Advanced Binary Star Systems Quiz

What is the primary definition of a Roche lobe in a binary star system?

• The physical surface of a star in the system.

• The orbital path of a star around the other.

• The region around a star where its gravity dominates over the other star’s gravity.

• The area where the two stars' atmospheres are equal.

The shape of a Roche lobe is often described as:

• A perfect sphere.

• A cube.

• Approximately teardrop-shaped, with the apex pointing towards the companion star.

• A spiral.

The apex of the teardrop shape of the Roche lobe points towards which location?

• The center of mass of the system.

• The farthest point in the orbit of the star.

• The L1 Lagrangian point of the system, which is towards the other star.

• The point where the stars' orbits cross each other.

What is the L1 Lagrangian point in the context of Roche lobes?

• The point where the stars' orbits are most distant.

• The center of mass of the binary system.

• A point of gravitational equilibrium between the two stars, often associated with mass transfer.

• The point where centrifugal force is greatest.

How does the Roche lobe differ from the Roche sphere?

• They are the same thing.

• The Roche lobe is smaller than the Roche sphere.

• The Roche lobe is the region of gravitational dominance in a binary system, while the Roche sphere is the gravitational sphere of influence of one body.

• The Roche sphere is an older concept.

What happens when a star exceeds its Roche lobe?

• It becomes more stable.

• Its gravitational pull increases.

• It shrinks dramatically in size.

• Material from the star can transfer to its companion through the L1 point.

The phenomenon of mass transfer due to a star exceeding its Roche lobe is referred to as:

• Stellar wind transfer.

• Roche Lobe Overflow (RLOF).

• Tidal stripping.

• Gravitational radiation.

According to the sources, what is the main factor determining the size of a Roche lobe?

• The temperature of the star.

• The luminosity of the star.

• The mass ratio of the two stars and the orbital separation.

• The age of the star.

What does Eggleton's formula approximate?

• The total mass of a binary system.

• The eccentricity of the orbit.

• The Roche radius of a star in a binary system.

• The angular momentum of the system.

According to the sources, what are the consequences of mass transfer in a binary system due to Roche lobe overflow?

• The system becomes more stable.

• The orbit always expands.

• It can lead to various astronomical phenomena, such as X-ray binaries and supernovae.

• The two stars will always merge.