Astronomy: Its Related Fields And Scope

 Astronomy is the study of the universe, everything which is beyond the Earth's atmosphere. It may include objects which can be seen by the naked eye, like the Sun, the moon, few planets like Mars, Jupiter, Saturn, constellations like the Big Dipper, Orion, etc. and a few stars; objects which can be observed by some instruments like optical telescopes, ultraviolet or infrared telescopes, X-Ray telescopes, microwave or radio telescopes; and objects which cannot be seen either with the help of powerful telescopes and only their presence could be predicted, like the unobservable universe.

The oldest natural science is also a multidisciplinary field that uses the concept of mathematics, physics, chemistry, geography, and biology to understand the emergence and evolution of the universe (or who knows, the multiverse!). It is mainly divided into two parts, observational astronomy, and theoretical astronomy. 

Observational Astronomy is the branch of astronomy that is concerned with observing, recording, and analyzing data collected using electromagnetic radiations. It is mainly divided into Optical Astronomy, Ultra-Violet Astronomy, Infra-Red Astronomy, X-Ray Astronomy, Radio Astronomy, Gamma-Ray Astronomy, and analyzing Microwaves using specially designed telescopes. 

Optical or Visible Light Astronomy is the oldest branch of observational astronomy. Earlier, people used to see with their naked eyes and predict; further came the telescopes. Modern-day optical astronomy uses telescopes and detectors to record.

Ultra-Violet Astronomy uses ultraviolet rays that emerge from objects and analyze them using the equipment. It is best suited for the study of thermal emission and spectral emission lines from hot blue stars (short-lived, hot, and massive stars). Planetary nebulae, supernova remnants, and active galactic nuclei can also be observed using Ultra-Violet telescopes. The famous Hubble Space telescope is a UV-Visible telescope.

Infra-Red Astronomy is based on the detection and analysis of the Infra-Red portion of the electromagnetic spectrum. It is useful for studying objects that are so cold to radiate any visible light such as planets, circumstellar discs, or studying the objects whose visible light is blocked by space dust. Infra-Red Observational Astronomy is quite useful as it gives a lot of information about the chemistry of the universe. Also, it is useful in detecting water in comets.

X-Ray Astronomy uses X-Ray radiations produced by synchrotron emissions (emissions resulting from electrons orbiting magnetic field lines), thermal emissions from very thin and thick gases. Because X-Rays are absorbed in the atmosphere of the Earth, detection, and recording of X-Ray signals happen at high altitudes. X-ray binaries, pulsars, supernova remnants, elliptical galaxies, clusters of galaxies, and active galactic nuclei can be observed and studied using X-Ray telescopes.

Radio Astronomy differs from any other Observational Astronomy division as it treats the signal as waves rather than discrete photons, unlike UV and IR Astronomy. Objects in the universe could be weak emitters of visible light, hence radio astronomy is used to resolve the issue. Radio Astronomy uses radio waves which are either produced by synchrotron emissions or thermal emissions. Several spectral lines produced by interstellar gases, like hydrogen are observable at radio wavelengths. It has detected many new objects in the observable universe, in the past including pulsars and rapidly spinning neutron stars. 

Gamma-ray Astronomy observes astronomical objects which are highly energetic. Neutron stars, pulsars, and black holes emit gamma rays via gamma-ray bursts. Gamma-rays are not yet directly detected successfully by any telescope. The Crompton Gamma Ray Observatory detects the flashes of visible light that are produced when gamma rays are absorbed by the Earth's atmosphere.

The other branch of astronomy is Theoretical Astronomy. It uses the data from observational astronomy and the basic fundamentals of physics and chemistry to give reasons for astronomical phenomena and objects. Theories like general and specific Relativity, stellar dynamics and evolution, galaxy formation, the Big Bang Theory, cosmic inflation, dark matter, dark energy, etc. are notable works in the field. 

Astrophysics is the branch of astronomy that applies the fundamentals of physics like mechanics, electromagnetism, statistical physics, thermodynamics, quantum mechanics, relativity, etc. in understanding astronomical objects and physics. It primarily focuses on the nature of the objects and phenomena rather than studying the relative motion of objects to each other. The different electromagnetic emissions-by the Sun, the planets, other stars, galaxies, interstellar medium, and cosmic microwave background-are used to study their physical properties like luminosity, density, temperature, and chemical composition. 

Astrochemistry is the study of reactions of molecules in the universe as they interact with different radiations. It also includes the study of the abundance of elements present in the universe and focuses on any new element discovery. This helps in understanding the formation, atomic and chemical composition, evolution, and the fate of molecular gas clouds.

Astrobiology is the interdisciplinary science field including molecular biology, biophysics, biochemistry, exoplanetology, cosmology, and astronomy. It is concerned with the origin, evolution, and future of life in the universe. Nowadays, the main focus of scientists is to find if there is any intelligent life in the universe.

Planetary Science is the study of celestial objects that orbit the stars, either planets or their satellites; primarily focusing on our own solar system. It also includes the study of asteroids, comets, meteors, and meteorites. 

Astronomy, as you have read till now is a varied field and it has many career aspects. One can go and make a career in observational astronomy or if the person is more imaginative than logical, he or she may become a theoretical astronomer. One can become a Cosmologist if one wants to study the universe as a whole and not as different elements. Being an Astronaut is the most loved career aspect in the field. 

Rest is left for the next article, till then STAY CONNECTED.