Stars and Constellations

• The closest star to our solar system is Proxima Centauri.
• The word "constellation" comes from the Latin word "constellatio," which means "set of stars." These patterns of stars were given names to help people navigate the night sky.
• Stars are huge celestial bodies made of gases such as helium and hydrogen.
• Stars produce heat and light due to a process called nuclear fusion.
• Star sizes depend on their mass, the more mass they have, the bigger and brighter they will be.
• Stars are measured in what we call “Stellar Classification” which is split into 2 parts-- the spectral and luminosity classes.
• Stars begin to form in a nebula.
• Gravity will pull the dust and gas in the nebula together and friction will cause them to heat up and lead to the development of a protostar.
• As the protostar become hotter, the hydrogen atoms will start to fuse and turn into helium. This is called nuclear fusion.
• Stars go through a process called stellar evolution.
•  Small to medium-sized stars use their nuclear fuel and their cores shrink and heat up. The outer layers expand and the star becomes a red giant and eventually, a white dwarf. The outer layers of the star spread in space and form a nebula.
• Small to medium-sized stars use their nuclear fuel and their cores shrink and heat up. The outer layers expand and the star becomes a red giant and eventually, a white dwarf. The outer layers of the star spread in space and form a nebula.
• Massive stars die after they consume all their nuclear fuel and they explode due to gravity. This explosion is called a supernova.
• Neutron stars are formed when a star collapses and the extreme pressure and density cause the protons and electrons to form neutrons.
• Neutron stars are what’s left behind after a supernova explosion.
• Stars at least 3 times the mass of our sun collapse onto themselves and form a bottomless well of gravity called a black hole.
• Black holes begin to form when the hydrogen atoms fuse into helium, creating energy in the form of radiation. 
• This radiation of blac holes pushes against gravity and maintains a balance with it. But the fusion doesn’t stop there. The heavier elements fuse until they reach iron. This process doesn’t generate energy.
• Constellation is a group of star patterns in the sky.
• Circumpolar constellations are seen all year long. They are located north of the celestial pole.
• Zodiacal constellations move along the ecliptic or zodiac. There are 12 of them.
• Seasonal constellations change throughout the year depending on the season.
• Circumpolar constellations include Ursa Major, Cassiopeia, and Draco.
• Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces are the 12 zodiacal constellations.
• Cygnus, Orion, and Crux are seasonal constellations.
• Polaris is called the north star as it points to the true north.