The Cosmic Distance Scale • Distance Information Is Often Crucial to Understand the Physics of Astrophysical Objects
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Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold
Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page Journal of Double Star Observations VOLUME 9 NUMBER 2 April 1, 2013 Inside this issue: Using VizieR/Aladin to Measure Neglected Double Stars 75 Richard Harshaw BN Orionis (TYC 126-0781-1) Duplicity Discovery from an Asteroidal Occultation by (57) Mnemosyne 88 Tony George, Brad Timerson, John Brooks, Steve Conard, Joan Bixby Dunham, David W. Dunham, Robert Jones, Thomas R. Lipka, Wayne Thomas, Wayne H. Warren Jr., Rick Wasson, Jan Wisniewski Study of a New CPM Pair 2Mass 14515781-1619034 96 Israel Tejera Falcón Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold HJ 4217 - Now a Known Unknown 107 Graeme L. White and Roderick Letchford Double Star Measures Using the Video Drift Method - III 113 Richard L. Nugent, Ernest W. Iverson A New Common Proper Motion Double Star in Corvus 122 Abdul Ahad High Speed Astrometry of STF 2848 With a Luminera Camera and REDUC Software 124 Russell M. Genet TYC 6223-00442-1 Duplicity Discovery from Occultation by (52) Europa 130 Breno Loureiro Giacchini, Brad Timerson, Tony George, Scott Degenhardt, Dave Herald Visual and Photometric Measurements of a Selected Set of Double Stars 135 Nathan Johnson, Jake Shellenberger, Elise Sparks, Douglas Walker A Pixel Correlation Technique for Smaller Telescopes to Measure Doubles 142 E. O. Wiley Double Stars at the IAU GA 2012 153 Brian D. Mason Report on the Maui International Double Star Conference 158 Russell M. Genet International Association of Double Star Observers (IADSO) 170 Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page 75 Using VizieR/Aladin to Measure Neglected Double Stars Richard Harshaw Cave Creek, Arizona [email protected] Abstract: The VizierR service of the Centres de Donnes Astronomiques de Strasbourg (France) offers amateur astronomers a treasure trove of resources, including access to the most current version of the Washington Double Star Catalog (WDS) and links to tens of thousands of digitized sky survey plates via the Aladin Java applet. -
Plotting Variable Stars on the H-R Diagram Activity
Pulsating Variable Stars and the Hertzsprung-Russell Diagram The Hertzsprung-Russell (H-R) Diagram: The H-R diagram is an important astronomical tool for understanding how stars evolve over time. Stellar evolution can not be studied by observing individual stars as most changes occur over millions and billions of years. Astrophysicists observe numerous stars at various stages in their evolutionary history to determine their changing properties and probable evolutionary tracks across the H-R diagram. The H-R diagram is a scatter graph of stars. When the absolute magnitude (MV) – intrinsic brightness – of stars is plotted against their surface temperature (stellar classification) the stars are not randomly distributed on the graph but are mostly restricted to a few well-defined regions. The stars within the same regions share a common set of characteristics. As the physical characteristics of a star change over its evolutionary history, its position on the H-R diagram The H-R Diagram changes also – so the H-R diagram can also be thought of as a graphical plot of stellar evolution. From the location of a star on the diagram, its luminosity, spectral type, color, temperature, mass, age, chemical composition and evolutionary history are known. Most stars are classified by surface temperature (spectral type) from hottest to coolest as follows: O B A F G K M. These categories are further subdivided into subclasses from hottest (0) to coolest (9). The hottest B stars are B0 and the coolest are B9, followed by spectral type A0. Each major spectral classification is characterized by its own unique spectra. -
V. Spatially-Resolved Stellar Angular Momentum, Velocity Dispersion, and Higher Moments of the 41 Most Massive Local Early-Type Galaxies
