Below is a chart showing the apparent magnitudes
of the 10 brightest stars (other than the sun) as seen from Earth.
Visual interpretation and linear regression analysis of the lightcurve to determine the rate of decay following maximum brightness identifies a number of distinct changes in the rates of decline in the apparent magnitude
of the SN.
The absolute magnitude is defined as the apparent magnitude
measured at 10 parsecs from the source.
And that's why astronomers measures a star's brightness two ways: by its apparent magnitude
(how bright a star looks when seen from Earth) and by its absolute magnitude (how bright a star would look if it were 33 light-years away from Earth).
These include: time of appearance (UT); apparent magnitude
(brightness); type (shower member, or random, 'background' sporadic); constellation in which seen; presence and duration of any persistent train.