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The Denver Observer December 2017
The Denver DECEMBER 2017 OBSERVER Messier 76, the Little Dumbbell Nebula, one of the deep-sky objects featured in this month’s “Skies.” Image © Joe Gafford. DECEMBER SKIES by Zachary Singer The Solar System of view in your ’scope will include the Moon’s Sky Calendar 3 Full Moon December will be a decent month for eastern section and the star, with plenty of 10 Last-Quarter Moon planetary events; though some planets are room. 17 New Moon slipping from view, others will take their I recommend you observe early—it 26 First-Quarter Moon place. We also have an occultation of Alde- should be a beautiful view, with the star a baran; as seen from Denver, the Moon will bright spark near the Moon’s edge, and over pass in front of the star at approximately the following minutes (they’ll go fast, just like In the Observer 4:06 PM, on the 30th. At that point, with the recent solar eclipse did), you can see the Moon move in its orbit around us, using the sunset still more than half an hour away, the President’s Message . .2 star won’t be visible to the naked eye, but it star for a benchmark. (Before 4:00 PM, look Society Directory. 2 should be in a telescope if you know where for Aldebaran outside the square, but along to look: Imagine a square drawn just large the diagonal from the Moon’s center to that Schedule of Events . 2 enough to touch the edges of the Moon, and lower-left edge.) About Denver Astronomical Society . -
Binocular Universe: You're My Hero! December 2010
Binocular Universe: You're My Hero! December 2010 Phil Harrington on't you just love a happy ending? I know I do. Picture this. Princess Andromeda, a helpless damsel in distress, chained to a rock as a ferocious D sea monster loomed nearby. Just when all appeared lost, our hero -- Perseus! -- plunges out of the sky, kills the monster, and sweeps up our maiden in his arms. Together, they fly off into the sunset on his winged horse to live happily ever after. Such is the stuff of myths and legends. That story, the legend of Perseus and Andromeda, was recounted in last month's column when we visited some binocular targets within the constellation Cassiopeia. In mythology, Queen Cassiopeia was Andromeda's mother, and the cause for her peril in the first place. Left: Autumn star map from Star Watch by Phil Harrington Above: Finder chart for this month's Binocular Universe. Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm This month, we return to the scene of the rescue, to our hero, Perseus. He stands in our sky to the east of Cassiopeia and Andromeda, should the Queen's bragging get her daughter into hot water again. The constellation's brightest star, Mirfak (Alpha [α] Persei), lies about two-thirds of the way along a line that stretches from Pegasus to the bright star Capella in Auriga. Shining at magnitude +1.8, Mirfak is classified as a class F5 white supergiant. It radiates some 5,000 times the energy of our Sun and has a diameter 62 times larger. -
Abstracts Connecting to the Boston University Network
20th Cambridge Workshop: Cool Stars, Stellar Systems, and the Sun July 29 - Aug 3, 2018 Boston / Cambridge, USA Abstracts Connecting to the Boston University Network 1. Select network ”BU Guest (unencrypted)” 2. Once connected, open a web browser and try to navigate to a website. You should be redirected to https://safeconnect.bu.edu:9443 for registration. If the page does not automatically redirect, go to bu.edu to be brought to the login page. 3. Enter the login information: Guest Username: CoolStars20 Password: CoolStars20 Click to accept the conditions then log in. ii Foreword Our story starts on January 31, 1980 when a small group of about 50 astronomers came to- gether, organized by Andrea Dupree, to discuss the results from the new high-energy satel- lites IUE and Einstein. Called “Cool Stars, Stellar Systems, and the Sun,” the meeting empha- sized the solar stellar connection and focused discussion on “several topics … in which the similarity is manifest: the structures of chromospheres and