Astro 1: Introductory Astronomy

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Astro 1: Introductory Astronomy David Cohen Class 27: Tuesday, April 29 Spring 2014 http://apod.nasa.gov/apod/ap130927.html Andromeda Galaxy http://apod.nasa.gov/apod/ap130927.html Andromeda http://apod.nasa.gov/apod/ap130416.html M 51: The Whirlpool Galaxy http://apod.nasa.gov/apod/ap060219.html Messier 83: a (mildly) barred spiral http://apod.nasa.gov/apod/ap140128.html NGC 1300: a (signiﬁcantly) barred spiral The Hubble sequence of galaxies not nearly as explanatory/fundamental as stellar types and the HR diagram are for stars Messier 87: elliptical galaxy (with several others) http://apod.nasa.gov/apod/ap110829.html an elliptical galaxy and a spiral galaxy http://apod.nasa.gov/apod/ap120914.html Centaurus A http://apod.nasa.gov/apod/ap100313.html NGC 7049: dusty spiral that otherwise looks like an elliptical - a merger product? http://apod.nasa.gov/apod/ap090408.html Large Magellanic Cloud (irregular galaxy and near neighbor to the Milky Way) the “Magellanic Stream” - gas being pulled out of the Magellanic Clouds (our nearby neighbor galaxies) by the gravity of the Milky Way http://apod.nasa.gov/apod/ap100125.html The Hydra cluster http://apod.nasa.gov/apod/ap120512.html a galaxy is stripped of its gas as it orbits around its cluster blue is X-ray emitting hot gas http://apod.nasa.gov/apod/ap140328.html Abell 2744: huge galaxy cluster, ﬁlled with X-ray emitting gas http://apod.nasa.gov/apod/ap110629.html http://apod.nasa.gov/apod/ap130308.html The Hubble Deep Field (multi-week exposure: 1000s of galaxies): this is a relatively empty part of the sky! http://apod.nasa.gov/apod/ap121014.html.

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Messier Objects
Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun.
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Monthly Observer's Challenge
MONTHLY OBSERVER’S CHALLENGE Las Vegas Astronomical Society Compiled by: Roger Ivester, Boiling Springs, North Carolina & Fred Rayworth, Las Vegas, Nevada With special assistance from: Rob Lambert, Las Vegas, Nevada JUNE 2015 Introduction The purpose of the Observer’s Challenge is to encourage the pursuit of visual observing. It’s open to everyone that’s interested, and if you’re able to contribute notes, and/or drawings, we’ll be happy to include them in our monthly summary. We also accept digital imaging. Visual astronomy depends on what’s seen through the eyepiece. Not only does it satisfy an innate curiosity, but it allows the visual observer to discover the beauty and the wonderment of the night sky. Before photography, all observations depended on what the astronomer saw in the eyepiece, and how they recorded their observations. This was done through notes and drawings, and that’s the tradition we’re stressing in the Observers Challenge. We’re not excluding those with an interest in astrophotography, either. Your images and notes are just as welcome. The hope is that you’ll read through these reports and become inspired to take more time at the eyepiece, study each object, and look for those subtle details that you might never have noticed before. M83 – NGC-5236 The Southern Pinwheel Galaxy In Hydra M83, also known as NGC-5236, is a face-in barred spiral galaxy in the southern sky, which lies in the constellation of Hydra. Charles Messier added it to his catalogue of non-comets in March 1781, but it was actually discovered by Nicolas Louis de Lacaille on February 23, 1752 from his observatory in the Cape of Good Hope in South Africa.
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A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short).
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Rules & Requirements for an SBAS Observing Certificate 1. You Must
Rules & Requirements for an SBAS Observing Certificate 1. You must be a member of the SBAS in good standing to receive a certificate. 2. No Go To or Push To aided attempts will be accepted. Reading charts and star hopping are essential skills in our hobby. (You may use these methods to confirm your findings.) 3. Honor system is in full effect. These lists benefit your knowledge of the sky. Cheating only cheats yourself and the SBAS membership. Observations will be verified against digital planetarium charts. You may be required to answer questions about the objects you observed to verify your work. You may also be asked to show one of these objects at a star party. Once a list is completed, it is assumed you are familiar with every object on that list to the point where you can find it again and describe it to another person. 4. Upon completion of a list, submit the original paper version in person to Coy Wagoner at an SBAS meeting, public star party, or informal observing at the Worley. No digital submissions will be accepted at this time. 5. No observations may overlap. If one object is on two lists, your observations must be done on separate dates/times for credit. Copies of your observing logs will be saved and later compared to additional lists to make sure nothing overlaps. No observations prior to January 1, 2015 will be accepted for credit. 6. Observations should be done on your own. If you observe an object in someone else’s telescope or binoculars, the observation does not count unless you did the work to find it.