MNRAS 000,1{20 (2016) Preprint 9 September 2016 Compiled using MNRAS LATEX style file v3.0 The MASSIVE Survey - V. Spatially-Resolved Stellar Angular Momentum, Velocity Dispersion, and Higher Moments of the 41 Most Massive Local Early-Type Galaxies Melanie Veale,1;2 Chung-Pei Ma,1 Jens Thomas,3 Jenny E. Greene,4 Nicholas J. McConnell,5 Jonelle Walsh,6 Jennifer Ito,1 John P. Blakeslee,5 Ryan Janish2 1Department of Astronomy, University of California, Berkeley, CA 94720, USA 2Department of Physics, University of California, Berkeley, CA 94720, USA 3Max Plank-Institute for Extraterrestrial Physics, Giessenbachstr. 1, D-85741 Garching, Germany 4Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA 5Dominion Astrophysical Observatory, NRC Herzberg Institute of Astrophysics, Victoria BC V9E2E7, Canada 6George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, and Department of Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We present spatially-resolved two-dimensional stellar kinematics for the 41 most mas- ∗ 11:8 sive early-type galaxies (MK . −25:7 mag, stellar mass M & 10 M ) of the volume-limited (D < 108 Mpc) MASSIVE survey. For each galaxy, we obtain high- quality spectra in the wavelength range of 3650 to 5850 A˚ from the 246-fiber Mitchell integral-field spectrograph (IFS) at McDonald Observatory, covering a 10700 × 10700 field of view (often reaching 2 to 3 effective radii). We measure the 2-D spatial distri- bution of each galaxy's angular momentum (λ and fast or slow rotator status), velocity dispersion (σ), and higher-order non-Gaussian velocity features (Gauss-Hermite mo- ments h3 to h6). -
KEPLER-21B: a 1.6 Rearth PLANET TRANSITING the BRIGHT OSCILLATING F SUBGIANT STAR HD 179070 Steve B
The Astrophysical Journal, 746:123 (18pp), 2012 February 20 doi:10.1088/0004-637X/746/2/123 C 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A. ∗ KEPLER-21b: A 1.6 REarth PLANET TRANSITING THE BRIGHT OSCILLATING F SUBGIANT STAR HD 179070 Steve B. Howell1,2,36, Jason F. Rowe2,3,36, Stephen T. Bryson2, Samuel N. Quinn4, Geoffrey W. Marcy5, Howard Isaacson5, David R. Ciardi6, William J. Chaplin7, Travis S. Metcalfe8, Mario J. P. F. G. Monteiro9, Thierry Appourchaux10, Sarbani Basu11, Orlagh L. Creevey12,13, Ronald L. Gilliland14, Pierre-Olivier Quirion15, Denis Stello16, Hans Kjeldsen17,Jorgen¨ Christensen-Dalsgaard17, Yvonne Elsworth7, Rafael A. Garc´ıa18, Gunter¨ Houdek19, Christoffer Karoff7, Joanna Molenda-Zakowicz˙ 20, Michael J. Thompson8, Graham A. Verner7,21, Guillermo Torres4, Francois Fressin4, Justin R. Crepp23, Elisabeth Adams4, Andrea Dupree4, Dimitar D. Sasselov4, Courtney D. Dressing4, William J. Borucki2, David G. Koch2, Jack J. Lissauer2, David W. Latham4, Lars A. Buchhave22,35, Thomas N. Gautier III24, Mark Everett1, Elliott Horch25, Natalie M. Batalha26, Edward W. Dunham27, Paula Szkody28,36, David R. Silva1,36, Ken Mighell1,36, Jay Holberg29,36,Jeromeˆ Ballot30, Timothy R. Bedding16, Hans Bruntt12, Tiago L. Campante9,17, Rasmus Handberg17, Saskia Hekker7, Daniel Huber16, Savita Mathur8, Benoit Mosser31, Clara Regulo´ 12,13, Timothy R. White16, Jessie L. Christiansen3, Christopher K. Middour32, Michael R. Haas2, Jennifer R. Hall32,JonM.Jenkins3, Sean McCaulif32, Michael N. Fanelli33, Craig -
Experiencing Hubble
PRESCOTT ASTRONOMY CLUB PRESENTS EXPERIENCING HUBBLE John Carter August 7, 2019 GET OUT LOOK UP • When Galaxies Collide https://www.youtube.com/watch?v=HP3x7TgvgR8 • How Hubble Images Get Color https://www.youtube.com/watch? time_continue=3&v=WSG0MnmUsEY Experiencing Hubble Sagittarius Star Cloud 1. 12,000 stars 2. ½ percent of full Moon area. 3. Not one star in the image can be seen by the naked eye. 4. Color of star reflects its surface temperature. Eagle Nebula. M 16 1. Messier 16 is a conspicuous region of active star formation, appearing in the constellation Serpens Cauda. This giant cloud of interstellar gas and dust is commonly known as the Eagle Nebula, and has already created a cluster of young stars. The nebula is also referred to the Star Queen Nebula and as IC 4703; the cluster is NGC 6611. With an overall visual magnitude of 6.4, and an apparent diameter of 7', the Eagle Nebula's star cluster is best seen with low power telescopes. The brightest star in the cluster has an apparent magnitude of +8.24, easily visible with good binoculars. A 4" scope reveals about 20 stars in an uneven background of fainter stars and nebulosity; three nebulous concentrations can be glimpsed under good conditions. Under very good conditions, suggestions of dark obscuring matter can be seen to the north of the cluster. In an 8" telescope at low power, M 16 is an impressive object. The nebula extends much farther out, to a diameter of over 30'. It is filled with dark regions and globules, including a peculiar dark column and a luminous rim around the cluster. -
