Topic > Exoplanets - 1261

Humans have longed to believe in exoplanets, for surely there must be planets elsewhere in the universe. Claims of supposedly discovered exoplanets can be traced back to 1855 when Captain S.W. Jacobs of the Madras Observatory claimed to have discovered a planet orbiting a binary system (Jacobs 1855), to 1991 when a team of astronomers announced they then retracted the alleged discovery of an exoplanet around a pulsar star (Lyne and Bailes 1992). Planets are extremely difficult to detect because they are a very weak light source and the light from the parent star is much brighter and essentially blocks the light from a planet (Winters 1996). It was not until 1992 that the first exoplanets orbiting a pulsar star were confirmed (Wolszczan and Frail 1992). Finally, in 1995, the first exoplanet orbiting a main sequence star, a star like our Sun, was discovered (Mayor and Queloz 1995). The very first exoplanets were found to be two Earth-like planets orbiting a pulsar star (Wolszczan and Frail 1992). A pulsar star is a neutron star that constantly emits beams of radiation, these radiation beams occur due to a misalignment of the neutron star's rotation axis and its magnetic axis (Pulsars 2011). The misalignment coupled with a neutron star's intense magnetic field and rapid rotation causes it to create intense electric fields in which electrons are accelerated to high speeds where they produce radiation in the form of light. Although pulsar stars always emit radiation, they appear to pulsate in relation to distant observers because the neutron star's rotation causes radiation within its magnetic field to "pulse" in and out of an observer's line. ... middle of paper ...... Astronomical Society, 228-231. Blackwell Scientific Publications, for the Royal Astronomical Society. http://books.google.com/books?id=pQsAAAAAMAAJ.8. Lyne, A.G. and M. Bailes. 1992. “No planets orbiting PSR1829-10.” Nature 355 (January 16): 213.9. Mayor, Michel and Didier Queloz. 1995. “A Jupiter-Mass Companion to a Solar-Type Star.” Nature 378 (November 23): 355-359. doi:10.1038/378355a0.10. Winters, Jeffrey. 1996. The planet at 51 Peg. discovermagazine.com. January 1st. http://discovermagazine.com/1996/jan/theplanetat51peg620.11. Wolszczan, A. 1994. “Confirmation of Earth-mass planets orbiting the millisecond pulsar PSR B1257+12.” Science 264 (April 22): 538-542. doi:10.1126/science.264.5158.538.12. Wolszczan, A., and D. A. Frail. 1992. “A planetary system around the millisecond pulsar PSR1257+12.” Nature 355 (January 9): 145-147. doi:10.1038/355145a0.