What astronomical phenomenon allows astronomers to observe Red Giants in distant galaxies across cosmological distances?
Answer
Their thousands of solar luminosities make them individually resolvable even when distant.
The massive increase in total light output (luminosity) from Red Giants allows them to stand out and be detected across vast cosmic separations, whereas the far more numerous Main Sequence stars are too dim.
Frequently Asked Questions
What maintains the stable equilibrium of a star, like our Sun, while it is on the Main Sequence?What is the immediate trigger for the dramatic expansion of a Sun-like star into a Red Giant?According to the Stefan-Boltzmann Law, what causes the Red Giant phase to be vastly more luminous than the Main Sequence star?What causes the surface color of an evolved star to shift toward the red end of the spectrum?For a star similar in mass to the Sun, approximately how much can its total luminosity increase upon becoming a Red Giant?What is the primary difference in the mechanism driving energy output between a Main Sequence star and a Red Giant?Which class of stars evolves into the even grander objects known as Red Supergiants?What physical concept distinguishes between 'flux' and 'luminosity' in stellar physics?What governs the visual color of a star, linking it directly to its surface temperature?What astronomical phenomenon allows astronomers to observe Red Giants in distant galaxies across cosmological distances?What is the approximate radius change a Sun-like star experiences when expanding into a Red Giant?