Who are Astronomers?

Who are these people who call themselves astronomers?

Since time immemorial the heavens have fascinated and intrigued. Evidence of lunar cycle recordings have been found from 25,000 years ago, the Chinese first recorded the observation of a supernova in 185AD and again in 1054AD, and in the 900's  the first known descriptions of the Andromeda Galaxy were recorded by a Persian astronomer. Since these times, observations of the celestial sky have evolved from eye-sight observations to space-based telescopes and radio-interferometry observatories such as the Very Long Baseline Array.

Astronomers are those who study the nature of the universe and phemonena which occur throughout it. They include professional researchers at universities and other research institutions, and amateur astronomers who observe heavenly bodies as a hobby. Astronomical investigations involve both theoretical and observational research, ranging from modeling the approximate behaviour of stellar nuclei, to observations of celestial bodies, radiation and the interstellar medium. Such investigations utilise a range of tools including computer simulators, data reduction software and telescopes designed for observing specific wavelengths of the electromagnetic spectrum.

Astronomers are not only involved in research of celestial objects but are also involved in teaching, and collaborative work to design and create new instrumentation, to improve resolution and sensitivity or to investigate physical principles. 

For instance, Einstein’s theory of general relativity predicts the existence of gravitational waves produced by the acceleration of massive bodies. Despite numerous experiments conducted towards such an outcome, gravitational waves are one of few effects predicted by this theorem remaining to be experimentally verified. By observing the frequencies of millisecond pulsars (rapidly rotating neutron stars which emit radiation beams) over a period of time, and inspecting for slight changes in these frequencies, some astronomers are hopeful of discovering these waves. By using a range of pulsars throughout the galaxy, the probability of detecting gravitational waves, if they exist, increases. In essence, this experimental method utilizes pulsars as Galactic-scale detectors! (Click image to view an article on pulsars and laser-based interferometers for gravitational-wave detection)

Pulsars produce signals with such precise signals that some rival atomic clocks for time-keeping accuracy. These signals can even be recorded and the magnitude over time plotted to produce a sound plot of their frequency:

So what else could we learn from these universal time-keepers? This is just one specialised topic within the field of astronomy. Imagine a galaxy filled with celestial objects and phenomena to be studied, understood and, like pulsars, even used as tools themselves. Now try to imagine 100 billion galaxies like this... Mind-boggling isn't it?