Astronomer

An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. Historians often argue that ancient astronomers were priests and that this duality led to the rise of astrology. It is important to recognize that basically all astronomers before about 1750 were astrologers as well, there having been no distinction between the two.

Unlike most scientists, astronomers cannot directly interact with the celestial bodies, and so instead must resort to detailed observation in order to make discoveries. Generally, astronomers use telescopes or other imaging equipment to make such observations.

Famous Astronomers

Astronomer	Contribution
Hipparchus and Ptolemy	Determined the positions of about 1,000 bright stars, tried to explain the puzzles of astronomy without refuting the commonly believed geocentric model of universe and classified stars by magnitude.
Aristarchus	First known person to propound the heliocentric model of universe
Nicolaus Copernicus	Reitererated the heliocentric model of universe.
Galileo Galilei	Was the first to use the telescope to observe the sky.
Johannes Kepler	Suggested the elliptical orbits.
Isaac Newton	Used laws of gravitation and motion to predict exact orbits of planets.
Edwin Hubble	Discovered the expansion of the universe. (Hubble's Law).

See also

• List of astronomers
• Amateur astronomy

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There is also a well-known painting by Johannes Vermeer titled The Astronomer, which is often linked to Vermeer's The Geographer. These paintings are both thought to represent the growing influence and rise in prominence of scientific enquiry in Europe at the time of their painting, 1668-69.

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