Unlike some disciplines, there is no standard citation style for astronomy. We recommend ProQuest Refworks as a complete citation management program (more info in the box below)
Some quick citation builders include:
ProQuest RefWorks is a citation management tool that helps researchers gather, manage, store and share information, as well as generate citations and bibliographies in a wide variety of styles. Extensive tutorials are available. The Write-N-Cite plugin allows you to cite sources while creating a paper in either Word or Google Docs, automatically building your cited references list as you write.