DUTCH OPEN TELESCOPE Report for NOVA ISC meeting nr. 13 March 12, 2003 R.J. Rutten, F.C.M. Bettonvil, P. Suetterlin Overall status -------------- The "DOT science exploitation period" during 2002-2004 is funded by UU, NWO and NOVA to: - complete and exploit multi-wavelength solar speckle imaging for atmospheric tomography; - automate and safeguard DOT control to permit common-user operation. All work during the report period addressed these goals. Detail is given below. Initial photosphere + chromosphere (G band + CaII H) tomography was very successful. Four wavelength channels (blue and red continua, G band and Ca II H) are now installed. Installation of the two Lyot filters (H-alpha and BaII 4554) remains scheduled later this year. The architecture for a DOT Speckle Processor that can achieve overnight speckle processing was defined and led to a proposal to NWO Apparatuur-M. Our aim remains to "open the DOT" by exploiting the full DOT niche through frequent sharing in international multi-telescope campaigns next year, through common-user time allocation including PI-led student service during the summers. Project management ------------------ The DOT team presently consists on the solar physics side of R.J. Rutten (PI), postdocs P. Suetterlin and K. Tziotziou and AIO A.G. de Wijn, on the technical side of R.H. Hammerschlag, F.C.M. Bettonvil and D. van Tricht, with support from SIU programmer E.B.J. van der Zalm (part-time) and from the UU Faculty workshop IGF (including A. Jaegers and P.W. Hoogendoorn). The UU Faculteit Natuur- en Sterrenkunde has formally separated Utrecht solar physics into the "Solar Astronomy" research program per December 15. The program remains part of the Sterrekundig Instituut Utrecht but its financing by the Faculteit will be separate. Rutten is ad-interim program leader, awaiting the new solar physics professor. A search committee for the latter has been set up and had its first meeting. K. Tziotziou started as EC-RTN ESMN postdoc. He was a postdoc in the preceding ESMN network at Meudon and will apply expertise gained there in H-alpha inversions and interpretation at the DOT. AIO A.G. de Wijn started November 1, 2002. Another AIO, candidate identified, will start in autumn. Progress since ISC 12 --------------------- Most technical effort went into the realisation of the first four channels of the multi-wavelength imaging system, consisting of the elaborate mechanical system mount at the telescope top next to the incoming beam and the optical trains for the blue continuum, the red continuum, and Ca II H. The basic design was done before, but there was yet much design detailing required, including optimisation to suit the types of glass and the specific dimensions of the actual components. Motor-controlled filter tilters enable passband shift during observing (e.g. scanning through the extended CaII H wing). The last lens groups are mounted on slides to achieve identical magnification. The cameras are mounted on adjustable platforms for exact field alignment. The optical components were tested extensively at ASTRON. Most mechanical parts were made by IGF. The actual IGF capacity, reported as critical issue at the last ISC meeting, indeed became a time-limiting bottleneck. It was eventually solved after negotiation with the Faculteit through outsourcing some of the incomplete work shortly before the departure date. For the computer control of the filter motors etc. a new system is being set up employing PC/104 embedded PC modules. It will operate under Linux and greatly simplify control integration and maintenance (van Tricht). Work on software for a new framegrabber for the phase-diverse video autofocuser has started (van der Zalm). The IGF has upgraded the image-acquisition software. A major improvement is the resulting much faster display refresh, needed to better judge the observing conditions. The canopy opening and closing automation installed during the last period works wonderfully. It greatly reduces the operational risks and represents a major step in the safeguarding needed for frequent DOT exploitation. ASTRON is presently manufacturing the correction optics for the Ba II 4554 channel. A.G. de Wijn's graduation work on speckle code parallellization (in computational physics; he graduated also in astronomy) formed the basis for intensive speckle processing deliberations with computer experts Dr. Ir. A. van der Steen (UU) and Dr. M. van Noort (Oslo). They resulted in a sound hybrid architecture for a "DOT Speckle Processor" which will be able to process the complete 1.6 GByte data stream from all six cameras running at 30 s cadence during eight hours within the subsequent night, cleaning its disks for the next observing day. A detailed design including non-trivial heat removal was submitted as Apparatuur-M proposal to NWO (text available under "Documents" on the DOT website). It will speed up the speckle processing by two (!) orders of magnitude. We plan installation the coming winter in order to become manpower-limited rather than processing-limited in DOT observing next year. Work on DOT++ design including successful numerical feasibility simulation is described in the NOVA-2 DOT++ proposal. Major meetings -------------- Meetings - Nov 25-29: DSP architecture definition, with A. van der Steen (UU) and M. van Noort (Oslo) Observing campaigns - Dec 5 - 11, co-observations with POLIS and TESOS on the VTT, PI A. Tritschler (KIS). The DOT obtained its first tomographic G-band + Ca II H movies, of a plage region and a quiet region, respectively. The latter pair was the first to come out of the speckle reconstruction and is available on the DOT website (dot.astro.uu.nl). The seeing was only fair but even so, the Ca II H movie is of unprecedented quality. It is being analysed both by the DOT team and by colleages in the US. The plage movie may appear on the DOT website before the ISC meeting. Travel to the DOT Nov 21 - Nov 24: Hammerschlag; mainenance and CCI; Nov 29 - Dec 14: Suetterlin, Bettonvil, Hammerschlag; tests of Ca II H optics + science campaign; Feb 27 - Mar 13: Hammerschlag, Bettonvil, Jaegers, Suetterlin; basic assembly of the multi-channel system plus installation of channels 3 and 4. Milestones ---------- - DOT papers accepted by A&A and ApJ. Relations with collaborators ---------------------------- - ASTRON: optics measurements and manufacturing; - partnership accepted in two major American proposals now being formulated for NASA's 2007 SMEX opportunity; - partnership accepted in two European solar physics initiatives in FP6 context. Critical areas -------------- IGF planning and actual manpower allocation remain a concern. As reported before, the Faculteit Natuur- en Sterrenkunde has announced installation of a detailed Planning & Control Cycle, but effectuation is slow in coming and the outcome remains unclear. As before, support from the ISC may be desirable at some stage. As noted before, the smallness of the DOT team remains a critical constraint, surely to be addressed in UU solar physics professor negotiations. We hope that installation of the proposed DOT Speckle Processor (DSP) will enable removal of the looming speckle processing bottleneck. Budget ------ The main present concern is obviously the DSP funding. The total cost (NWO-M proposal) amounts to 188 kEUR. Half of the required 25% matching has been requested from SOZOU. Plans for the coming half year ----------------------------- - realisation of the H-alpha and BaII 4554 channels; - further safeguarding automation; - start of a joint project with the Kiepenheuer Institut and Ondrejov to study prominences and filaments; - more initial tomographic observing (we have four requests for campaign sharing so far); - start on H-alpha processing and inversion techniques; - DSP hardware selection, tender procurement, vendor selection. Items for specific consideration by the ISC ------------------------------------------- As before: ISC support in defending the share of IGF time allocated to the DOT in the Facultaire Planning & Control Cycle may be desirable in the coming months.