coronae, stellar activity, and the phenomena of mass loss,” according to the preface of the resulting, “Special Report of the Smithsonian Astrophysical Observatory.” We could easily have chosen the same topics for this meeting. Over the summer of 1980, the group met again in Bonas, France and then back in Cambridge in 1981. Nearly 40 years on, I am comfortable saying these workshops have evolved to be the premier conference series for cool star research. Cool Stars has been held largely biennially, alternating between North America and Europe. Over that time, the field of stellar astro- physics has been upended several times, first by results from Hubble, then ROSAT, then Keck and other large aperture ground-based adaptive optics telescopes. -
Appendix A: Scientific Notation
Appendix A: Scientific Notation Since in astronomy we often have to deal with large numbers, writing a lot of zeros is not only cumbersome, but also inefficient and difficult to count. Scientists use the system of scientific notation, where the number of zeros is short handed to a superscript. For example, 10 has one zero and is written as 101 in scientific notation. Similarly, 100 is 102, 100 is 103. So we have: 103 equals a thousand, 106 equals a million, 109 is called a billion (U.S. usage), and 1012 a trillion. Now the U.S. federal government budget is in the trillions of dollars, ordinary people really cannot grasp the magnitude of the number. In the metric system, the prefix kilo- stands for 1,000, e.g., a kilogram. For a million, the prefix mega- is used, e.g. megaton (1,000,000 or 106 ton). A billion hertz (a unit of frequency) is gigahertz, although I have not heard of the use of a giga-meter. More rarely still is the use of tera (1012). For small numbers, the practice is similar. 0.1 is 10À1, 0.01 is 10À2, and 0.001 is 10À3. The prefix of milli- refers to 10À3, e.g. as in millimeter, whereas a micro- second is 10À6 ¼ 0.000001 s. It is now trendy to talk about nano-technology, which refers to solid-state device with sizes on the scale of 10À9 m, or about 10 times the size of an atom. With this kind of shorthand convenience, one can really go overboard. -
Astrometry and Optics During the Past 2000 Years
1 Astrometry and optics during the past 2000 years Erik Høg Niels Bohr Institute, Copenhagen, Denmark 2011.05.03: Collection of reports from November 2008 ABSTRACT: The satellite missions Hipparcos and Gaia by the European Space Agency will together bring a decrease of astrometric errors by a factor 10000, four orders of magnitude, more than was achieved during the preceding 500 years. This modern development of astrometry was at first obtained by photoelectric astrometry. An experiment with this technique in 1925 led to the Hipparcos satellite mission in the years 1989-93 as described in the following reports Nos. 1 and 10. The report No. 11 is about the subsequent period of space astrometry with CCDs in a scanning satellite. This period began in 1992 with my proposal of a mission called Roemer, which led to the Gaia mission due for launch in 2013. My contributions to the history of astrometry and optics are based on 50 years of work in the field of astrometry but the reports cover spans of time within the past 2000 years, e.g., 400 years of astrometry, 650 years of optics, and the “miraculous” approval of the Hipparcos satellite mission during a few months of 1980. 2011.05.03: Collection of reports from November 2008. The following contains overview with summary and link to the reports Nos. 1-9 from 2008 and Nos. 10-13 from 2011. The reports are collected in two big file, see details on p.8. CONTENTS of Nos. 1-9 from 2008 No. Title Overview with links to all reports 2 1 Bengt Strömgren and modern astrometry: 5 Development of photoelectric astrometry including the Hipparcos mission 1A Bengt Strömgren and modern astrometry .. -
The Transfiguration in the Theology of Gregory Palamas And
