CONSTELLATION

• Constellations are groups of stars that appear close to each other from Earth.
• There are approximately 400 billion stars in our galaxy and about 170 million galaxies.
• The Sun is about 150 million kilometers away and it only takes 8 minutes and 20 seconds for sunlight to reach our world.
• The Sun's diameter is about 1.4 million kilometers.
• The Sun is a medium-sized star.
• Many other stars are much, much bigger.
• A star is a natural luminous body visible in the sky, especially at night.
• Stars are the most widely recognized astronomical objects and represent the most fundamental building blocks of galaxies.
• Brightness of a star depends upon its size and temperature, with a large star shining brighter than a small star and a hot star shining brighter than a cool star.
• Brightness of a star also related to the distance from the earth to the star, with star’s apparent brightness being the brightness you see from Earth.
• Hot large star that is very far from Earth does not look very bright.
• Star’s absolute brightness is the brightness the star would have if all stars were the same distance from Earth.
• Star color ranges from red to blue, with the color of the star indicating its surface temperature.
• White dwarf stars are about the size of the planet earth, while red giants and super giants are large enough to fill our solar system all the way to Jupiter.
• Stars have a life cycle that depends on the initial mass of the star, with the fate of star depending on its mass.
• All stars came from huge clouds of gas and dust called nebulae.
• The brightness of a star is observed from the Earth relies upon two variables distance and the actual brightness (absolute brightness) of the star.
• The more massive a star is the hotter its surface.
• There are 88 constellations recognized by the International Astronomy Union (IAU).
• Zodiacs are 12 constellations.
• Some constellations appear and disappear in the night sky throughout the year due to the revolution of the earth.
• Observe the stars and constellation for at least 1 - 2 hours, the constellation appears to move across night from east to west, the change in position is due to the rotation of the earth on its axis from west to east.
• Stellar Nebula- Average Star- Red Giant- Planetary Nebula- White dwarf
• Stellar Nebula - Massive Star- Red Supergiant- Supernova- Neutron Star or Black Hole
• Low to average mass of star - white dwarf
• Large mass of star - neutron star
• Very large mass of star - black hole
• Small mass or small star can lived up to billion of years and dies quietly and white dwarf is left behind
• High mass or large star can lived up to few million years that large stars dies in a supernova explosion and in their place a black hole is left behind
• Sun-Yellow-5700 celsius
• Proxima Centauri- Red- 2300
• Epsilon Iridani - Orange- 4600
• Vega- White- 9900
• Sirius- White- 10000
• Alnilam-Blue- 27000
• Red- Coolest star
• Blue- Hottest Star
• ORION AND TAURUS - 2 constellation during in the summer in the Philippines, it is not visible in the night