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The Messier Catalog
The Messier Catalog Messier 1 Messier 2 Messier 3 Messier 4 Messier 5 Crab Nebula globular cluster globular cluster globular cluster globular cluster Messier 6 Messier 7 Messier 8 Messier 9 Messier 10 open cluster open cluster Lagoon Nebula globular cluster globular cluster Butterfly Cluster Ptolemy's Cluster Messier 11 Messier 12 Messier 13 Messier 14 Messier 15 Wild Duck Cluster globular cluster Hercules glob luster globular cluster globular cluster Messier 16 Messier 17 Messier 18 Messier 19 Messier 20 Eagle Nebula The Omega, Swan, open cluster globular cluster Trifid Nebula or Horseshoe Nebula Messier 21 Messier 22 Messier 23 Messier 24 Messier 25 open cluster globular cluster open cluster Milky Way Patch open cluster Messier 26 Messier 27 Messier 28 Messier 29 Messier 30 open cluster Dumbbell Nebula globular cluster open cluster globular cluster Messier 31 Messier 32 Messier 33 Messier 34 Messier 35 Andromeda dwarf Andromeda Galaxy Triangulum Galaxy open cluster open cluster elliptical galaxy Messier 36 Messier 37 Messier 38 Messier 39 Messier 40 open cluster open cluster open cluster open cluster double star Winecke 4 Messier 41 Messier 42/43 Messier 44 Messier 45 Messier 46 open cluster Orion Nebula Praesepe Pleiades open cluster Beehive Cluster Suburu Messier 47 Messier 48 Messier 49 Messier 50 Messier 51 open cluster open cluster elliptical galaxy open cluster Whirlpool Galaxy Messier 52 Messier 53 Messier 54 Messier 55 Messier 56 open cluster globular cluster globular cluster globular cluster globular cluster Messier 57 Messier
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Further Definition of the Mass-Metallicity Relation In
Further Definition of the Mass-Metallicity Relation in Globular Cluster Systems Around Brightest Cluster Galaxies Robert Cockcroft Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada [email protected] William E. Harris Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada [email protected] Elizabeth M. H. Wehner Utrecht University, PO Box 80125, 3508 TC Utrecht, The Netherlands [email protected] Bradley C. Whitmore Space Telescope Science Institute, 3700 San Martin Drive, Baltimore MD 21218 [email protected] and Barry Rothberg arXiv:0906.2008v1 [astro-ph.CO] 10 Jun 2009 Naval Research Laboratory, Code 7211, 4555 Overlook Ave SW, Washington D.C. 20375 [email protected] ABSTRACT We combine the globular cluster data for fifteen Brightest Cluster Galaxies and use this material to trace the mass-metallicity relations (MMR) in their glob- ular cluster systems (GCSs). This work extends previous studies which correlate the properties of the MMR with those of the host galaxy. Our combined data sets –2– show a mean trend for the metal-poor (MP) subpopulation which corresponds to a scaling of heavy-element abundance with cluster mass Z ∼ M0.30±0.05. No trend is seen for the metal-rich (MR) subpopulation which has a scaling relation that is consistent with zero. We also find that the scaling exponent is independent of the GCS specific frequency and host galaxy luminosity, except perhaps for dwarf galaxies. We present new photometry in (g’,i’) obtained with Gemini/GMOS for the globular cluster populations around the southern giant ellipticals NGC 5193 and IC 4329.
