Download Astronomical Figures

Astronomical Figures
190 BC - 120 BC
Mathematicians
Hipparchus, Astronomer
*Devised latitudes and longitudes and created the apparent magnitude scale by dividing
stars into categories according to their brightness (1-6).
(It wasn’t until the 1850's that scientists saw the brightest objects in the sky as brighter
than first magnitude, so the system now has a rating of zero and negative magnitudes.) In
fact, Sirius, the brightest star has a magnitude of -1.46, as seen from Earth. *If the
magnitude is higher (fainter) than 6, the naked eye can’t see it.
90 - 168
Mathematicians
Ptolemy, Astronomer / Geographer
*Wrote the first astronomical account now known as the Almagest
("Mathematical Treatise")
*Ptolemy used Hipparchus's system of epicycles and eccentric circles to
explain his geocentric theory of the universe. He believed the planets and
sun orbit around the earth. This system became known as the Ptolemaic
system.
1473 - 1543
Christians
Copernicus, Earth moves around the Sun
*Formulated the heliocentric theory that the universe orbits around the sun.
1546 - 1601
Mathematicians
Tycho Brahe
*Designed and built instruments, he also calibrated them and checked
their accuracy periodically.
1564 - 1642
Mathematicians
Galileo Galilei, Father of Modern Science
*Made improvements to the telescope and astronomical observations, such as
the imperfect surface of the Moon, the Phases of Venus, the Moons of Jupiter,
and sunspots of the Sun.
1571 - 1630
Mathematicians
Johannes Kepler, Laws Planetary Motion
*Three laws of planetary motion that bear his name published in 1609 and
1619).
1625 - 1712
Scientists
Giovanni Cassini, Astronomer
*Determined the obliquity of the ecliptic at 23 deg 29' and studied the effects.
1643 - 1727
Alchemists
Isaac Newton, Theory of Gravitation
*Worked on optics and gravitation
1656 - 1742
Mathematicians
Edmond Halley, Astronomer
*mapped out stars and is known because of Haley’s Comet.
1701 - 1744
Inventors
Anders Celsius, Temperature Scale
*In 1742, he divided the temperature scale of a mercury thermometer at 760mm mercury
air pressure into 100 degrees, where 100 is the freezing point and 0 the boiling point of
water.
1738 - 1822
Composers
Herschel, Discovered Uranus - 1781
*discovered Uranus and infrared radiation.
1811 - 1877
Mathematicians
Le Verrier, Co-discovery of Neptune
*studied the causes of disturbances in the Solar System. His work led to improved
knowledge of the masses of the planets, the scale of the Solar System, and the
velocity.
1819 - 1892
Discoveries
John Adams, Discovered Neptune - 1845
* predicted the existence of Neptune.
1889 - 1953
Mathematicians
Edwin Hubble, Big Bang Theory
* devised a classification system for the various galaxies he observed, sorting them by
content, distance, shape, and brightness; it was then he noticed redshifts in the
emission of light from the galaxies.
1894 - 1966
Christians
Lemaître, Proposed Big Bang Theory
*proposed what became known as the Big Bang theory.
1905 - 1973
Scientists
Gerard Kuiper, Astronomer
*considered the father of modern planetary science for his wide ranging studies of the
solar system. *established the atmosphere of Saturn's moon, Titan, and discovered
Saturn's moon, Miranda, and Neptune's Nereid. Kuiper's prediction of comets traveling
near the orbit of Neptune, the Kuiper belt.