Duquesne University Duquesne Scholarship Collection Electronic Theses and Dissertations Spring 2015 Deus in se et Deus pro nobis: The rT ansfiguration in the Theology of Gregory Palamas and Its Importance for Catholic Theology Cory Hayes Follow this and additional works at: https://dsc.duq.edu/etd Recommended Citation Hayes, C. (2015). Deus in se et Deus pro nobis: The rT ansfiguration in the Theology of Gregory Palamas and Its Importance for Catholic Theology (Doctoral dissertation, Duquesne University). Retrieved from https://dsc.duq.edu/etd/640 This Immediate Access is brought to you for free and open access by Duquesne Scholarship Collection. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Duquesne Scholarship Collection. For more information, please contact [email protected]. DEUS IN SE ET DEUS PRO NOBIS: THE TRANSFIGURATION IN THE THEOLOGY OF GREGORY PALAMAS AND ITS IMPORTANCE FOR CATHOLIC THEOLOGY A Dissertation Submitted to the McAnulty Graduate School of Liberal Arts Duquesne University In partial fulfillment of the requirements for the degree of Doctor of Philosophy By Cory J. Hayes May 2015 Copyright by Cory J. Hayes 2015 DEUS IN SE ET DEUS PRO NOBIS: THE TRANSFIGURATION IN THE THEOLOGY OF GREGORY PALAMAS AND ITS IMPORTANCE FOR CATHOLIC THEOLOGY By Cory J. Hayes Approved March 31, 2015 _______________________________ ______________________________ Dr. Bogdan Bucur Dr. Radu Bordeianu Associate Professor of Theology Associate Professor of Theology (Committee Chair) (Committee Member) _______________________________ Dr. Christiaan Kappes Professor of Liturgy and Patristics Saints Cyril and Methodius Byzantine Catholic Seminary (Committee Member) ________________________________ ______________________________ Dr. James Swindal Dr. -
Dynamical Dust Traps in Misaligned Circumbinary Discs: Analytical Theory and Numerical Simulations
MNRAS 000,1–10 (2021) Preprint 24 March 2021 Compiled using MNRAS LATEX style file v3.0 Dynamical dust traps in misaligned circumbinary discs: analytical theory and numerical simulations Cristiano Longarini,1¢ Giuseppe Lodato,1 Claudia Toci1 and Hossam Aly2 1Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano, Italy 2Univ Lyon, Univ Claude Bernard Lyon 1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, F-69230, Saint-Genis-Laval, France Accepted XXX. Received YYY; in original form ZZZ ABSTRACT Recent observations have shown that circumbinary discs can be misaligned with respect to the binary orbital plane.The lack of spherical symmetry, together with the non-planar geometry of these systems, causes differential precession which might induce the propagation of warps. While gas dynamics in such environments is well understood, little is known about dusty discs. In this work, we analytically study the problem of dust traps formation in misaligned circumbinary discs. We find that pile-ups may be induced not by pressure maxima, as the usual dust traps, but by a difference in precession rates between the gas and dust. Indeed, this difference makes the radial drift inefficient in two locations, leading to the formation of two dust rings whose position depends on the system parameters. This phenomenon is likely to occur to marginally coupled dust particles ¹St & 1º as both the effect of gravitational and drag force are considerable. We then perform a suite of three-dimensional SPH numerical simulations to compare the results with our theoretical predictions. We explore the parameter space, varying stellar mass ratio, disc thickness, radial extension, and we find a general agreement with the analytical expectations. -
Publication List for Amaury H.M.J. Triaud Most Important Publications
