Subsections

• OPD Instrumentation - Eucalyptus spectrograph
• Construction of an optical laboratory
• LNA databank
• Other activities
  • Observing log:
  • End of night report:
  • Observing assistance:

Support to the Observatório do Pico dos Dias (OPD)

OPD Instrumentation - Eucalyptus spectrograph

As a prototype for an Integral Field Unit (IFU) spectrograph for the SOAR telescope the construction of an instrument named Eucalyptus was completed. The purpose of this project was (1) to gain experience in handling optical fibres with a core size of around 50µ , (2) to provide a new, powerful instrument for the OPD, and (3) to qualify the technical staff of the OPD for the operation of up-to-date technology. Eucalyptus has has 512 fibers (16 x 32   microlens matrix) covering a 15" x 30"  field (0.9" per microlens) on the sky. Operating in quasi-Littrow mode the instrument furnished medium resolution (R=3000-9000) spectra in the range of 4000 Å - 10000 Å. First light occurred in the first semester of 2001. The results confirmed that thin optical fibres can indeed be used in astronomical IFUs and that the OPD staff dominates the techniques to construct such IFUs. (A.C. Oliveira, B.V. Castilho, and members of other LNA departments: C. Gneiding, F. Rodrigues, R.P. Campos)

Construction of an optical laboratory

An optical laboratory was constructed which includes an optical fibres workshop, clean room, polishing room and an optical lab to characterize fibre systems. This laboratory is almost ready to operate and will be used to build an IFU for the SOAR-Telescope. The workshop is equipped with a two especial microscopes, an ultrasonic cleaner, and a workbench with a special surface to avoid damage in optical fibres. It was made in a clean room to eliminate contamination in the fibres systems during handling, in particular during the process of glueing fibres. Thus extra carefulness is required because we intend to work with this fibres of size core around 50µ . Most dust particles have a size close to this values so the contamination can be critical. The optical laboratory includes a device to document the process of instrument construction. Moreover, it will enable us to measure the focal degradation of the fibres in the complete optical systems and the efficiency of optical systems in general. A polishing machine was developed on the basis of an old lens polishing machine and will be used to polishing fibres systems. This Laboratory will be used not only to construct the SOAR IFU, but also to support to another activities necessary to maintain the quality of the service of the ODP. (A. César de Oliveira)

LNA databank

Albert Bruch was responsible for the development and the maintenance of the archive of observational data obtained at the telescopes of the OPD (termed LNA databank hereafter). In this context the following activities were developped:

1. In order to guarantee the long-term security of the data collection a program, initiated in the previous year, to copy all data of the LNA databank, which were originally stored on magnetic media, to CDs was continued. By the end of 2001 this program was almost completed, all but a few data having been transferred to CDs.
2. A system was installed at the OPD which facilitates the archivation of the observational data. Each day the data of the previous night are automatically copied to a particular hard disk. ``Garbage'' data are deleted and the useful data are compressed. Whenever the automatic system notices that enough data of a particular telescope have been collected to fill a CD a mail is sent to the operator, advising him to acutally burn the data on CD. At the same time, the covers of the CD, containing the most important information about the data, is prepared an printed. This system substitutes the older system to copy the data to magnetic tape, reducing the human interaction to a minimum and thus requiring much less manpower and providing higher reliablility.
3. With the growth of the databank over the years, and in particular to inclusion of data from years before the first installation of the system DaBIAS on the internet which was concluded in the year 2000, searches for observations of particular objects within the databank turned out to become rather time-consuming if no restriction was imposed on the search. Therefore, the DaBIAS system was enlarged by a system of files containing for each observed object the date and the telescope at which is was observed. This system increased the speed of a search in the DaBIAS system considerably. Depending on the number of observations of a particular object, the necessary time to search for an observation could be decreased from 5 minutes to 5 seconds, improving the performance of DaBIAS significantly.
4. While the DaBIAS system (and thus the information about what has been observed at the telescopes of the OPD) is freely accessible for everyone on the internet, the data themselves are only available to people who may have a serious interest in them. In order to avoid that someone requests data who just ``plays around'' on the internet a registration system has been installed on the internet. DaBIAS permits only registered users to request data.
5. The data bank administration routine ``db_admini'' has been perfected, adapted to the new developments of the databank, and enlarged. Currently, the following functions are available within this routine:
   1. Update the DaBIAS object name files
   2. List/remove names from the DaBIAS object name files
   3. Edit data bank summary files
   4. Edit observer name list
   5. Remove a night from the data bank
   6. Change telescope attachment
   7. Update file-system for new year
   8. Registration of data bank user
   9. Display of user statistics
6. The general maintenance of the LNA databank includes daily verification of the automatic performance of the DaBIAS system, eventual corrections (in particular in consequence of disobedience by the observers of the simple rules guaranteeing the secure performance of DaBIAS!) and the search of alias names for the observed objects, using the SIMBAD data bank.
7. An article for the Boletim da Sociedade Astronômica Brasileira about the structure and the performance of the LNA databank has been prepared in order to acquaint the brazilian astronomical community with these topics and the sensitize the observers about what they can do to secure the good performance of the databank.

Other activities

Observing log:

A software system has been developped which is meant to substitute the lists of observations filled in manually by the observer at the telescope. The software reads automatically the headers of the data files created during the night and extracts all relevant information (name of object, coordinates, exposure time etc.) about each observation. Additional information, which is not part of the header contents of the observations, such as the magnitude or spectral type of the object, the width of the spectrograph slit, the seeing etc. can be added interactively by the observer. This list can be updated along the night. Finally, the observer can demand a printout of the list which is then done in a form of an easily readable table (using L^ATEX). This system is expected to reduce the work load of the observer during the night. (A. Bruch)

End of night report:

A first version of an electronic ``End of the Night'' report was developped, which will substitute the present paper version. This system transmits information about the use of the obsering night and the performance of instrumentation faster and more reliably to the OPD operations staff. A test version of the system is running with good results. (B.V. Castilho and members of other LNA departments: N. Gonçalves)

Observing assistance:

Introduction to the use of the IAG 60-cm telescope, peripherals, detector and assistance to UEFS visiting astronomers and students was provided. (M. de Oliveira-Abans)