DOCSLIB.ORG

195 9Apj. . .130. .629B the HERCULES CLUSTER OF

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
195 9Apj. . .130. .629B the HERCULES CLUSTER OF .629B THE HERCULES CLUSTER OF NEBULAE* .130. G. R. Burbidge and E. Margaret Burbidge 9ApJ. Yerkes and McDonald Observatories Received March 26, 1959 195 ABSTRACT The northern of two clusters of nebulae in Hercules, first listed by Shapley in 1933, is an irregular group of about 75 bright nebulae and a larger number of faint ones, distributed over an area about Io X 40'. A set of plates of parts of this cluster, taken by Dr. Walter Baade with the 200-inch Hale reflector, is shown and described. More than three-quarters of the bright nebulae have been classified, and, of these, 69 per cent are spirals or irregulars and 31 per cent elliptical or SO. Radial velocities for 7 nebulae were obtained by Humason, and 10 have been obtained by us with the 82-inch reflector. The mean red shift is 10775 km/sec. From this sample, the total kinetic energy of the nebulae has been esti- mated. By measuring the distances between all pairs on a 48-inch Schmidt enlargement, the total poten- tial energy has been estimated. From these results it is concluded that, if the cluster is to be in a stationary state, the average galactic mass must be ^1012Mo. Three possibilities are discussed: that the masses are indeed as large as this, that there is a large amount of intergalactic matter, and that the cluster is expanding. The data for the Coma and Virgo clusters are also reviewed. It is concluded that both the Hercules and the Virgo clusters are probably expanding, but the situation is uncertain in the case of the Coma cluster. Some discussion of the implication of these results is given. I. INTRODUCTION The clustering tendency of nebulae is well established. Clusters are of all sizes, ranging from those containing very few nebulae up to the rich clusters with hundreds or thousands of members. Rich clusters may have a high degree of central concentration, or they may contain a large number of members spread over a considerable area of the sky with a less steep gradient of density within the cluster. Clearly, this clustering tendency of nebulae is of the greatest cosmologie significance, though only a few results have as yet been obtained which bear at all on the fundamental questions associated with the origin and evolution of those clusters. Of the rich compact clusters, a number have been studied in the last twenty years by the method of making counts, by Zwicky and his collaborators (1941, 1942a, b, 1951, 1957), Shane and Wirtanen (1954), and Omer (1952). These include the Coma, Hydra, Cancer, and Pegasus clusters. Zwicky has shown that the density distribution of the nebulae in some of the clusters is that of an isothermal gravitational gas sphere (with a cutoff). In the inner parts of such clusters the distribution of the nebulae is highly symmetrical. If these clusters are stationary, then it is possible to use the virial theorem to determine the relation between the velocity dispersion of the cluster members and the total mass of the cluster and hence the average masses of cluster members. We shall discuss results which have been obtained in this way in Section III. Suffice it to remark here that the values obtained by Zwicky are often unrealistic, since he has never accepted any of the revisions in the distance scale since Hubble’s (1936) value of the red-shift constant of 526 km/sec per 106 pc. Besides the rich compact clusters, a large number of irregular clusters are also known. The first list of these was given by Shapley (1933). The best known is the Virgo cluster because it is so near and so conspicuous to us. Apart from this cluster, none of the irregular systems have, to our knowledge, been studied in detail. The Hercules cluster, which was first brought to our attention by W. Baade, falls into this category. It has been listed by Abell (1958) (No. 2151 in his catalogue), and there is another irregular cluster, Abell No. 2152, 1?3 south of it. Abell has put No. 2151 in richness category * Contributions from the McDonald Observatory, No. 310. 629 © American Astronomical Society • Provided by the NASA Astrophysics Data System .629B 630 G. R. BURBIDGE AND E. MARGARET BURBIDGE .130. 