Stars and Constellations

Transcript

What are Stars?A star is a natural object in space that shines by itself. Important Points:- Stars shine with their own light. Stars closer to the Earth are bright and stars farther from the earth are dim. What are Constellations?Group of stars form patterns in the sky. These patterns are called Constellations. Important Points:- Today, the sky is divided into 88 Constellations. This was decided by the IAU (International Astronomical Union). Different cultures gave different names for constellationsThe constellation Orion is often represented as a hunter. There are three stars in the middle, which represent the belt of the hunter. Some people imagine that the hunter Orion, followed by his dog (constellation Canis Major), is battling a bull (constellation Taurus). Why are Constellations Useful?Constellations helped people find directions in old times Sailors and travellers used them while travelling on sea and land This was before the compass was invented The Pole Star always shows the North direction Even today, it can be used in emergency situations Other Famous ConstellationsThere are two constellations: Ursa Major and Ursa Minor In Ursa Major, there is a group of 7 stars called the Big Dipper, which looks like a big ladle (spoon). In India, It is also known as Saptaṛiṣhi. In Ursa Minor, there is a group of 7 stars called the Little Dipper, which looks like a small ladle (spoon). It also contains pole star which always points to north direction. The Pole star is known as Dhruva tārā. Indian NakshatrasIn Indian astronomy, group of stars are called nakṣhatra. Example:- Ārdrā = Betelgeuse (in Orion). Krittikā = Pleiades (in Taurus). Rohiṇī = Aldebaran (in Taurus). Activity 12.1Fig. 12.2 shows bright stars in one part of the night sky. Look at it carefully and try to imagine a pattern formed by a group of stars. Draw lines to connect the stars and make the pattern. Think of an animal or an object that is similar to the pattern drawn by you. Write its name near your pattern. Repeat the above steps and make some more patterns. Now think of an interesting story about your patterns. AnswerI saw a Potato in the sky I dreamt of making it a French fry But my mom said it looked like a tummy So, now I cry. I saw a cup in the sky But it had no coffee It was so dry. Are Star Patterns just for fun or useful too?They are both fun and useful. Long ago, star patterns helped in navigation. Sailors used them to find directions at sea. The Pole Star still helps find North today. It is still used in emergencies even now.