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The Recent Star Formation in Sextans a Schuyler D
THE ASTRONOMICAL JOURNAL, 116:2341È2362, 1998 November ( 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE RECENT STAR FORMATION IN SEXTANS A SCHUYLER D. VAN DYK1 Infrared Processing and Analysis Center, California Institute of Technology, Mail Code 100-22, Pasadena, CA 91125; vandyk=ipac.caltech.edu DANIEL PUCHE1 Tellabs Transport Group, Inc., 3403 Griffith Street, Ville St. Laurent, Montreal, Quebec H4T 1W5, Canada; Daniel.Puche=tellabs.com AND TONY WONG1 Department of Astronomy, University of California at Berkeley, 601 Cambell Hall, Berkeley, CA 94720-3411; twong=astro.berkeley.edu Received 5 February 1998; revised 1998 July 8 ABSTRACT We investigate the relationship between the spatial distributions of stellar populations and of neutral and ionized gas in the Local Group dwarf irregular galaxy Sextans A. This galaxy is currently experi- encing a burst of localized star formation, the trigger of which is unknown. We have resolved various populations of stars via deepUBV (RI) imaging over an area with [email protected]. We have compared our photometry with theoretical isochronesC appropriate for Sextans A, in order to determine the ages of these populations. We have mapped out the history of star formation, most accurately for times [100 Myr. We Ðnd that star formation in Sextans A is correlated both in time and space, especially for the most recent([12 Myr) times. The youngest stars in the galaxy are forming primarily along the inner edge of the large H I shell. Somewhat older populations,[50 Myr, are found inward of the youngest stars. Progressively older star formation, from D50È100 Myr, appears to have some spatially coherent structure and is more centrally concentrated.
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X-Ray Luminosities for a Magnitude-Limited Sample of Early-Type Galaxies from the ROSAT All-Sky Survey
Mon. Not. R. Astron. Soc. 302, 209±221 (1999) X-ray luminosities for a magnitude-limited sample of early-type galaxies from the ROSAT All-Sky Survey J. Beuing,1* S. DoÈbereiner,2 H. BoÈhringer2 and R. Bender1 1UniversitaÈts-Sternwarte MuÈnchen, Scheinerstrasse 1, D-81679 MuÈnchen, Germany 2Max-Planck-Institut fuÈr Extraterrestrische Physik, D-85740 Garching bei MuÈnchen, Germany Accepted 1998 August 3. Received 1998 June 1; in original form 1997 December 30 Downloaded from https://academic.oup.com/mnras/article/302/2/209/968033 by guest on 30 September 2021 ABSTRACT For a magnitude-limited optical sample (BT # 13:5 mag) of early-type galaxies, we have derived X-ray luminosities from the ROSATAll-Sky Survey. The results are 101 detections and 192 useful upper limits in the range from 1036 to 1044 erg s1. For most of the galaxies no X-ray data have been available until now. On the basis of this sample with its full sky coverage, we ®nd no galaxy with an unusually low ¯ux from discrete emitters. Below log LB < 9:2L( the X-ray emission is compatible with being entirely due to discrete sources. Above log LB < 11:2L( no galaxy with only discrete emission is found. We further con®rm earlier ®ndings that Lx is strongly correlated with LB. Over the entire data range the slope is found to be 2:23 60:12. We also ®nd a luminosity dependence of this correlation. Below 1 log Lx 40:5 erg s it is consistent with a slope of 1, as expected from discrete emission.
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NASA Teacher Science Background Q&A
National Aeronautics and Space Administration Science Teacher’s Background SciGALAXY Q&As NASA / Amazing Space Science Background: Galaxy Q&As 1. What is a galaxy? A galaxy is an enormous collection of a few million to several trillion stars, gas, and dust held together by gravity. Galaxies can be several thousand to hundreds of thousands of light-years across. 2. What is the name of our galaxy? The name of our galaxy is the Milky Way. Our Sun and all of the stars that you see at night belong to the Milky Way. When you go outside in the country on a dark night and look up, you will see a milky, misty-looking band stretching across the sky. When you look at this band, you are looking into the densest parts of the Milky Way — the “disk” and the “bulge.” The Milky Way is a spiral galaxy. (See Q7 for more on spiral galaxies.) 3. Where is Earth in the Milky Way galaxy? Our solar system is in one of the spiral arms of the Milky Way, called the Orion Arm, and is about two-thirds of the way from the center of the galaxy to the edge of the galaxy’s starlight. Earth is the third planet from the Sun in our solar system of eight planets. 4. What is the closest galaxy that is similar to our own galaxy, and how far away is it? The closest spiral galaxy is Andromeda, a galaxy much like our own Milky Way. It is 2. million light-years away from us.
