Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_98 (right_ascension___j2000__ VARCHAR, constellation VARCHAR, ngc_number VARCHAR)

### Question ###
Which Right ascension (J2000) has a Constellation of mensa, and an NGC number larger than 2171?

### Accurate SQL ###

SELECT right_ascension___j2000__ FROM table_name_98 WHERE constellation = "mensa" AND ngc_number > 2171