12 Lacertae

OB association (Lac OB1).^[14][15][16]

luminosity class of a giant star. It has been known to be variable for more than a century and has been extensively studied.^[17] The variable radial velocity of the star was discovered by W. S. Adams in 1912, and the light variations were established by 1919. The pulsational nature of the variability was shown by P. Ledoux in 1951, which led to one of the first world-wide observing campaigns with the star as its target. Dutch mathematician F. J. M. Barning analyzed the resulting data in 1963 and found four separate cycles of variation. By 1994, six periods had been confirmed.^[5]

hybrid pulsator, showing mixed behaviors of a Beta Cephei variable and a slowly pulsating B-type star.^[19]

luminosity of the Sun from its photosphere at an effective temperature of 23,809 K.^[9] The estimated rotational velocity of the primary at the equator is 52±5 km/s;^[21] about 10% of its break-up velocity.^[19] However, seismic models suggest the core region is rotating much more rapidly with a rotational velocity of up to 100 km/s, and thus the star is undergoing differential rotation.^[21]

nebulosity at a separation of 0.6 light-years from the pair that is most likely a bow shock.^[22]