Behind the WHERE is a logical expression; these are similar to other languages as well, with operators AND, OR, and NOT.
SELECT name FROM rave.dr3 WHERE obsDate>'2005-02-02' AND imag<12 AND ABS(rv)>100
As before, select the absolute magnitude and the common name for the 20 stars with the greatest visual magnitude, but this time from the table fk6.fk6join. This will fail for reasons that should tell you something about the value of Bayesian statistics. Make the query work.