LT's (position)

it does not rise or set

at which position(s) if any, does star B rise and set?

No (the earth is blocking it)

can the observer see a star when it is located below the horizon?

Star B is always visible, star A is not visible at position 4

is either star A or B ever in an unobservable position, if so, what position?

imaginary plane

is the horizon a real, physical horizon or an imaginary plane that extends from your observing location earth out to the stars?

A3

Star A is just visible above your eastern horizon at position 1. At which numbered positions is it just visible above your western horizon

Student 2 (only star A's path carries it below the horizon for the observer)

two students are discussing weather or not star B rises and sets, Student 1: locations B1 and B3 are on my horizon because they are rising and setting like A1 and A3 Student 2: Figure 1 shows that star B is as low as it will get when it just below the horizon who do you agree with?

rising

when a star travels from a position above the observer's horizon to a position below the observers horizon, is that star rising or setting?

setting

when a star travels from a position above the observers horizon to a position below the observers horizon, is that star rising or setting?