SN 1998aq is a nearby supernova located in the intermediate spiral galaxy NGC 3982, offset 18″ west and 7″ of the galactic nucleus.

[4] The event was not visible on a prior check by Armstrong made April 7.

[5] It reached peak brightness on April 27, and 15 days later had declined by 1.14 magnitudes in the B (blue) band.

[4] An absorption feature of singly-ionized carbon was (probably) detected nine days before maximum, an indication of unburned ash left over from the original carbon-oxygen core of the progenitor white dwarf.

[7] Brightness calibration using Cepheid variables in NGC 3982 gives a peak absolute magnitude estimate of at least −19.47±0.15 (assuming no extinction in the host galaxy).