MODEST-18: Dense Stellar Systems in the Era of Gaia, LIGO and LISA June 25 - 29, 2018 | Santorini, Greece
MODEST-18: Dense Stellar Systems in the Era of Gaia, LIGO and LISA June 25 - 29, 2018 | Santorini, Greece POSTER Federico Abbate (Milano-Bicocca): Ionized Gas in 47 Tuc – A Detailed Study with Millisecond Pulsars Globular clusters are known to be very poor in gas despite predictions telling us otherwise. The presence of ionized gas can be investigated through its dispersive effects on the radiation of the millisecond pulsars inside the clusters. This effect led to the first detection of any kind of gas in a globular cluster in the form of ionized gas in 47 Tucanae. With new timing results of these pulsars over longer periods of time we can improve the precision of this measurement and test different distribution models. We first use the parameters measured through timing to measure the dynamical properties of the cluster and the line of sight position of the pulsars. Then we test for gas distribution models. We detect ionized gas distributed with a constant density of n = (0.22 ± 0.05) cm−3. Models predicting a decreasing density or following the stellar distribution are highly disfavoured. Thanks to the quality of the data we are also able to test for the presence of an intermediate mass black hole in the center of the cluster and we derive an upper limit for the mass at ∼ 4000 M_sun. 1 MODEST-18: Dense Stellar Systems in the Era of Gaia, LIGO and LISA June 25 - 29, 2018 | Santorini, Greece POSTER Javier Alonso-García (Antofagasta): VVV and VVV-X Surveys – Unveiling the Innermost Galaxy We find the densest concentrations of field stars in our Galaxy when we look towards its central regions. -
The Kepler Characterization of the Variability Among A- and F-Type Stars I
A&A 534, A125 (2011) Astronomy DOI: 10.1051/0004-6361/201117368 & c ESO 2011 Astrophysics The Kepler characterization of the variability among A- and F-type stars I. General overview K. Uytterhoeven1,2,3,A.Moya4, A. Grigahcène5,J.A.Guzik6, J. Gutiérrez-Soto7,8,9, B. Smalley10, G. Handler11,12, L. A. Balona13,E.Niemczura14, L. Fox Machado15,S.Benatti16,17, E. Chapellier18, A. Tkachenko19, R. Szabó20, J. C. Suárez7,V.Ripepi21, J. Pascual7, P. Mathias22, S. Martín-Ruíz7,H.Lehmann23, J. Jackiewicz24,S.Hekker25,26, M. Gruberbauer27,11,R.A.García1, X. Dumusque5,28,D.Díaz-Fraile7,P.Bradley29, V. Antoci11,M.Roth2,B.Leroy8, S. J. Murphy30,P.DeCat31, J. Cuypers31, H. Kjeldsen32, J. Christensen-Dalsgaard32 ,M.Breger11,33, A. Pigulski14, L. L. Kiss20,34, M. Still35, S. E. Thompson36,andJ.VanCleve36 (Affiliations can be found after the references) Received 30 May 2011 / Accepted 29 June 2011 ABSTRACT Context. The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. Aims. We present a first general characterization of the pulsational behaviour of A-F type stars as observed in the Kepler light curves of a sample of 750 candidate A-F type stars, and observationally investigate the relation between γ Doradus (γ Dor), δ Scuti (δ Sct), and hybrid stars. Methods. We compile a database of physical parameters for the sample stars from the literature and new ground-based observations. We analyse the Kepler light curve of each star and extract the pulsational frequencies using different frequency analysis methods. -
Astronomy 422
