Frequently Asked Questions (and Answers)


1. How do I contact the librarians?
see Need help? on the library start page.

2. When do I have access to the libraries?
The libraries are open 24 hours per day. Librarians are available between 9:00 a.m. and 5:30 p.m. If you want to borrow any books or other media, please don't forget to register them at the publict erminals in the libraries.


3. How do I access the library catalog?
The public user interface is at
For basic searches, key in any search terms (title words, authors' names, keywords etc.) and hit return or click on the specific search options (Title etc.) provided by the catalog.

4. Is it difficult to use the library catalog?
Not at all. The library catalog, can be used intuitively. Just point-and-click on the icons or written options you want to choose. We usually recommend to try the STANDARD SEARCHING mode, since it will search all parts of all records for the search terms you have entered. Search terms can be truncated by $ (the dollar sign) and combined by using the Boolean operators AND, OR or NOT. You can find more information in our flyer.


5. Which classification system do the ESO libraries use?
We use an internal classification system that was created when ESO was founded and has undergone only minor changes since then.The system consists of five large groups (Astronomy, Physics, Engineering, Mathematics,and Handbooks/Dictionaries). A list of all groups and subgroups is available on the start page of the library catalog

6. What will I find in the library catalog?
The library catalog includes information about books, ebooks, journals, standards, CD-ROMs, diskettes, microfiches, videos, slides, observatory publications, and all other media available in the ESO libraries. In addition, the items pertaining to the ESO Historical Archive (compiled by Prof. A. Blaauw), a collection from Prof. J.H. Oort and the Optical Library of Prof. G. Franke can be searched. ESO affiliates can access those electronic journals to which the libraries subscribe from within the library catalog by clicking on the hyperlinked Electronic Access field. Preprints and individual articles are not included in the library catalog (please refer to the sections below).


7. The book I want to borrow is not on the shelf. What now?
Most probably, the item you are looking for has been borrowed by someone else, or it may be misplaced or even be missing. In any case, please contact us, and we'll locate the book for you.

8. How do I search for published papers?
The most popular service is the ADS Abstract Service. Access to fulltexts of electronic journals can also be found on the libraries e-journals page.


9. How do I suggest to order books and other media for the ESO libraries?
For your convenience, a request form is available which can be used to suggest book purchases.

10. Can I borrow items? All items?
Books, CD-ROM, standards, and observatory publications can be borrowed. Library items can be checked out by using the self checkout form. Just login with your email address (without as user ID and password. The item ID is the bar code number on the label located on the inside cover of every book. For Garching items, this number starts with ML, followed by a year and a six-digit number (e.g., ML 1998 123456); items in the Chile libraries start with LS. If you need an item that is currently on loan to another user, contact us at Also contact us if you never borrowed any library item before. We will then set up a library user account for you.

Please note that we don't adhere to strict loan periods, but expect users to return borrowed items in case they are requested by somebody else. Library staff must have access to borrowed library items at any time.

Journals (bound or unbound) must not be borrowed. However, exceptions are possible, so if you need any volumes or issues urgently, let us know.

Please don't forget to return all library items when you are leaving ESO.


11. For how long can I keep borrowed items?
We don't oblige you to return library items after a certain loan period, so that you can keep them as long as you need them. However,we expect you to return them to the library as soon as another user needs them. Please refer also to the next item about taking borrowed items home or on a trip.

12. Can I take borrowed items home or on atrip?
No! We are pretty generous with regard to loan periods, meaning thatyou can keep items from the library as long as you need them. However,we ask you to return them quickly when another user requests them. If you go on vacations or duty trips, please leave all library items in your office so that the librarians can find them if necessary.


13. How do I return borrowed library items?
Just put those items you want to return in the library office. In Garching, you will find a RETURNS box in the library office; in Santiago, you can leave them on the librarian's desk. We will discharge them from your account and reshelf them.

14. What happens if I lose or damage a book?
Bad question! You shouldn't lose or damage books to begin with. If you do so nevertheless, Conan the Librarian will get very angry and probably will demand that you pay the book.


15. Can I request a book from another library?
Yes. We can ask for books from other libraries through interlibrary loan. Depending on which library owns the item you need, it may take a while though. But we will try to do our best to obtain it as soon as possible. Please note that not only we (the librarians) but also you (the user) must adhere to copyright regulations if you make use of interlibrary loan.

16. Can I ask for a photocopy of a journal article that is not available at ESO?
Yes, you can. As is the case with books requested through interlibrary loan (see above), we can also obtain for you photocopies of articles and conference proceedings which are not available at ESO. Again, please be aware that you must adhere to current copyright regulations.


17. How do I access electronic publications?
If you are affiliated with ESO, you have automatically access to all journals licensed by ESO, if you're within the ESO network. You can also access electronic journals from within the library catalog or through ADS Abstract Service (

18. I need an e-journal article, but the ESO Libraries do not subscribe to this journal. Can the librarians obtain the article for me?
Copyright regulations are undergoing vast changes at the moment. Many publishers and governments feel that current copyright regulations are not suitable for the digital environment, because intellectual property rights are seemingly difficult to protect. Existing copyright regulations of many countries are being amended by clauses that restrict traditional user rights. This also affects essential library functions,for instance providing users with publications via inter library loan(ILL). ILL from electronic publications can be entirely prohibited. Individual librarians and professional librarians' organizations are negotiating extensively with publishers in order to achieve more favorable usage conditions. Nevertheless, it can be possible that you need an electronic article that your librarian is not allowed to obtain for you. Of course we will do everything possible in order to get a copy of this publication from other sources (which will be possible in the majority of cases), but we feel that excluding scientists from access to (electronic) information is a serious threa tto science now and in the future and therefore would like to alert scientists to the possible damage that can be done by restrictive license agreements for electronic publications. If you are interested in this topic(and we hope you are!),please be invited to come to the library for further discussion.


19. Why does ESO not subscribe to Nature Astronomy?
The ESO Faculty decided not to subscribe for a number of reasons. (intranet)