... In temperate latitudes, this is a good time to see halos formed by clouds of ice crystals high in the atmosphere where the temperature is always well down below -30 deg. ... The most prominent halos, however, appear quite close to the sun where it can be uncomfortably bright to look. ... In a sense, halos are like rainbows, glories and coronae in that they require the presence of a bright source of light, the Sun or the Moon, and water floating in the air. ...

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... Because of the Earth 's gravity, atmosphere is horizontally stratified (see, e.g., Kelley, 1989). Its structure can be organized by using the neutral gas temperature, as shown in the figure from mid-latitudes (note the logarithmic altitude scale). When going upward from the ground within the lowermost atmospheric region, troposphere, the temperature decreases up to about 10 km altitude (tropopause). ... Here the radiation also ionizes the neutral atmosphere, creating the ionosphere . ... 1989. ...

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• Space Weather
• Solar wind and IMF [Oulu]
• Ionosphere [Oulu]

... The related observations clearly evidence both global motions and turbulence in the upper Jovian atmosphere. Keywords: solar system, giant planets, atmospheres, Jupiter . To explain both an upper atmospheric thermal excess observed in the Jupiter atmosphere by the Voyager missions and a permanent enhancement of the H Ly- brightness observed near the equator (Clarke et al. ... These Doppler shifts appear as being the signature of global H motions in the upper atmosphere of Jupiter. ...

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• Introduction to HST Data Handbook v8.0
• Introduction
• STIS Data Handbook

... The Armagh Observatory (see http://star.arm.ac.uk/ ) is the oldest continuously functioning astronomical research institute in the UK and Ireland, having been in existence for more than 210 years. ... The Astropark, which is managed by the Observatory, includes two sundials, a number of outdoor exhibits and interpretation panels (see http://star.arm.ac.uk/astropark/ ), and scale models of the solar system and the larger Universe, constructed to linear and exponential scales respectively. ... Staff ....

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• Principal Areas of Research
• R CORONAE BOREALIS STARS
• Meteors in Planetary Atmospheres

Next: Photometric Corrections Up: Long-Slit and 1D Previous: Long-Slit and 1D . This chapter describes the long-slit љ reduction package in a general way. ... The package provides about 50 basic commands to perform the calibration and to display the results, defined in the context LONG . ... The context SPEC is a low-level context including general utility commands required by the different spectroscopy packages ECHELLE , IRSPEC and LONG . ... This interface is described in the Appendix . ...

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• HyperLEDA: documentation
• References

Next: CCD Operation Up: Charge Coupled Devices (CCDs) Previous: Charge Coupled Devices (CCDs) . ... However it is only now that a number of important X-ray astronomical applications of CCDs have reached critical development stages, so that this is an appropriate time to review the application of space-borne CCD instruments to cosmic X-ray astronomy, and highlight the particular concerns which are being addressed for X-ray instruments, as distinct from optical applications. ...

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• Home Page

Getting To Know Layers . ... Layers in an image can be any size. ... You have the ability to toggle the visibility of a layer, so that it does not contribute to the final image. ... The layers dialog, with the Ops menu expanded . The primary tool for working with layers in GIMP is the Layers dialog. This gives you an overview of all the layers in an image, and provides the toggled areas for linking and visibility. ... You can also toggle a layer's Preserve Transparency option. ... Step 1 | ...

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• Ranking
• Introduction to The Web Nebulae
• APOD: 2009 January 6 - Jupiter Eclipsing Ganymede

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

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• The ATNF Visualisation Suite

Next: The course and unit level Up: Ceilidh - On Line C Tutoring System Previous: Introduction . ... To enter the system at the general level, the appropriate command (which should have been set up by your computer systems administrator) is . ... q quit this session fs find student | ... text ceilidh only) in X the courses available appear on main window.This command tells you which courses are available and supported by the Ceilidh system, their full title and their abbreviation. vp . ...

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• Introduction
• From Power Up To Bash Prompt: Introduction

... Sagittarius Dwarf Irregular Galaxy . ... How old is this galaxy? The nearby Local Group galaxy dubbed the Sagittarius Dwarf Irregular Galaxy (SagDIG) is not only very small but also has relatively few elements more massive than helium. ... Moon Over Shiraz . ... Early morning risers around the world have enjoyed the sight of bright planets in this week's predawn skies - further enhanced by the celestial spectacle of the waning crescent Moon. ... Leo A: Nearby Dwarf Irregular Galaxy . ...

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... The eleven years cycle of Sun's activity is approaching its maximum! From August 24th to 29th a team of astronomers, engineers and astro-photographers will travel to southern Greenland to observe the Northern Lights (Aurora Borealis), a phenomenon expected to be particularly spectacular during this period. ... Auroras . The wonderful celestial spectacle of the aurora occurs when very energetic particles from the Sun reach the Earth's atmosphere via the solar wind. ... About GLORIA . ...