Astronomy 422 Lecture 15: Expansion and Large Scale Structure of the Universe Key concepts: Hubble Flow Clusters and Large scale structure Gravitational Lensing Sunyaev-Zeldovich Effect Expansion and age of the Universe • Slipher (1914) found that most 'spiral nebulae' were redshifted. • Hubble (1929): "Spiral nebulae" are • other galaxies. – Measured distances with Cepheids – Found V=H0d (Hubble's Law) • V is called recessional velocity, but redshift due to stretching of photons as Universe expands. • V=H0D is natural result of uniform expansion of the universe, and also provides a powerful distance determination method. • However, total observed redshift is due to expansion of the universe plus a galaxy's motion through space (peculiar motion). – For example, the Milky Way and M31 approaching each other at 119 km/s. • Hubble Flow : apparent motion of galaxies due to expansion of space. v ~ cz • Cosmological redshift: stretching of photon wavelength due to expansion of space. Recall relativistic Doppler shift: Thus, as long as H0 constant For z<<1 (OK within z ~ 0.1) What is H0? Main uncertainty is distance, though also galaxy peculiar motions play a role. Measurements now indicate H0 = 70.4 ± 1.4 (km/sec)/Mpc. Sometimes you will see For example, v=15,000 km/s => D=210 Mpc = 150 h-1 Mpc. Hubble time The Hubble time, th, is the time since Big Bang assuming a constant H0. How long ago was all of space at a single point? Consider a galaxy now at distance d from us, with recessional velocity v. At time th ago it was at our location For H0 = 71 km/s/Mpc Large scale structure of the universe • Density fluctuations evolve into structures we observe (galaxies, clusters etc.) • On scales > galaxies we talk about Large Scale Structure (LSS): – groups, clusters, filaments, walls, voids, superclusters • To map and quantify the LSS (and to compare with theoretical predictions), we use redshift surveys. -
REDSHIFTS and VELOCITY DISPERSIONS of GALAXY CLUSTERS in the HOROLOGIUM-RETICULUM SUPERCLUSTER Matthew C
The Astronomical Journal, 131:1280–1287, 2006 March A # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. REDSHIFTS AND VELOCITY DISPERSIONS OF GALAXY CLUSTERS IN THE HOROLOGIUM-RETICULUM SUPERCLUSTER Matthew C. Fleenor, James A. Rose, and Wayne A. Christiansen Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599; fl[email protected], [email protected], [email protected] Melanie Johnston-Hollitt Department of Physics, University of Tasmania, Hobart, TAS 7005, Australia; [email protected] Richard W. Hunstead School of Physics, University of Sydney, Sydney, NSW 2006, Australia; [email protected] Michael J. Drinkwater Department of Physics, University of Queensland, Brisbane, QLD 4072, Australia; [email protected] and William Saunders Anglo-Australian Observatory, Epping, NSW 1710, Australia; [email protected] Received 2005 October 18; accepted 2005 November 15 ABSTRACT We present 118 new optical redshifts for galaxies in 12 clusters in the Horologium-Reticulum supercluster (HRS) of galaxies. For 76 galaxies, the data were obtained with the Dual Beam Spectrograph on the 2.3 m telescope of the Australian National University at Siding Spring Observatory. After combining 42 previously unpublished redshifts with our new sample, we determine mean redshifts and velocity dispersions for 13 clusters in which previous observa- tional data were sparse. In 6 of the 13 clusters, the newly determined mean redshifts differ by more than 750 km sÀ1 from the published values. In three clusters, A3047, A3109, and A3120, the redshift data indicate the presence of multiple components along the line of sight. -
5. Cosmic Distance Ladder Ii: Standard Candles
5. COSMIC DISTANCE LADDER II: STANDARD CANDLES EQUIPMENT Computer with internet connection GOALS In this lab, you will learn: 1. How to use RR Lyrae variable stars to measures distances to objects within the Milky Way galaxy. 2. How to use Cepheid variable stars to measure distances to nearby galaxies. 3. How to use Type Ia supernovae to measure distances to faraway galaxies. 