Question

Astronomy:

6.What is a brown dwarf? Is it different from a proto-star? How?

7. What different types of gas do astronomers find in the interstellar medium?

8. Astronomers believe the Sun formed with other stars near the Orion Nebula. If that is true, why is the Sun here and not there?

9. Astronomers can tell the age of a star by the age of its cluster. How is this determined?

Answer 1

6. What is a brown dwarf?

Brown dwarf, an astronomical object that is intermediate between a planet and a star. It usually have a mass less than 0.075 that of the Sun or roughly 75 times that of Jupiter. Brown dwarfs are thought to form in the same way that stars do - from a collapsing cloud of gas and dust. Brown dwarfs are very dim and cool compared with stars.

Is it different from a proto-star?

Yes, Both star and brown dwarfs which produce energy by fusion of deuterium in their first few million years. The core of stars continue to contract and get hotter until they fuse hydrogen. Proto-stars are simply out hot enough to fuse Hydrogen and are not main sequence stars like our sun.

We know that, proto-star is the earliest stage of a star. It is before the nucleosynthesis has set in motion. A protostar is a contracting cloud of gas and dust with enough mass to form a star while a star is made up of large amount of gas and relatively small volume.

7. What different types of gas do astronomers find in the interstellar medium?

In astronomy, the interstellar medium (ISM) is the matter and radiation that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic and molecular form, as well as dust and cosmic rays.

The interstellar medium is composed primarily of hydrogen which followed by helium with trace amounts of carbon, oxygen and nitrogen.