Hello,

Yes, AG Car is a most interesting star and one that we should continue to monitor for changes in brightness and to study its changes in behaviour so we can gain a better understanding.

As we look in the direction of the constellation Carina in the southern Milky Way we are looking in line of sight along the Carina Arm of our Milky Way galaxy and therefore see a rich concentration of star clusters, bright and dark nebulae and interesting variable stars. Because of the distance involved to AG Car, it is reasonable to assume there is a considerable amount of interstellar material, both gas and dust, and this would absorb some of the blue light from the more distant objects (interstellar reddening) but would not cause the light variations seen occurring in AG Car.

The most likely cause of the small amplitude variations is irregular or semi periodic at best oscillations within the stars outer layers – massive stars such as AG Car in inherently unstable and pulsation is one way they can shed some of their excess mass as they try to gain stability.

Recent theoretical models of the SDOR stars like AG Car suggest that stars of such high mass must be, or have been in the past, multiple star systems, but it appears there is no observational evidence (yet) to suggest AG Car does have a companion. All the more reason to keep studying these stars as there is so much more yet to learn.