Stars + Astronomy

• Stars - It is a massive, luminous sphere of plasma held together by its own gravity.
• Nebula - Stars are born from swirling clouds of hydrogen gas in deep space between stars.
• Proto star - A radiating ball and accumulation of cloud of gas formed due to the condensation of mutual gravitational attraction which further lead to the birth of a star.
• Average Star - Enough light on heat energy to maintain the star.
• Main Sequence Star - Normal, Mature stars, that are using their nuclear fuel at a steady rate.
• Red Giants - Stars that are big and bright but low temperature.
• White Dwarfs - These are small, faint, white-hot stars.
• Black Dwarfs - Stars that are dark in color that can never been seen because the helium gases that gives light to the star are totally loss.
• Supernova - Is a powerful and luminous stellar explosion.
• Black Hole - Is a region of space time where gravity is so strong that nothing no particles or even electromagnetic such as light can escape from it.
• Milky Way - Is a barred spiral galaxy with a floating rotating disc.
• Brightness - measure the amount of light reaching Earth by luminosity and distance
• Luminosity - The total energy emitted by a star (depends on size + temperature and distance)
• Stars are classified by their size/mass, temperature, color, and brightness
• The brightness decreases as the inverse square of the distance ( 2 light year - 1/4 (1/2^2 )
• Stars have a life cycle that depends on their initial mass
• constellation - a group of stars when seen from Earth form a pattern
• gravitational force - force of attraction beween two objects due to the mass of the objects
• law of universal gravitational: strength of force depends on object's mass and the distance between them
• orbit: regular, repeating path that an object in space follows another object
• inertia: the forward motion of an object in space that rests or continues moving in a straight line at a constant speed
• astronomical unit: the average distance between the earth and the sun.
• parallax: the apparent shift in the position of a star as a result of the Earth's motion around the Sun (when viewed from two different spots)
• baseline: a minimum or starting point used for comparisons. (distance between two points)