"Old smokers" discovered in the Milky Way: the behavior of these stars puzzled scientists. Photo
Astronomers have discovered strange stars that emit plumes of smoke. The space objects, dubbed "old smokers," challenge the notion of what happens to giant stars at the end of their lives.
It is known that when red giant stars age, they begin to pulsate. In the process, they become brighter or dimmer while shedding their outer layers. Such pulsating stars are known to science as Mira Stars (or stars like Mira Ceti). It is believed that the pulses of these stars are caused by internal plasma waves that help them eject matter into space.
These are the stars that Philip Lucas from the University of Hertfordshire in the UK and his colleagues came across while studying the center of our Milky Way galaxy using the Visible and Infrared Astronomy Telescope in Chile. However, they discovered not only Mira stars but also another unique phenomenon.
It turned out that the old red giants do not pulse but are in a steady state and then suddenly dim for six months or several years.
Further observation allowed scientists to find out that the stars emit huge plumes of dusty smoke that prevent starlight from reaching us. Months or years later, when the smoke dissipates, the light reaches observers on Earth again.
Lucas and his colleagues believe that the phenomenon they discovered may be a new way for giant stars to end their lives. Why the process is exactly like this and how it happens is a mystery to researchers.
Scientists believe that these giant stars have such a powerful gravitational field that they cannot eject any of their material into space.
Lucas notes that the fact that there is no pulsation makes it even more difficult to explain the smoke plumes. It is likely that this phenomenon may be due to the high concentration of relatively heavy elements near the galactic center, where most of these "old smokers" are located. Such a location could facilitate the formation of dust particles, which then fly away as smoke.
However, scientists are not sure if this is really the case.
Now researchers are looking for more such strange stars and have already discovered about 90 of them. It is possible that their prevalence indicates that "old smokers" may be important for the environment in the center of the Milky Way.