1 Publication List for Amaury H.M.J. Triaud Listing following SAO/NASA’s ADS paper archive. There are active links to the ADS paper archive in blue. All refereed publication can be accessed by clicking here and all publications, in- cluding conference proceedings, white papers and some proposal abstracts by clicking here. LAST UPDATED ON 2015-07-16: 101 refereed publications, above 2700 citations. H-index = 30. In addition: 4 are submitted or in press, 16 are conference proceedings or white papers. Most important publications WASP-80B HAS A DAYSIDE WITHIN THE T-DWARF RANGE Triaud, Amaury H. M. J., Gillon, Michaël, Ehrenreich, David, Herrero, Enrique, Lendl, Monika, Anderson, David R., Collier Cameron, Andrew, Delrez, Laetitia, Demory, Brice-Olivier, Hellier, Coel, Heng, Kevin, Jehin, Emmanuel, Maxted, Pierre F. L., Pollacco, Don, Queloz, Didier, Ribas, Ignasi, Smalley, Barry, Smith, Alexis M. S., Udry, Stéphane 2015 MNRAS 450 2279 CIRCUMBINARY PLANETS - WHY THEY ARE SO LIKELY TO TRANSIT Martin, D. V. & Triaud, A. H. M. J. 2015 MNRAS 449, 781 PLANETS TRANSITING NON-ECLIPSING BINARIES Martin, D. V. & Triaud, A. H. M. J. 2014 A&A 570, 91 COLOUR-MAGNITUDE DIAGRAMS OF TRANSITING EXOPLANETS I-SYSTEMS WITH PARALLAXES Triaud, A. H. M. J. 2014 MNRAS 439, L61 FAST-EVOLVING WEATHER FOR THE COOLEST OF OUR TWO NEW SUBSTELLAR NEIGHBOURS Gillon, M., Triaud, A. H. M. J., Jehin, E., Delrez, L., Opitom, C., Magain, P., Lendl, M., Queloz, D. 2013 A&A 555, L5 A SEARCH FOR ROCKY PLANETS TRANSITING BROWN DWARFS Triaud, Amaury H. M. J., Gillon, Michael, Selsis, Franck, Winn, Joshua N., Demory, Brice-Olivier, Artigau, Etienne, Laughlin, Gregory P., Seager, Sara, Helling, Christiane, Mayor, Michel, Albert, Loic, Anderson, Richard I., Bolmont, Emeline, Doyon, Rene, Forveille, Thierry, Hagelberg, Janis, Leconte, Jeremy, Lendl, Monika, Littlefair, Stuart, Raymond, Sean, Sahlmann, Johannes (arXiv:1304.7248) WASP-80B: A GAS GIANT TRANSITING A COOL DWARF Triaud, A. -
Milan Dimitrijevic Avgust.Qxd
1. M. Platiša, M. Popović, M. Dimitrijević, N. Konjević: 1975, Z. Fur Natur- forsch. 30a, 212 [A 1].* 1. Griem, H. R.: 1975, Stark Broadening, Adv. Atom. Molec. Phys. 11, 331. 2. Platiša, M., Popović, M. V., Konjević, N.: 1975, Stark broadening of O II and O III lines, Astron. Astrophys. 45, 325. 3. Konjević, N., Wiese, W. L.: 1976, Experimental Stark widths and shifts for non-hydrogenic spectral lines of ionized atoms, J. Phys. Chem. Ref. Data 5, 259. 4. Hey, J. D.: 1977, On the Stark broadening of isolated lines of F (II) and Cl (III) by plasmas, JQSRT 18, 649. 5. Hey, J. D.: 1977, Estimates of Stark broadening of some Ar III and Ar IV lines, JQSRT 17, 729. 6. Hey, J. D.: Breger, P.: 1980, Stark broadening of isolated lines emitted by singly - ionized tin, JQSRT 23, 311. 7. Hey, J. D.: Breger, P.: 1981, Stark broadening of isolated ion lines by plas- mas: Application of theory, in Spectral Line Shapes I, ed. B. Wende, W. de Gruyter, 201. 8. Сыркин, М. И.: 1981, Расчеты электронного уширения спектральных линий в теории оптических свойств плазмы, Опт. Спектроск. 51, 778. 9. Wiese, W. L., Konjević, N.: 1982, Regularities and similarities in plasma broadened spectral line widths (Stark widths), JQSRT 28, 185. 10. Konjević, N., Pittman, T. P.: 1986, Stark broadening of spectral lines of ho- mologous, doubly ionized inert gases, JQSRT 35, 473. 11. Konjević, N., Pittman, T. P.: 1987, Stark broadening of spectral lines of ho- mologous, doubly - ionized inert gases, JQSRT 37, 311. 12. Бабин, С. -
The Study of Astronomical Transients in the Infrared
The Study of Astronomical Transients in the Infrared by Robert Strausbaugh A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Approved May 2019 by the Graduate Supervisory Committee: Nathaniel Butler, Chair Rolf Jansen Phillip Mauskopf Rogier Windhorst ARIZONA STATE UNIVERSITY August 2019 ©2019 Robert Strausbaugh All Rights Reserved ABSTRACT Several key, open questions in astrophysics can be tackled by searching for and mining large datasets for transient phenomena. The evolution of massive stars and compact objects can be studied over cosmic time by identifying supernovae (SNe) and gamma-ray bursts (GRBs) in other galaxies and determining their redshifts. Modeling GRBs and their afterglows to probe the jets of GRBs can shed light on the emission mechanism, rate, and energetics of these events. In Chapter 1, I discuss the current state of astronomical transient study, including sources of interest, instrumentation, and data reduction techniques, with a focus on work in the infrared. In Chapter 2, I present original work published in the Proceedings of the Astronomical Society of the Pacific, testing InGaAs infrared detectors for astronomical use (Strausbaugh, Jackson, and Butler 2018); highlights of this work include observing the exoplanet transit of HD189773B, and detecting the nearby supernova SN2016adj with an InGaAs detector mounted on a small telescope at ASU. In Chapter 3, I discuss my work on GRB jets published in the Astrophysical Journal Letters, highlighting the interesting case of GRB 160625B (Strausbaugh et al. 2019), where I interpret a late-time bump in the GRB afterglow lightcurve as evidence for a bright-edged jet. -
