4 - ASTROBIO - F21 - The Search for Earthlike Planets I.ppt...

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4 - AstrobiologyEXTRASOLAR PLANETS PART I
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Topics for today’s discussion…Why is it so difficult to detect planets around other stars?How do we detect planets around other stars?What can we learn about them?
Big question of mankind:Are we alone in the universe?Many speculations: Mars, Enceladus andEuropaSearch for exosolar planets was hopeless forseveral centuries because of insufficientsensitivity of instrumentation.*Exoplanet - A large body orbiting a star other than theSunExoplanets*?
Exoplanets?Speculations have existed as to whether other starscan have their own planets.Both Giordano Bruno and Nicholas of Cusaanswered this question positively a few hundredyears ago.In 1989 the first object was discovered that couldbe an extrasolar planet and that is today stillregarded as a planet candidate.In 1952, Otto Struve proposed two methods todetect exoplanets.
An Italian Dominican friar, philosopher, mathematician, poet, and cosmological theorist.He is known for his cosmological theories, which conceptually extended the then-novelCopernican model.He proposed that the stars were distant suns surrounded by their own planets, and heraised the possibility that these planets might foster life of their ownHe also insisted that the universe is infinite and could have no "center".Starting in 1593, Bruno was tried for heresy by the Roman Inquisition on charges of denialof several core Catholic doctrines.The Inquisition found him guilty, and he was burned at the stake in Rome's Campo de' Fioriin 1600. After his death, he gained considerable fame, being particularly celebrated by19th- and early 20th-century commentators who regarded him as a martyr for science,although historians have debated the extent to which his heresy trial was a response to hisastronomical views or to other aspects of his philosophy and theology.Bruno's case is still considered a landmark in the history of free thought and the emergingsciencesGiordano Bruno (1548 – 17 February 1600)
Struve, O. 1952Obs., 870, 199
40 Years Later…
Why is it hard to detect exoplanets?
Why is it hard to detect exoplanets?aa16
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40 years of Technical Innovation…Any Ideas?
40 years of Technical Innovation…Any Ideas?Mechanical stability of spectrographs –need measurement series of parts perbillion accuracy spanningyearsSoftware and computersto unravel subtleatmospheric and instrumental effectsOptical innovation (interferometry)Adaptive optics
Telescope Resolution
Anastronomicalinterferometeris an array ofseparate telescopes, mirrorsegments, or radio telescopeantennas that work togetheras a single telescope toprovide higher resolutionimages of astronomicalobjects such as stars,nebulas and galaxies bymeans ofinterferometry.
OPTICAL INTERFEROMETRY

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Term
Spring
Professor
kmn
Tags
Planet, Extrasolar planet

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