HD 137509, also known as NN Apodis, is a class B9p star in the constellation Apus. Its apparent magnitude is 6.87 and it is approximately 640 light years away based on parallax. It shines with a luminosity approximately 111 times that of the Sun and has a surface temperature of 12804 K. It has one of the strongest magnetic fields recorded for a chemically peculiar star.
References
HD 137509 Wikipedia(Text) CC BY-SA