What is luminosity?

Use data from Table to determine, to two significant figures the radiant flux intensity measured at the Earth from  Alpha Centauri.

This question is about Sirius and Arcturus. With the help of calculations and data from Table, show that Sirius is brighter than Arcturus.

Write the quadrants in which the following points lie:

$\left(-4,7\right)$

A group of astronomers have determined the radiant flux intensity F from a star and its distance d. The percentage uncertainty in F is $1.2\%$ and the percentage uncertainty in d is $2.5\%$. What is the percentage uncertainty in the calculated value of the luminosity of the star?

Use data from Table to determine to two significant figures the luminosity (in W) of Canopus.

Use data from table to determine two significant figures the radiant flux intensity measured at the Earth from Sirius.

Use data from Table to determine, to two significant figures the luminosity (in W) of Vega.

Neptune is the farthest known planet from the Sun in the Solar System. Its distance from the Sun is 30 times greater than the distance of the Earth from the Sun. The radiant flux intensity from the Sun at the Earth is $1400 \mathrm{W} {\mathrm{m}}^{-2}$.

A space probe is close to Neptune.

Calculate the maximum radiant power received by an instrument of cross-sectional area $1.0 {\mathrm{cm}}^2$ on this space probe.