Astronomer
From Wikipedia, the free encyclopedia
An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics.
Contents |
[edit] A sampling of 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 geocentric model of universe and classified stars by magnitude. |
| Aristarchus of Samos | First known person to propound the heliocentric model of universe. Attempted to calculate the sizes and distances of the Sun and Moon. |
| Nasir al-Din al-Tusi | This Persian astronomer gave the first extant exposition of the whole system of plane and spherical trigonometry. Made very accurate tables of planetary movements and named many stars. Developed the Tusi-couple which resolves linear motion into the sum of two circular motions. He also calculated the value of 51' for the precession of the equinoxes and contributed to construction and usage of astrolabe. |
| Nicolaus Copernicus | First exponent of heliocentrism in modern times. |
| Tycho Brahe | Did develop many important astronomical instruments, and achieved accurate measurments of the heavens by improving scentific methodology and by designing instruments on a large scale. His measurements of the orbit of Mars were very important to the development of astronomy. |
| Johannes Kepler | Suggested the elliptical orbits of planets, and propounded his Laws of Planetary Motion. |
| Galileo Galilei | Was the first to use the telescope to observe the sky. Condemned to house arrest for his discoveries by Inquisitional edict, which was lifted 359 years later by Pope John Paul II. |
| Isaac Newton | Published Philosophiae Naturalis Principia Mathematica (1687), containing the "Newton's laws of motion", which are fundamental to mechanical physics, and which explained Kepler's laws of planetary motion. Predicted the orbits of the planets. |
| Subrahmanyan Chandrasekhar | Extensive work on the internal mechanisms of stars, particularly known for determining the effect of special relativity on stars, including being the first to calculate the Chandrasekhar limit, which he did, without a calculator, on a boat journey. |
| Henrietta Swan Leavitt | Catalogued Cepheid variable stars in the Magellanic Clouds, in 1912 discovered the relationship between luminosty and periodicity in Cepheids -- leading to Hertzsprung's later work. |
| Ejnar Hertzsprung | Determined the distance to several Cepheids, when Cepheids were detected in other galaxies such as the Andromeda galaxy, the distance to those galaxies could then be determined. |
| Edwin Hubble | Discovered the expansion of the universe. (Hubble's Law) The Hubble Orbiting Space Telescope was named in his honor. |
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 inquiry in Europe at the time of their painting, 1668-69.
[edit] The modern astronomer
The progress in technology and wealth has enabled many more types of Astronomers than ever before. Advances in imaging technology have brought about an unprecedented sharing of visual and sub-visual phenomena in the sky, both day and night events. Web proliferation of space derived data has enabled many phenomena to be observed by more astronomers than ever before, especially auroral displays, comet appearances, and occultations. Advances in software to guide telescopes and cameras, and measure the light values accurately, had enabled higher quality images and vast contributions to be made by many more astronomers, than previously. Yet another type of Astronomer can be identified; the website builder and promoter, sharing science and sky images as part of the growth in networking astronomy, in-turn, encouraging the growth by disseminating both result and technique. Even the recent discovery of earth impact craters by so-called 'arm-chair' astronomers, using Google Earth, is a newly enabled valid type of Astronomer. Astronomers are often mathematicians, but more than likely looking through a telescope or camera and recording the image. Observing, measuring, and sharing occultation events is a growing activity, highly important to adding knowledge of and future predictions of sky objects, such as the shape of the moon, asteroids, and planets to a very high accuracy, with a modest investment in equipment.
The division between professional and amateur astronomer is more blurred than ever before, with amateur astronomers contributing to many fields of knowledge, often significant, micro-lensing as a planet discovery method for instance. The division is often a perceived gap, inside astronomy there is often no gap.
[edit] Current activities by astronomers
- measuring orbital data of objects
- measuring chemical composition of objects
- measuring light values of sky objects
- imaging solar activity
- imaging auroral activity
- imaging comets
- teaching astronomy
- building astronomy websites
- promoting astronomy
- running email lists to share and disseminate info quickly.
- traveling to astronomical events, such as eclipse, special telescopes, conferences, etc.
- developing optics
- manufacturing electronic equipment
- observing astronomical events, recording and sharing the information.
- observing and recording stars and other celestial bodies
- observing the phazes of a star
- viewing other galaxies
