Astronomy & Astrophysics General Knowledge

 


Closest to Earth:

  • Andromeda (M31) ---- 2.5 million Light Years (distance)---------- Closest Galaxy
  • Proxima Century ----- 4.423 Light year (distance)--------------- Closest Star
  • HR 6819 ------------ 1.09 Light Year (distance)--------------- Closest Black hole
  • Markarian 231 ------- 581 million Light Years (distance)---------- Closest QUASAR
  • Neowise ----------- 0.69 Astronomical Unit (distance)----------- Closest Comet
  • Geminga ----------- 800 Light Years (distance)---------------- Closest PULSAR

Distance Measuring Units:

Astronomical Unit:

An Astronomical Unit (AU) is the distance between earth and sun which is equal to 93 million miles or 153 million kilometers. Astronomical Unit is usually used to measure the distance within the solar system

Parsec:

The parsec is the unit of length used to measure the large distances to astronomical objects which are outside of the solar system. 
1 Parsec = 31 trillion kilometre                  
      1 Parsec = 210,000 astronomical units AU
1 Parsec = 3.3 Light Year                              
                     

Light Year:

Light year is an international unit of length. As defined by International Astronomical Union " A light year is the distance traveled by light in one Julian Year" 

1 Light year = 9.4 trillion kilometre          
1 Light year = 63,241 AU                               
1 Light year = 0.30 Parsec                              

Hubble Law:

The law states that the velocity of a recession of distant galaxy from our own is proportional to their distance from us.
 V = Ho R.
V = Velocity.
Ho = Hubble Constant
R = distance from one galaxy to another.

The value of Hubble constant is   70 Km /s / mega-parsec.

Comments

Post a Comment

Popular posts from this blog

AC-DC Power Supply 1 ( Block Diagram)

Image
  THEORETICAL BLOCK DIAGRAM So the basic purpose of a power supply is to convert and AC signal to DC Signal. The block diagram of the power supply would be something like given below The small electronic circuits cannot handle high voltage current. So a transformer is used to reduce the AC input and will give the required AC voltage value at output Now to convert an AC signal to DC signal A rectifier is used. The output from the rectifier is not a pure DC output. In fact, it contains a lot of ripples and it is highly not smooth. To make the DC output smooth and remove the AC content of the rectifier a filter circuit is used. This filter is either LC (inductor-capacitor) filter, RC (resistive – capacitive) filter. The choice of the filter depends on the designer of the circuit and to the type of power supply. The output now becomes a full DC with constant signal but still it is unregulated voltage. Meaning that a designer is receiving a higher than required voltage. So,
Read more

Transistor " A revolution in the technology"

Image
 Asalam O Alaikum! In the 21st century. We see the technology like never before. The world's technology before 1950s was quite limited. There was no internet, only few places could afford landline telephone and also there was no fast computers. but after 20 years in 1970s we see a lot of change in the technology.  Figure 1 Figure 2 In the above two picture there is a huge difference in the computers of 1950s and 1970s respectively. The figure1 represents the common computer of 1950s which as big as a room while the figure2 represents the computer of 1970s. With in just 20 years the computer were made not just smaller but compact as well. These 1970s computer were well efficient and fast as compared to the 1950s. Also this is not it. Within 80 years of timespan humans have made marvelous inventions and invocations in the field of electrical, electronics and computer science technologies . Nowadays computers small enough to fit in the palm of your hand as shown in figure 3. Figure 3
Read more