The Amazing Universe

In our previous article, we have discussed the three major cosmic distance scales which are Astronomical Unit (AU), Light Year (LY), and Parsec (Pc), and their significance in astronomy. You came to know how these units ease up our process of studying and understanding this Amazing Universe. In this article, we will solely discuss one of these units which is Parsec. By the end of this article, you will be able to understand its derivation, definition, significance, and how the small difference between light year and parsec creates a huge difference in the world of astronomy.  An artist’s impression of 14 galaxies that are in the process of merging.(NRAO/AUI/NSF; S. Dagnello) So before we proceed, let's have a brief overview of all these units. Astronomical Unit  i.e. AU, is the distance from the center of the Sun to a point at which a particle of almost negligible mass revolves in a stationary orbit with an orbital period of 365.2568983 days (One Gauss...

We all are familiar with some of the most common units of length that are meter(m) and kilometer(km). But every branch of science has its own order of work field, and so the units of measurement which are convenient to the scientists or researchers or any person who is studying that branch. For example, the material scientist is more convenient with Micron (10^-6 m), atomic physicist deals easily with Angstrom (10^-10 m), a nuclear physicist deals with Fermi (10^-15 m), and so on. Although there is an SI unit of length i.e. meter, it would be so absurd to state the size of an atom in meters and kilometers. The space beyond the Earth is so incredibly large that the units of measurement that are convenient for us in everyday life can become gigantic. The distances between planets, and especially between stars, can become so big in miles and kilometers that they become difficult to manage. When we talk about the enormity of the universe, it's easy to come up with big numbers - but i...

Astrophysics is defined as the branch of astronomy that employs the principles of physics and chemistry to ascertain the nature of astronomical objects, rather than their positions or motions in space. It applies chemical and physical laws to explain the birth, life, and death of celestial objects like stars, planets, galaxies, nebulae, black holes, quasars, and many others in the universe.   (Image: Hubble Telescope) History of Astrophysics It all began with Sir Isaac Newton. While astronomy is one of the oldest sciences, the theoretical concept of astrophysics was given by Newton. Prior to Newton, many astronomers described the motion of heavenly bodies using complex mathematical models but without any physical basis. Newton proved that celestial objects and earth and its objects are subject to the same physical laws. He did this by showing that the motion of the moon and planets, and the trajectory of a cannonball around the Earth can be easily explained simultaneously by ...