Stars with high luminosity and cool surface temperatures are called__________. – Stars with high luminosity and cool surface temperatures are called red supergiants, Mira variables, and carbon stars. These celestial giants hold a captivating allure in the cosmic tapestry, revealing insights into stellar evolution, nucleosynthesis, and the chemical enrichment of the universe.
Their distinct characteristics, pulsating behaviors, and evolutionary pathways provide a window into the intricate workings of stellar physics, inviting us to explore the mysteries that lie beyond our solar system.
Stars with High Luminosity and Cool Surface Temperatures: Stars With High Luminosity And Cool Surface Temperatures Are Called__________.
Stars with high luminosity and cool surface temperatures are known as red supergiants. These stars are classified as spectral type M and are characterized by their large size, low density, and high mass loss rates.
Red Supergiants
Red supergiants are the most luminous and coolest stars in the universe. They are typically hundreds to thousands of times larger than the Sun and have surface temperatures ranging from 3,500 to 5,000 K. Red supergiants are in the late stages of their evolution and are nearing the end of their lives.
The high luminosity of red supergiants is due to their large size and high mass. The larger the star, the more energy it can produce through nuclear fusion. The cooler surface temperatures of red supergiants are due to their low surface gravity.
The lower the surface gravity, the less the star can compress its outer layers, resulting in a cooler surface temperature.
Mira Variables
Mira variables are a type of red supergiant that exhibits periodic variations in their luminosity and surface temperature. These variations are caused by pulsations in the star’s outer layers. Mira variables are named after the star Mira, which is the prototype of this class of variable stars.
Mira variables have periods ranging from a few months to several years. During each period, the star’s luminosity and surface temperature increase and decrease. The variations in luminosity can be as large as a factor of 100 or more.
Carbon Stars
Carbon stars are a type of red supergiant that has a high abundance of carbon in its atmosphere. This carbon is produced by the star’s own nuclear fusion processes. Carbon stars are classified as spectral type C or S.
The high abundance of carbon in carbon stars affects their appearance and properties. Carbon stars are typically redder than other red supergiants and have strong molecular absorption bands in their spectra. Carbon stars are also known to be good producers of dust.
Asymptotic Giant Branch (AGB) Stars, Stars with high luminosity and cool surface temperatures are called__________.
Asymptotic giant branch (AGB) stars are a type of red supergiant that is in the late stages of its evolution. AGB stars are characterized by their high luminosity, cool surface temperatures, and high mass loss rates.
AGB stars are the progenitors of planetary nebulae. When an AGB star dies, it ejects its outer layers into space, forming a planetary nebula. The remaining core of the star becomes a white dwarf.
Clarifying Questions
What are the defining characteristics of red supergiants?
Red supergiants are massive stars with luminosities thousands of times greater than the Sun and surface temperatures below 5000 K, giving them their characteristic reddish hue.
How do Mira variables differ from other pulsating stars?
Mira variables are long-period variable stars that exhibit large variations in their brightness and surface temperature over a period of months or years.
What is the role of carbon in carbon stars?
Carbon stars are characterized by the presence of carbon in their atmospheres, which gives rise to distinctive spectral features and contributes to their unique evolutionary pathways.
