12 Aurigae is a Be star in the northern constellation Auriga. It lies below the normal limit for visibility to the naked eye, having an apparent visual magnitude of 6.988.^[2] It lacks a designation from the Hipparcos catalogue. It is located just under half a degree north of Capella.^[8]

Assigned spectral classes for 12 Aurigae vary greatly from B2 to B5 and the luminosity class from V (main sequence) to Ia (luminous supergiant). Its spectrum shows prominent emission lines, but the spectrum is complicated by the appearance of sharp shell components to some of the spectral lines.^[9] The colour of the star as shown by the B-V and U-B colour indices is not consistent with an early B spectral class,^[10] leading to many estimates of its effective temperature that are much lower than expected for a B-class star.^[6][4] The expected temperature for a B5 spectral type would be 15,400 K,^[11] but most sources assign a temperature of around 8,000 K.^[6][4] Other properties also vary between different sources, for example the bolometric luminosity derived from the distance and temperature is 25 L_☉,^[6] while it is 635 L_☉ when derived by fitting the spectral energy distribution.^[5] A calculation of the stellar properties assuming the maximum possible interstellar extinction in the direction of 12 Aurigae results in a temperature of 14,336 K and a luminosity of 8,092 L_☉, although it is strongly noted that the likely extinction is much lower.^[5]