Yes. Jonathan Baker from UC Berkeley has written a bibliography style package called
astronat that works with AASTeX. The package and documentation are available on the ADS website: http://ads.harvard.edu/pubs/bibtex/astronat
Please note that because AASTeX v5.x allows
\cite commands, you no longer need to run the
nat2jour.pl script on your document when preparing it for submission to the AAS journals.