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• Total solar eclipse broadcast from Kenya with GLORIA
• GLORIA expedition to Peru to broadcast live the Total Lunar Eclips

... Листок 1 (32K) | ... The conjecture, (RH), made by Riemann in 1859, that all nontrivial zeros of ?(s) lie on the line Re(s)=1/2, is still open. I will give an introduction to the theory of the Riemann zeta function, with an emphasis on facts relevant to (RH), in particular equivalent formulations. Generalizations to Dedekind's zeta function and the Selberg class will be considered. ... The functional equation . Hardy's theorem (?(s) has an infinity of zeros on the line Re(s)=1/2) . ...

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• Braid groups (Spring 2003)
• An introduction to elliptic operators
• Jets (introduction) (Fall 1999)

Next: Observational Zoo of Binaries Up: No Title Previous: Contents . In the early 1980s, our understanding of binary star evolution љ based on the pioneer work by Paczynski (1971)[ 150 ], Tutukov and Yungelson (1973)[ 195 ], van den Heuvel and Heise (1972)[ 201 ], allowed us to construct a general evolutionary scenario љ which successfully explained the genesis of well-studied normal stars and offered potential explanation for new X-ray sources discovered in space experiments. ...

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• Simple Universe
• Modern Irish Banknotes (1928 to date)

... Contamination on optical surfaces degrades the throughput of an optical system. ... Contamination is particularly pernicious on the unprotected aluminum that is commonly used on the large first-surface mirrors of reflecting telescopes. ... During that period, the covers of their protective cases is opened whenever the 3.5-m telescope primary mirror cover is opened for nighttime observing. ... CO2 clean exposed mirrors in SS case. ... Light scattering measurements performed on cleaned mirrors. ...

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• Performance of the SDSS cloud scanner I: the first movie
• Rotation range
• TUI:TUI Menu:Log Windows

. Next: To display a particular Up: *display, xdisplay, xexamine* - Previous: To view a section . tv> display ``xdata$rp110590.qp[block=4][1673:1800,2273:2400]'' . This is a tricky operation. The order of the instructions is critical. The image must first be compressed, then the section specified using the coordinates of the compressed image (logical coordinates). The above will display a 128 128 section. rsdc@cfa.harvard.edu . 1998-06-10

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• To display a particular energy band
• To display a particular time interval
• IRAF/PROS

Next: Historical Notes Up: The Chirplet Transform: Previous: The Chirplet Transform: . ... One of these TF methods, the short-time Fourier transform (STFT), has been used extensively for analyzing speech, music, and other non-stationary signals. ... Another time-frequency representation (which might more appropriately be called a time-scale representation) is the well-known wavelet transformheil-walnut,mallat:theory,daubechies:transform,strangwavelets. ... Historical Notes . ...

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• Historical Notes
• Analysis of a cosine wave
• Introduction

This menu contains items that illustrate and explain some of the basic concepts that are represented by any operating system and by UNIX in particular. It helps you to understand why UNIX behaves in the way that it does. ... what an operating system is . the structure of the UNIX operating system . about commands and processes . the UNIX file system . ... Understanding these concepts you will help you make better use of UNIX and have a clearer idea about what it is you are doing. ...

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• Horizontal Rules
• Introduction to HTML 3.0

The Wideband Arecibo Pulsar Processor Home Page . Important Note: WAPP has been under constant development and upgrade over last 2 years. ... The resulting correlation functions are written to disk as 16 bit unsigned integers with minimal processing. The initial system will have two IF channels of up to 100 MHz each. ... Thus, WAPP has two bandwidth modes: 100 MHz and 50 MHz. ... 16 Bit WAPP Modes . ... 100 MHz . ... 3 bits . ... 3.75 . 256 . ... BW50,IF1,Q3 . 50 MHz . ... TBD . ...

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• NVIDIA Accelerated Linux Graphics Driver README and Installation Guide
• General Introduction and Consortium Guidelines
• Sixto Gonz†бlez National Astronomy and Ionosphere Center (Arecibo Observatory)

... Astronomy index . Mechanics index . Sun index . ... The sections of "Stargazers" covering the Sun was an afterthought. The rest of the material was mostly complete when a teacher of astronomy, adapting the material for his course, pointed out an omission. ... Yes, indeed--and therefore this part was added. ... However, almost all the material on the Sun fits seamlessly into the sections that precede it or follow it, and lesson plans have been provided for sections #S-1 to #S-7 as well. ...

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• A Brief History of Magnetospheric Physics Before the Spaceflight Era
• Explaining the Sundial
• Brief History Introduction

ATMoB "Double Star Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston ­ in particular, double, triple, and multiple stars. Introduction: Double, triple, and multiple stars are the "Rodney Dangerfields" of the night sky. ... W hile they can be observed under a variety of sky conditions, double stars ­ especially close ones ­ are best viewed on nights when the seeing is steady. ... The direction from a star to Polaris is north. ...

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• An Inexpensive Dobsonian Slow Motion Control