1 BACKGROUND A. MAGNITUDES Astronomers use apparent magnitudes , which are often referred to simply as magnitudes, to measure brightness: The more negative the magnitude, the brighter the object. The more positive the magnitude, the fainter the object. In the following tutorial, you will learn how to measure, or photometer , uncalibrated magnitudes: http://skynet.unc.edu/ASTR101L/videos/photometry/ 2 In Afterglow, go to “File”, “Open Image(s)”, “Sample Images”, “Astro 101 Lab”, “Lab 5 – Standard Candles”, “CD-47” and open the image “CD-47 8676”. Measure the uncalibrated magnitude of star A: uncalibrated magnitude of star A: ____________________ Uncalibrated magnitudes are always off by a constant and this constant varies from image to image, depending on observing conditions among other things. To calibrate an uncalibrated magnitude, one must first measure this constant, which we do by photometering a reference star of known magnitude: uncalibrated magnitude of reference star: ____________________ 3 The known, true magnitude of the reference star is 12.01. Calculate the correction constant: correction constant = true magnitude of reference star – uncalibrated magnitude of reference star correction constant: ____________________ Finally, calibrate the uncalibrated magnitude of star A by adding the correction constant to it: calibrated magnitude = uncalibrated magnitude + correction constant calibrated magnitude of star A: ____________________ The true magnitude of star A is 13.74. -
New Globular Cluster Age Estimates and Constraints on the Cosmic Equation of State and the Matter Density of the Universe
1 New Globular Cluster Age Estimates and Constraints on the Cosmic Equation of State and The Matter Density of the Universe. Lawrence M. Krauss* & Brian Chaboyer *Departments of Physics and Astronomy, Case Western Reserve University, 10900 Euclid Ave., Cleveland OH USA 44106-7079; Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH. USA New estimates of globular cluster distances, combined with revised ranges for input parameters in stellar evolution codes and recent estimates of the earliest redshift of cluster formation allow us to derive a new 95% confidence level lower limit on the age of the Universe of 11 Gyr. This is now definitively inconsistent with the expansion age for a flat Universe for the currently allowed range of the Hubble constant unless the cosmic equation of state is dominated by a component that violates the strong energy condition. This solidifies the case for a dark energy-dominated universe, complementing supernova data and direct measurements of the geometry and matter density in the Universe. The best-fit age is consistent with a cosmological constant-dominated (w=pressure/energy density = -1) universe. For the Hubble Key project best fit value of the Hubble Ω Constant our age limits yields the constraints w < -0.4 and Ωmatter < 0.38 at the 68 Ω % confidence level, and w < -0.26 and Ωmatter < 0.58 at the 95 % confidence level. Age determinations of globular clusters provided one of the earliest motivations for considering the possible existence of a cosmological constant. By comparing a lower limit on the age of the oldest globular clusters in our galaxy--- estimated in the 1980 s to be 15-20 Gyr---with the expansion age, determined by measurements of the Hubble constant, an apparent inconsistency arose: globular clusters appeared to be older than 2 the Universe unless one allowed for a possible Cosmological Constant. -
Exoplanet Community Report
JPL Publication 09‐3 Exoplanet Community Report Edited by: P. R. Lawson, W. A. Traub and S. C. Unwin National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, California March 2009 The work described in this publication was performed at a number of organizations, including the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). Publication was provided by the Jet Propulsion Laboratory. Compiling and publication support was provided by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement by the United States Government, or the Jet Propulsion Laboratory, California Institute of Technology. © 2009. All rights reserved. The exoplanet community’s top priority is that a line of probeclass missions for exoplanets be established, leading to a flagship mission at the earliest opportunity. iii Contents 1 EXECUTIVE SUMMARY.................................................................................................................. 1 1.1 INTRODUCTION...............................................................................................................................................1 1.2 EXOPLANET FORUM 2008: THE PROCESS OF CONSENSUS BEGINS.....................................................2