Astronomy involves far more than just looking at stars. Comets, planets and stars, as well as collections of stars such as globular clusters (up to 1 million stars) and galaxies (up to 100 million stars) are studied. Astronomy is also concerned with how and when the universe began (the Big Bang theory being one explanation) and what will happen to it in the future. Astronomers research the nature, origin and evolution of astronomical objects to obtain a deeper understanding of the laws of physics. They are essentially physicists who use the universe as a laboratory. 

Because one cannot travel to the stars in order to retrieve pieces of them for analysis in one’s laboratory, one must use all other available information, such as radiation across the entire electromagnetic spectrum - from radio waves to gamma rays and cosmic rays - tiny particles that interact with the earth’s atmosphere or magnetic field.

Astronomers use their knowledge of mathematics and physics to study the nature, origin and evolution of astronomical objects to obtain a deeper understanding of the universe. This knowledge can be applied to developing navigational systems that will enable us to find our way through space.

Information on astronomical objects is collected by detecting their signals through space-based, ground-based, optical, gamma ray, X-ray and radio telescopes in conjunction with sensitive detecting devices. This data is analysed, often with the aid of computers, and interpreted in the framework of mathematical models incorporating the ideas of modern physics.

Astronomers do not usually work at night and sleep during the day. Many theoretical astronomers work normal hours and do not have to make any observations. Radio observations can be made during the day as well as at night, but much of the telescope’s functions are pre-programmed and do not require the constant presence of an astronomer.

Optical and infrared astronomers do the observational part of their work at night. For every week-long “observing run” at night, an astronomer will spend six to ten weeks on a normal daytime schedule, analysing data and doing other work.

Observational astronomy occupies much less of the astronomer’s time than analysing data. Observational astronomers plan research which involves the measurement of electromagnetic radiation (such as light waves). They analyse the results obtained and publish the findings so that others in the field will have access to the information.

Theoretical astronomers concentrate on developing theories concerning various aspects of the universe. It is possible to work in both theoretical and observational astronomy, although most astronomers tend to be more active in one or the other. Some astronomers also teach Mathematics or Physics at a university.

Personal Requirements

  • serious interest in Physics and Mathematics
  • above-average mathematical ability
  • able to work independently, as well as in a team
  • good interpersonal skills and adaptability
  • good imagination and an inquisitive mind
  • persistent and able to concentrate on details
  • able to take criticism and cooperate with others
  • good verbal and literal ability

How to Enter

Schooling & School Subjects

Compulsory Subjects: Mathematics, Physical Science 
Recommended subjects: Geography

What to Study

Degree: BSc degree with Physics, Mathematics, Engineering or Chemistry as major subjects, Arts majors are also acceptable. UNISA offers a BSc course in Astronomy with Physics as the second major. A compulsory two-week practical course is conducted during the second and third undergraduate year at the UNISA observatory in Pretoria.

UCT offers courses in Astronomy at second- and third-year level for students in the science faculty.
Post-graduate study: The professional astronomer has to obtain a PhD degree - e.g. UNISA

Students in the fields of Physics, Chemistry, Applied Mathematics, Mathematics or Astronomy, who obtain outstanding results at third or fourth year level (over 80 percent) may also be awarded bursaries for postgraduate studies in Astronomy by the universities themselves.

The South African Astronomical Observatory and the Radio Astronomy Observatory occasionally employ BSc graduates who may be encouraged to work for MSc or PhD degrees (as external students of a university).


  • SA Astronomical Observatory
  • Hartebeeshoek Radio Astronomy Observatory
  • universities
Job opportunities are limited, but astronomers can usually obtain research grants anywhere in the world. Although they are not always employed in astronomy itself, astronomers are seldom unemployed, because of their high level of training in Physics.

Although astronomers cannot earn their own money directly as an astronomer, there are some who become free-lance astronomy or general science writers, or even science-fiction writers.

Further Information

Astronomical Society of Southern Africa
South African Astronomical Observatory
Old Fraserburg Road
Sutherland, 6920
P O Box 25
Sutherland, 6920
Tel: (023) 571-1205

University of the Witwatersrand

Hartebeesthoek Radio Astronomy Observatory
P O Box 443
Krugersdorp, 1740
Tel: (012) 301-3100

Getting Started

  • arrange an interview with an instructor of astronomy at a university in your area
  • arrange to visit an observatory in your area
  • the South African Astronomical Observatory usually employs a few summer vacation students (typically Mathematics or Physics undergraduates) during January of each year

Programmes by Study Institutions

Related Occupations

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