Star Formation

How do single stars form within huge clouds of interstellar gas and dust?

• Clouds fragment into smaller objects, forming many stars at one time.

• One star forms; other matter goes into planets, moons, asteroids, & comets.

• Clouds rotate & throw off mass until only enough is left to form one star.

What is a T Tauri star?

• a collapsing cloud of gas about to become a protostar

• a dying star

• a cool main sequence star

• a star releasing a planetary nebula

• a protostar about to become a star

Tags

NGSS.HS-ESS1-3

Objects more massive than our Sun form into stars

• much slower, over billions of years.

• in about the same time.

• much faster, over tens of thousands of years.

• not at all – they are unstable.

Stars are often born within groups known as

• clans.

• spiral waves.

• aggregates.

• clusters.

• swarms.

All stars in a stellar cluster have roughly the same

• temperature.

• color.

• distance.

• mass.

• luminosity.

Very young stars in small clusters of 10–100 members are known as

• OB associations.

• molecular cloud complexes.

• aggregates.

• globular clusters.

• hives.

Globular clusters are typically observed

• in the plane of our Galaxy.

• above or below the plane of our Galaxy.

• near to our Sun.

• in the hearts of other galaxies.

Stars in clusters & associations have about the same

• age.

• temperature.

• mass.

• color.

• luminosity.

A key feature of globular clusters is that they have

• very few cool stars.

• the oldest stars in our Galaxy.

• lots of massive main sequence stars.

• stars with very different ages.

• high concentrations of metals.

Some regions of the Milky Way’s disk appear dark because

• there are no stars there.

• stars in that direction are obscured by interstellar gas.

• stars in that direction are obscured by interstellar dust.

• numerous black holes capture all the starlight behind them.