globular clusters?

Question

In globular clusters, the brightest stars will be

A.Massive blue main sequence stars.
B.Red super giants.
C.T Tauri stars.
D.Blue stragglers.
E.Planetary nebulae.

Answer 1

I googled "star brightness" and found several sites, many of which were pretty technical. The site below [1] had this to say:

"Stars come in a variety of types. For ordinary stars (i.e. the so- called main sequence stars, which include our Sun and about 90% of the known stars), a star's color tells us its brightness...
All stars, late in their life, change from main-sequence average-sized stars to swollen red giants. Most stars change again from swollen red giants to pulsating variable stars before they finally die. These pulsating variable stars, called Cepheids after the first one discovered, are very large, bright yellow stars."

At another site [2], I found this about T Tauri stars:
"A very young, lightweight star, less than 10 million years old and under 3 solar masses, that it still undergoing gravitational contraction; it represents an intermediate stage between a protostar and a low-mass main sequence star like the Sun.
T Tauri stars are found only in nebulae or very young clusters..."

I found this about "blue stragglers" [3] :
""Blue Stragglers" are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. Globular clusters are located in galactic halos..."

And this about "planetary nebulae" [4] :
"The evolution of stars of mass up to 8 - 12 times the mass of the Sun ends with the formation of a planetary nebula and the production of a white dwarf...Planetary nebulae are characterized by a shell of material (of mass roughly 10 to 20 % of a solar mass) moving away from a hot (temperatures of 20,000 to more than 100,000 Kelvins), faint star (in their center) at a speed of 10 to 30 kilometers per second."

However, as far as "globular clusters go [5] :
"Globular clusters typically contain a number of variable stars, in particular RR Lyrae stars which were once called "Cluster Variables" because of their abundance in globulars."
And Wikipedia says [6] :
"The most massive main sequence stars in a globular cluster will also have the highest absolute magnitude, and these will be the first to evolve into the giant star stage."

So, I'd say that answer A (main sequence) is probably correct, at least for clusters that have them. BUT, answer D (Blue Stragglers) also looks pretty good. You should probably do a little more research. Check the sites below and follow some of the links. Happy hunting!

Answer 2

frist 2 humorous. nicely first each Galaxy has a black hollow contained in the middle. so if 2 were to collide the black holes might want to lack of a extra effective be conscious, devour one yet another and change into higher

Answer 3

the answer is B, red super giants.

Answer 4

A.