Untitled Flashcards Set

Exoplanet

A planet orbiting a star other than the Sun.

When was the first exoplanet discovered?

About 25 years ago.

Why is it hard to detect exoplanets?

Stars are often a billion times brighter than the planets.

What is a key challenge in using the transit method for exoplanet detection?

The planet's orbit must be aligned edge-on to observe the transit.

What is the Kepler spacecraft known for?

It is largely responsible for detecting exoplanets, operating since 2008.

Hot Jupiter

A Jovian planet that orbits within the frost line.

What are the main types of detection techniques for exoplanets?

Direct and indirect detection methods.

What does luminosity measure?

The total amount of power a star emits into space.

How do we know the age of the Sun?

The Sun is about 4.6 billion years old.

What causes nuclear fusion in stars?

High temperatures and pressures allow positively charged particles to overcome repulsion and fuse.

What is the proton-proton chain?

The fusion process in the Sun where 4 hydrogen atoms turn into 1 helium atom, releasing energy.

What are sunspots?

Areas on the Sun's surface that are about 2000 K cooler than the surrounding regions.

How often does the sunspot cycle occur?

Approximately every 11 years.

What are coronal mass ejections (CMEs)?

Mass ejections from the Sun's atmosphere that can affect Earth's communications and power grid.

What is the main-sequence in the Hertzprung-Russell diagram?

A region where most stars fall, reflecting a relationship between stellar temperature and mass.

What are the two main types of star clusters?

Open clusters and globular clusters.

What makes the Sun shine?

Nuclear reactions occurring in its core.

What is estimated about stellar masses?

They range from 0.08 to at least 150 times the mass of the Sun.

Why do large stars have shorter lifespans than small stars?

Large stars burn their nuclear fuel more quickly.

What is an open cluster?

A cluster containing a few thousand stars, typically located in the galactic disk.

How do scientists measure the distance to stars?

Using the parallax method for nearby stars and other methods for farther ones.

What is the solar neutrino problem?

The discrepancy in detected neutrinos caused by their ability to change type between detectors.

What is the difference between fission and fusion?

Fission splits large atoms into smaller ones; fusion combines small atoms into larger ones.

What are the layers of the Sun?

Core, radiation zone, convection zone, photosphere, chromosphere, corona, solar wind.