Download This Article in PDF Format
A&A 609, A8 (2018) Astronomy DOI: 10.1051/0004-6361/201731453 & c ESO 2017 Astrophysics The completeness-corrected rate of stellar encounters with the Sun from the first Gaia data release? C. A. L. Bailer-Jones Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany e-mail: [email protected] Received 27 June 2017 / Accepted 12 August 2017 ABSTRACT I report on close encounters of stars to the Sun found in the first Gaia data release (GDR1). Combining Gaia astrometry with radial velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential to identify those stars which pass within a few parsecs. Such encounters could influence the solar system, for example through gravitational perturbations of the Oort cloud. 16 stars are found to come within 2 pc (although a few of these have dubious data). This is fewer than were found in a similar study based on Hipparcos data, even though the present study has many more candidates. This is partly because I reject stars with large radial velocity uncertainties (>10 km s−1), and partly because of missing stars in GDR1 (especially at the bright end). The closest encounter found is Gl 710, a K dwarf long-known to come close to the Sun in about 1.3 Myr. The Gaia astrometry predict a much closer passage than pre-Gaia estimates, however: just 16 000 AU (90% confidence interval: 10 000–21 000 AU), which will bring this star well within the Oort cloud. Using a simple model for the spatial, velocity, and luminosity distributions of stars, together with an approximation of the observational selection function, I model the incompleteness of this Gaia-based search as a function of the time and distance of closest approach. -
Meeting Program
A A S MEETING PROGRAM 211TH MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY WITH THE HIGH ENERGY ASTROPHYSICS DIVISION (HEAD) AND THE HISTORICAL ASTRONOMY DIVISION (HAD) 7-11 JANUARY 2008 AUSTIN, TX All scientific session will be held at the: Austin Convention Center COUNCIL .......................... 2 500 East Cesar Chavez St. Austin, TX 78701 EXHIBITS ........................... 4 FURTHER IN GRATITUDE INFORMATION ............... 6 AAS Paper Sorters SCHEDULE ....................... 7 Rachel Akeson, David Bartlett, Elizabeth Barton, SUNDAY ........................17 Joan Centrella, Jun Cui, Susana Deustua, Tapasi Ghosh, Jennifer Grier, Joe Hahn, Hugh Harris, MONDAY .......................21 Chryssa Kouveliotou, John Martin, Kevin Marvel, Kristen Menou, Brian Patten, Robert Quimby, Chris Springob, Joe Tenn, Dirk Terrell, Dave TUESDAY .......................25 Thompson, Liese van Zee, and Amy Winebarger WEDNESDAY ................77 We would like to thank the THURSDAY ................. 143 following sponsors: FRIDAY ......................... 203 Elsevier Northrop Grumman SATURDAY .................. 241 Lockheed Martin The TABASGO Foundation AUTHOR INDEX ........ 242 AAS COUNCIL J. Craig Wheeler Univ. of Texas President (6/2006-6/2008) John P. Huchra Harvard-Smithsonian, President-Elect CfA (6/2007-6/2008) Paul Vanden Bout NRAO Vice-President (6/2005-6/2008) Robert W. O’Connell Univ. of Virginia Vice-President (6/2006-6/2009) Lee W. Hartman Univ. of Michigan Vice-President (6/2007-6/2010) John Graham CIW Secretary (6/2004-6/2010) OFFICERS Hervey (Peter) STScI Treasurer Stockman (6/2005-6/2008) Timothy F. Slater Univ. of Arizona Education Officer (6/2006-6/2009) Mike A’Hearn Univ. of Maryland Pub. Board Chair (6/2005-6/2008) Kevin Marvel AAS Executive Officer (6/2006-Present) Gary J. Ferland Univ. of Kentucky (6/2007-6/2008) Suzanne Hawley Univ.