we all look Up in sky what we see ??? easy to say Moon and Stars for those who just look up but if you ask this to astro lover person he will say I can see Constellations, planets, Clusters, galaxy. this article will help you to take Basic Observation of sky.We are going to know about Constellations. its patterns and Position in night sky So lets start Our Journey.
If you lost somewhere in night how you will find direction?
Here we have our Five friends (Constellations ) which will help you to find one direction which is North. This 5 constellations are as follows :
1.Ursa Major (Great bear or Big Dipper )
These Constellations will help you to find Polaris or North Direction. Now here Some people think that the POLARIS Star must be Very bright but it is not like that Polaris is a Normal Star which has 1.97 magnitude Brightness.
How to spot Polaris ?
So to Find him You need to follow these steps:
1. Find Ursa Major ( Big Dipper) its big Seven star pattern Constellation. (See the picture below.)
2- very good you able to see the Big dipper now there are two stars who's names are Dubhe (Kratu ) & Merak (Pulah) you need to draw a line towards the North star and there you will find your friend Polaris.
This method is shown below:
This is the easy way to find North. now you need to find other three Directions right ? So for that you have to face towards North star. you know in front you have a North then its Opposite will be SOUTH direction and on right hand side you have your EAST & left hand side will be your west. Easy ?? yeah this is the easy way to get directions but if there is No Big dipper in night sky then what you will do ? here is the answer you need to find letter "M" in sky.. not kidding there is one constellation which looks like letter "M" it is called as CASSIOPEIA. yeah it looks like letter "M". see the image bellow it is "M"
hmmmmm now you got it.... Now its time to find North star.. take two star from left or right its all up to you... now you need to draw perpendicular and go straight you will find Your polaris. Method is shown bellow:
Light travels through a vacuum at its maximum speed of about ( 3.0 × 10 8m/s), and in a straight path.Light travels at slower speeds through different materials, such as glass or air. (A material through which light travels is called a medium , plural: media.) When traveling from one medium to another, some light will be reflected at the surface of the new medium.The light that continues through the new medium will either speed up or slow down depending on how fast it can travel through each medium. For example, light travels more quickly through air than through water. The refractive index of a medium is the ratio of the speed of light in a vacuum to the speed of light in the medium. The higher the refractive index, the more light is slowed down by the substance.
Index of Refraction for Some Common Substances Substance Index of Refraction
Vacuum - 1
Air - 1.0003
Water - 1.3
Ethyl alcohol - 1.4
Diamond - 2.4
When light hits a surface that it can't travel through, it bounces back. If the surface is smooth, like
a mirror, the light will reflect in a predictable way. If the surface is flat, the angle at which a beam of light approaches the mirror will be equal to the angle at which the beam is reflected, so i = r in the diagram below.