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: http://www.stsci.edu/~inr/thisweek1/2012/thisweek156.html
Дата изменения: Tue Jul 3 00:23:44 2012 Дата индексирования: Tue Feb 5 03:28:26 2013 Кодировка: Поисковые слова: earth's atmosphere |
Program Number | Principal Investigator | Program Title |
---|---|---|
12210 | Adam S. Bolton, University of Utah | SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller Radii |
12461 | Adam Riess, The Johns Hopkins University | Supernova Follow-up for MCT |
12473 | David Kent Sing, University of Exeter | An Optical Transmission Spectral Survey of hot-Jupiter Exoplanetary Atmospheres |
12474 | Boris T. Gaensicke, The University of Warwick | The frequency and chemical composition of rocky planetary debris around young white dwarfs |
12488 | Mattia Negrello, Open University | SNAPshot observations of gravitational lens systems discovered via wide-field Herschel imaging |
12493 | Ian McGreer, University of Arizona | A Candidate Lensed Quasar at z=6.25 |
12500 | Sugata Kaviraj, Imperial College of Science Technology and Medicine | High-resolution UV studies of SAURON galaxies with WFC3: constraining recent star formation and its drivers in local early-type galaxies |
12517 | Francesco R. Ferraro, Universita di Bologna | COSMIC-LAB: Hunting for optical companions to binary MSPs in Globular Clusters |
12519 | Raghvendra Sahai, Jet Propulsion Laboratory | Newly Discovered LMC Preplanetary Nebulae as Probes of Stellar Evolution |
12521 | Xin Liu, University of California - Los Angeles | The Frequency and Demographics of Dual Active Galactic Nuclei |
12533 | Crystal Martin, University of California - Santa Barbara | Escape of Lyman-Alpha Photons from Dusty Starbursts |
12534 | Harry Teplitz, California Institute of Technology | The Panchromatic Hubble Ultra Deep Field: Ultraviolet Coverage |
12536 | Varsha Kulkarni, University of South Carolina Research Foundation | Sub-damped Lyman-alpha Absorbers at z < 0.6: An Unexplored Terrain in the Quest for Cosmic Metals |
12537 | David Ehrenreich, Universite de Grenoble I | Venus observed as an extrasolar planet |
12546 | R. Brent Tully, University of Hawaii | The Geometry and Kinematics of the Local Volume |
12568 | Matthew A. Malkan, University of California - Los Angeles | WFC3 Infrared Spectroscopic Parallel Survey WISP: A Survey of Star Formation Across Cosmic Time |
12572 | Michele Trenti, University of Cambridge | The Brightest of Reionizing Galaxies Pure Parallel Survey |
12575 | Anthony H. Gonzalez, University of Florida | New Constraints on Intragroup Light and the Baryon Budget in Galaxy Groups |
12582 | Ariel Goobar, Stockholm University | Probing the explosion environment and origin of Type Ia supernovae |
12585 | Sara Michelle Petty, University of California - Los Angeles | Unveiling the Physical Structures of the Most Luminous IR Galaxies Discovered by WISE at z>1.6 |
12586 | Kailash C. Sahu, Space Telescope Science Institute | Detecting and Measuring the Masses of Isolated Black Holes and Neutron Stars through Astrometric Microlensing |
12591 | Elena Gallo, University of Michigan | A Chandra/HST census of accreting black holes and nuclear star clusters in the local universe |
12605 | Giampaolo Piotto, Universita di Padova | Advances in Understanding Multiple Stellar Generations in Globular Clusters |
12659 | Joaquin Vieira, California Institute of Technology | Strongly Lensed Dusty Star Forming Galaxies: Probing the Physics of Massive Galaxy Formation |
12801 | Harold A. Weaver, The Johns Hopkins University Applied Physics Laboratory | Hubble Deep Search for Debris and Satellites in the Pluto System in Support of NASA's New Horizons Mission |
GO 12474: The frequency and chemical composition of rocky planetary debris around young white dwarfs
GO 12493: A Candidate Lensed Quasar at z=6.25
GO 12533: Escape of lyman-Alpha Photons from Dusty Starbursts
GO 12537: Venus observed as an extrasolar planet
![]() An image of the 2004 Venus transit - with a terrestrial interloper (taken by Jerry Zhu |
Extrasolar planets that transit their parent star from the vantage point of the Earth are much sought after in exoplanet research. Not only do those systems eliminate the sin(i) uncertainty in estimating planetary masses,they also provide an opportunity to probe atmospheric properties through comparative spectroscopy of the host star during and outside primary transit - differencing the spectra can reveal absorption features introduced as the starlight passes through the exoplanet atmosphere. Earth's inhabitants are also occasionally in a position to view Solar System transits, as bodies interior to the earth's orbit, notably Mercury and Venus, pass across the face of the Sun. The planetary transits occur when inferior conjunction (the planet lies directly between Earth and the Sun) occurs close to the orbital node (where the planetary orbit crosses the ecliptic. In the case of Mercury, this happens relatively frequently, with transits in May or November and occuring at intervals of 7, 13 or 33 years - the most recent events were November 15 1999, May 7 2003 and November 8 2006. Venusian transits occur in June or December, but at a much lower frequency. Transits occur in pairs, 8 years apart, separated by gaps of 121.5 and 105.5 years, with the cycle recurring every 243 years. Thus, the June transits of 1761 and 1769 were followed by December transits in 1874 and 1882, and repeated as June transits in 2004 and 2012. The 18th and 19th century transits were the targets of numerous scientific expeditions, including James Cook's expedition to Tahiti in 1769, since accurate timing could be applied to measuring the astronomical unit, and scaling the solar system. Nowadays, there are much more effective ways of measuring that parameter (that don't have to deal with the uncertainties introduced by the 'black drop"). However, the upcoming transit can be turned to advantage in probing our sensitivity to detecting the atmospheres of terrestrial exoplanets. Direct observations of the Sun are out of the question with HST - indeed, Hubble can only observe Venus itself when the planet is at its furthest elongation from the Sun (see HST's observations in support of Venus express - GO 12433 ). However, HST can observe reflected sunlight by observing the Moon. The present program uses the Space Telescope Imaging Spectrograph to observe two regions of the lunar surface, near the craters Hipparchus and Dollond, during the Venusian transit on June 5, 2012. Those observations will be differenced against reference lunar spectra, with an initial set being taken this week. |