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r*=13.6 km MPA1 EOS
r*=13.6 km MPA1 EOS

... scattered light contribution, which accounts for flux scattered off an equatorial accretion disk to the observer including time delays in the scattered light. We give limits to mass and radius for XTE J1807-294 and compare these to limits determined for SAX J1808-3658 and XTE J1814-334 previously de ...
Answers to Odd-Numbered Exercises and Problems
Answers to Odd-Numbered Exercises and Problems

... || Suppose that on earth you can jump straight up a distance of 50 cm. Can you escape from a 4.0-km-diameter asteroid with a mass of 1.0 * 1014 kg? ||| A projectile is fired straight away from the moon from a base on the far side of the moon, away from the earth. What is the projectile’s escape spee ...
Astronomy 328 Midterm Exam - Department of Physics and Astronomy
Astronomy 328 Midterm Exam - Department of Physics and Astronomy

... Exam rules: You may consult your sheet of formulas during the exam. This sheet can contain any formulas or values for constants that you think you need but it cannot contain worked out problems or concepts. You must turn in your formula sheet with the exam. Calculators are permitted. Good luck. ...
DTU_9e_ch12
DTU_9e_ch12

... emission nebulae are excited by UV radiation from young, massive stars. Dust grains obscure part of NGC 2024, giving the appearance of black streaks, while the distinctively shaped dust cloud, called the Horsehead Nebula, blocks the light from the background nebula IC 434. The Horsehead Nebula is pa ...
overview - FOSSweb
overview - FOSSweb

... sequences of changes and to look for patterns in these changes. As they observe changes, such as the movement of an object’s shadow during the course of a day, and the positions of the sun and the moon, they will find patterns in these movements. They can draw the Moon’s shape for each evening on a ...
Lithium abundances along the red giant branch: FLAMES
Lithium abundances along the red giant branch: FLAMES

Notes (PowerPoint)
Notes (PowerPoint)

... Built great observatories on his island Fights, duels, possibly died from being drunk, but also careful astronomical measurements • Convinced astronomy needed good measurements ...
07optics_8inch_orion
07optics_8inch_orion

... 1.Magnitude Scale: Hipparchus of Rhodes (160-127 B.C) assigns “magnitudes” to stars to represent brightness. The eye can see down to 6th magnitude ...


... 3. THE RR LYRAE STARS IN M15 In Clement’s (2002) data base of variables stars, a total of 158 variable stars are known, from which approximately 104 are RR Lyrae type stars. In this work, 33 known RR Lyrae stars, identified in Figs. 1 and 2 and listed in Table 4, have been studied. For all the stars ...
Giant “Pulsar” Studies with the Compact Array Abstract
Giant “Pulsar” Studies with the Compact Array Abstract

... Studying stars as a population of radio sources is hard. To begin with, the menagerie of stellar radio emitters is large and vociferous: objects from cool dwarfs to giants to pre-main sequence T Tauri stars to the hotter Ap and Bp stars, to Wolf-Rayet stars all exhibit fascinating radio properties ( ...
Sample pages 2 PDF
Sample pages 2 PDF

PHYS3380_102815_bw - The University of Texas at Dallas
PHYS3380_102815_bw - The University of Texas at Dallas

... (surface)~10-4 kg m-3. Much smaller than mean density (mean)~1.4103 kg m-3 (which we derived). We know the surface temperature (Teff=5780K) is much smaller than its minimum mean temperature (2106 K). Thus we make two approximations for the surface boundary conditions: = T = 0 at r=rs i.e. that ...
E3 – Stellar distances
E3 – Stellar distances

... • At distances greater than Mpc, neither parallax nor spectroscopic parallax can be relied upon to measure the distance to a star. • When we observe another galaxy, all of the stars in that galaxy are approximately the same distance away from the earth. What we really need is a light source of known ...
Brown Dwarfs and M Dwarfs
Brown Dwarfs and M Dwarfs

... • Flares on BDs may have different properties from M dwarfs because the surrounding gas is low density (e.g., strong nonthermal radio emission with little thermal X-ray emission). ...
Published by the Association Pro ISSI No. 37, May 2016
Published by the Association Pro ISSI No. 37, May 2016

... nature. Stars are born during the collapse of giant nebulae that are large interstellar clouds of dust, hydrogen, helium and other ionized gases, (Fig. 2) . These clouds are really huge, they may measure several light years across. They are not stable in the long run; rather, internal turbulences ca ...
Variable Stars – II. Pulsating stars
Variable Stars – II. Pulsating stars

thefixedstarsinnatal.. - Saptarishis Astrology
thefixedstarsinnatal.. - Saptarishis Astrology

... with the exception of the square and opposition, the aspects to the body of a star with latitude do not fall in the zodiacal degrees one would expect, as may be seen by the example given in the Appendix under Formula 8. It is a simple matter, however, to calculate the correct places in which such as ...
printer-friendly version of benchmark
printer-friendly version of benchmark

... For most of a star’s existence, nuclear fusion is converting hydrogen (really protons) into helium (really helium nuclei) in the star’s core. This phase is called the main sequence, derived from a star’s properties when graphed on the Hertzsprung-Russell, or H-R, Diagram (named after two astronomers ...
From the reviews - Astrofoto Portugal
From the reviews - Astrofoto Portugal

... constellations in their basic form (northern hemisphere only, the southern hemisphere is covered later in the book). The second chapter deals with the basic nature of and the brightness of stars. The text here, as in rest of the book, is non technical which makes for a more relaxed form of learning ...
A Spectroscopic Study of the RV Tauri Stars TT Oph... Guillermo Hernandez , Donald K. Walter , Jennifer Cash
A Spectroscopic Study of the RV Tauri Stars TT Oph... Guillermo Hernandez , Donald K. Walter , Jennifer Cash

... lines as well as the Ca II H and K lines and others in absorption. Below: One of our spectra of UZ Oph with the Ca II H and K lines and others in absorption. ...
Measuring the Milky Way
Measuring the Milky Way

... the center of the Galaxy, which is the source of these phenomena. An accretion disk surrounding the black hole emits enormous amounts of radiation. ...
Spectral Classification of Stars
Spectral Classification of Stars

April 2006 Newsletter PDF - Cowichan Valley Starfinders Society
April 2006 Newsletter PDF - Cowichan Valley Starfinders Society

Nebula Beginnings - University of Dayton
Nebula Beginnings - University of Dayton

... titanic supernova explosions scatter this material back into space where it is used to create new generations of stars. This is the mechanism by which the gas and dust that formed our solar system became enriched with the elements that sustain life on this planet. Hubble spectroscopic observations w ...
Stellar Evolution – Life of a Star
Stellar Evolution – Life of a Star

... • Stars often begin as a nebulae. A nebulae is a cloud of gas and dust in space. Some nebulaes are regions where new stars are being formed, while others are the remains of dead or dying stars. The word nebulae comes from the Latin word for cloud. • In the nebulae, gravity pulls the materials togeth ...
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Hipparcos



Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial objects on the sky. This permitted the accurate determination of proper motions and parallaxes of stars, allowing a determination of their distance and tangential velocity. When combined with radial-velocity measurements from spectroscopy, this pinpointed all six quantities needed to determine the motion of stars. The resulting Hipparcos Catalogue, a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision Tycho Catalogue of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. Hipparcos‍ '​ follow-up mission, Gaia, was launched in 2013.The word ""Hipparcos"" is an acronym for High precision parallax collecting satellite and also a reference to the ancient Greek astronomer Hipparchus of Nicaea, who is noted for applications of trigonometry to astronomy and his discovery of the precession of the equinoxes.
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