\begin{thebibliography}{}
\bibitem[key]{label}bibliography entry
(Walnut Creek)(1995).ISO/macros/latex209/contrib/astron/astdoc.tex/img5.png)
\end{thebibliography}
The style astron.bst causes BibTeX to create a bibliography file which looks like:
The key is formatted from the author and year entries in the bibliographic database. It looks like:\begin{thebibliography}{}\bibitem[key]{label}bibliography entry\end{thebibliography}
{Author}{year}.
The bibliography entry is formatted from the required and optional information in the fields of an entry, like author, year, title, volume, pages, et cetera. According to the definitions in astron.bst, BibTeX takes care of the typographical intricacies of the bibliography entry, such as punctuation, italics for journal names and booktitles, boldface for journal volumes, etc.
As an example, here is what astron.bst made BibTeX make of
\cite{lamport} in this document:
\bibitem[\protect\astroncite{Lamport}{1986}]{lamport}
Lamport, L.: 1986,
\newblock {\em LaTeX, A Document Preparation System},
\newblock Addison-Wesley, Reading, Massachusetts