hardware and software maintenance and upgrading. These activities will remain in strong competition this year. Although the Department's funding for the DOT guaranteed 3000 hours/year of IGF effort nominally, in recent years the actual allocation was decreased unilaterally by up to 50%. This has been and remains a major drawback in both the exploitation and technical problem solving. The DOT future beyond the beginning of 2008 remains uncertain. A major new reason to continue the DOT a few more years is the Europe-wide initiative and commitment to build a 2.5-m class "next generation" European Solar Telescope, preferably on a shorter timescale than the American Advanced Technology Solar Telescope (4-m design pending NSF support). DOT technology, the DOT as testbed for experiments, and possibly mechanical parts of the DOT itself can play an important role in the EST development and make Utrecht a key partner in this project. Another motivation for continuation beyond the beginning of 2008 is that the recently launched Japan-US-UK Hinode satellite (approximately the same aperture as the DOT) is unlikely to fulfill its intended chromospheric diagnostic capability (H-alpha tunable-filter imaging) - in which the DOT excels. Plans for the coming half year ------------------------------ Currently the DOT TAC is reviewing all international proposals for the 2007 observing season in order to schedule the 2007 DOT deployment. We expect another well-booked season with the first international campaign in March. Rutten intends to continue the Students-to-the-DOT program, as well as teach at an USO-SP summerschool in Oslo (June) and run another USO-SP school on La Palma (autumn). The total of students he supervised in projects with a large on-the-spot component (tyically 7.5 ECTS) is likely to grow to about 30 this year. Rutten also intends to complete various papers resulting from DOT-student data analyses. Spectrographic measurement of the transmission of the Irkutsk Lyot filter and re-aligning its optical stages. General maintainance before the start of the 2007 observing season. Tests with new H-alpha cameras including effective focal length modification. Further safeguarding and automation of the DOT operation. Development of a measurement and registration network of wind, temperature, pressure and seeing sensors for the measurement of canopy and open-dome characteristics (STW grant). Investigation of a proposed OPTICON proposal tool for solar telescopes. Further DOT-future deliberations including potential international partnerships and venues towards the EST.