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Astronomy and Astrophysics Books in Print, and to Choose Among Them Is a Difficult Task
APPENDIX ONE Degeneracy Degeneracy is a very complex topic but a very important one, especially when discussing the end stages of a star’s life. It is, however, a topic that sends quivers of apprehension down the back of most people. It has to do with quantum mechanics, and that in itself is usually enough for most people to move on, and not learn about it. That said, it is actually quite easy to understand, providing that the information given is basic and not peppered throughout with mathematics. This is the approach I shall take. In most stars, the gas of which they are made up will behave like an ideal gas, that is, one that has a simple relationship among its temperature, pressure, and density. To be specific, the pressure exerted by a gas is directly proportional to its temperature and density. We are all familiar with this. If a gas is compressed, it heats up; likewise, if it expands, it cools down. This also happens inside a star. As the temperature rises, the core regions expand and cool, and so it can be thought of as a safety valve. However, in order for certain reactions to take place inside a star, the core is compressed to very high limits, which allows very high temperatures to be achieved. These high temperatures are necessary in order for, say, helium nuclear reactions to take place. At such high temperatures, the atoms are ionized so that it becomes a soup of atomic nuclei and electrons. Inside stars, especially those whose density is approaching very high values, say, a white dwarf star or the core of a red giant, the electrons that make up the central regions of the star will resist any further compression and themselves set up a powerful pressure.1 This is termed degeneracy, so that in a low-mass red 191 192 Astrophysics is Easy giant star, for instance, the electrons are degenerate, and the core is supported by an electron-degenerate pressure.
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Index to JRASC Volumes 61-90 (PDF)
THE ROYAL ASTRONOMICAL SOCIETY OF CANADA GENERAL INDEX to the JOURNAL 1967–1996 Volumes 61 to 90 inclusive (including the NATIONAL NEWSLETTER, NATIONAL NEWSLETTER/BULLETIN, and BULLETIN) Compiled by Beverly Miskolczi and David Turner* * Editor of the Journal 1994–2000 Layout and Production by David Lane Published by and Copyright 2002 by The Royal Astronomical Society of Canada 136 Dupont Street Toronto, Ontario, M5R 1V2 Canada www.rasc.ca — [email protected] Table of Contents Preface ....................................................................................2 Volume Number Reference ...................................................3 Subject Index Reference ........................................................4 Subject Index ..........................................................................7 Author Index ..................................................................... 121 Abstracts of Papers Presented at Annual Meetings of the National Committee for Canada of the I.A.U. (1967–1970) and Canadian Astronomical Society (1971–1996) .......................................................................168 Abstracts of Papers Presented at the Annual General Assembly of the Royal Astronomical Society of Canada (1969–1996) ...........................................................207 JRASC Index (1967-1996) Page 1 PREFACE The last cumulative Index to the Journal, published in 1971, was compiled by Ruth J. Northcott and assembled for publication by Helen Sawyer Hogg. It included all articles published in the Journal during the interval 1932–1966, Volumes 26–60. In the intervening years the Journal has undergone a variety of changes. In 1970 the National Newsletter was published along with the Journal, being bound with the regular pages of the Journal. In 1978 the National Newsletter was physically separated but still included with the Journal, and in 1989 it became simply the Newsletter/Bulletin and in 1991 the Bulletin. That continued until the eventual merger of the two publications into the new Journal in 1997.
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Lesson 5 Galaxies and Beyond
LESSON 5 GALAXIES AND BEYOND Chapter 8 Astronomy OBJECTIVES • Classify galaxies according to their properties. • Explain the big bang and the way in which Earth and its atmosphere were formed. MAIN IDEA The Milky Way is one of billions of galaxies that are moving away from each other in an expanding universe. VOCABULARY • galaxy • Milky Way • spectrum • expansion redshift • big bang • background radiation WHAT ARE GALAXIES? • A galaxy is a group of star clusters held together by gravity. • Stars move around the center of their galaxy in the same way that planets orbit a star. • Galaxies differ in size, age, and structure. • Astronomers place them in three main groups based on shape. • spiral • elliptical • irregular SPIRAL GALAXY • Spiral galaxies look like whirlpools. • Some are barred spiral galaxies. • Have bars of stars, gas, and dust throughout its center. • Spiral arms emerge from this bar. ELLIPTICAL GALAXY • An elliptical galaxy is shaped a bit like a football. • It has no spiral arms and little or no dust. IRREGULAR GALAXY • Has no recognizable shape. • The amount of dust varies. • Collisions with other galaxies may have caused the irregular shape. THE MILKY WAY GALAXY • During the summer at night, overhead, you will see a broad band of light stretching across the sky. • You are looking at part of the Milky Way. • The Milky Way is our home galaxy. • The Milky Way is a spiral galaxy. • The stars are grouped in a bulge around a core. • All of the stars in the Milky Way including our sun orbit this core. • The closer a star is to the core the faster its orbit.
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