Author Question: The hottest star in the Orion Nebula is about the same mass as the Sun. Indicate whether the ... (Read 97 times)

jasdeep_brar · **on:** Jul 27, 2018

The hottest star in the Orion Nebula is about the same mass as the Sun.

Indicate whether the statement is true or false

Question 2

In the context of binary stars, briefly explain visual binary system, spectroscopic binary system, and eclipsing binary system.

What will be an ideal response?

pami445 · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

False

Answer to Question 2

In a visual binary system, the two stars are separately visible in the telescope and astronomers can watch the stars orbit each other over periods of years or decades. From that, astronomers can find the orbital period and, if the distance of the system from Earth can be found, the size of the orbits. That is enough to find the masses of the stars.If the stars in a binary system are close together, a telescopic view, limited by diffraction and atmospheric seeing, shows a single point of light. Only by looking at a spectrum, which is formed by light from both stars and contains spectral lines from both, can astronomers tell that there are two stars present and not one. Such a system is a spectroscopic binary system.Although spectroscopic binaries are very common, they are not as useful as visual binaries. Astronomers can find the orbital period easily, but they can't find the true size of the orbits because there is no way to find the angle at which the orbits are tipped. That means they can't find the true masses of a spectroscopic binary. All they can find is a lower limit to the masses. If the plane of the orbits is nearly edge-on to Earth, then the stars can cross in front of each other as seen from Earth. When one star moves in front of the other, it blocks some of the light, and the star is eclipsed. Such a system is called an eclipsing binary system.