2, which means that it contains between 80 and 129 members down to 2 mag. fainter 9ApJ. than the third brightest member. Shapley (1933) also listed a cluster at this position (No. 15) but gives its membership as 256 down to the plate limit of 17.4 apparent photo- 195 graphic magnitude. With the necessary revision in the magnitude scale, this limit must be fainter than 17.4, but we have not estimated by how much. We have made counts on an enlargement from the original Palomar 48-inch Schmidt plate (red-sensitive) which was obtained for the Sky Survey. This is reproduced in Figure 1. Down to the faintest object that could be seen, we counted 242 nebulae, of which most of the faint ones must be field nebulae. Down to an estimated limit about 3-3J mag. fainter than the brightest nebula, we counted 73. These must be the nebulae that contribute most of the mass. Thus these 73 nebulae are equivalent to the 800 bright nebulae used in discussions of the Coma cluster, in which the number of faint nebulae has been estimated as thousands. It is this number, 73, that will be used in Section III, where the kinetic and potential energies of the Hercules cluster are obtained. II. DESCRIPTION AND OBSERVATIONS The Hercules cluster1 is an extremely interesting one, as will be seen from the plates reproduced in Figures 1-5. Figures 2-5 are reproduced from plates taken by Walter Baade with the Hale 200-inch reflector. The system is unsymmetrical, and its north- south and east-west extents are about Io and 40', respectively. The first feature that one notices is the presence of four conspicuous double systems which appear in Figures 2, 3, and 5. The members of the doubles are among the brightest nebulae in the cluster, a fact which may have some bearing on the way in which the system formed. There is at least one other double in the cluster, a relatively faint pair of spirals near the northern boundary. This is within the area covered in Figure 1 but outside the region covered by the 200-inch plates. It is more clearly visible on a plate taken with the 82-inch telescope. The second notable feature is the high proportion of spirals in comparison to elliptical and SO nebulae. Before discussing these proportions, we shall describe the results which have previously been obtained for the Virgo cluster. Hubble (1926) discussed about 400 nebulae, mostly field nebulae, and found that 74 per cent were spirals. Of the 400, about 50 belong to the Virgo cluster, and, of those, about 57 per cent are spirals. Shapley and Ames (1930) and Shapley (1950)have given percentages by types in the Virgo cluster in different apparent magnitude ranges. The percentages of spirals are as follows: lO^O-lO1^, 22 per cent; llm0-llm9, 59per cent; 49 per cent; IS^O-ld1^, 48 per cent; 14m0-14m9, 32 per cent; 15m0- 15na9, 20 per cent. In each range a small proportion—at maximum, 9 per cent—is classi- fied as irregular. From the Humason, Mayall, and Sandage (1956) catalogue of red shifts, 73 nebulae from the Virgo cluster are listed, and, of these, 27, or 37 per cent, are classified as spirals. By contrast with this it is well known that in highly condensed, centrally concentrated clusters, such as the Coma and Corona Borealis clusters, the proportion of spiral and irregular nebulae is very small (cf. Hubble, quoted by Spitzer and Baade 1951). We have not been able to find any good figures based on counts by type in clusters such as these. However, in the Coma cluster, of the 23 members for which red shifts are given by Humason et al., only 1, or about 4 per cent, has been classified as a spiral. We have classified as many of the members of the Hercules cluster as possible, using both 200-inch plates taken by Baade and plates taken at the prime focus of the 82-inch McDonald telescope. The latter plates cover a larger area than the 200-inch plates but have lower resolution. Out of the 61 galaxies classified, 69 per cent are spiral or irregular and 31 per cent elliptical or SO. This remarkably high proportion of spirals, which is apparently significantly higher than the corresponding proportion in the Virgo cluster, 1 1950 co-ordinates of center: a = ô = T 17054'. © American Astronomical Society • Provided by the NASA Astrophysics Data System 9B 62 . .130. 9ApJ. 195 ■#* Fig. 1.—Hercules cluster of nebulae. Reproduced from© American original red-sensitive Astr onomical 48-inch Society Schmidt • ProvidedolatCj Courtesy by the National NASA GeographicAstrophysics Society-Palomar Data System Observatory Sky Survey. North is at the top, east at the left Fig. 2.—Part of Hercules cluster of nebulae. Plate obtained with 200-inch Hale reflector at Palomar Observatory by Dr. Walter Baade. Plate center (1950) : = ló^B, 5 = +17054'. Orientation Éià(Asi«iciimiTig^sêr!ôi»OHtiuidaSaH;ifièT;tl?aPtliL\^tdiJcÂ\iàklfâ.NthSi\ftV4tmïplws3tii.Data System Fig. 3.—Central part of Hercules cluster of nebulae. Plate obtained with 20(Mnch Hale reflector at Palomar Observatory by Dr. Walter Baade. Plate center (1950) : a = 16h2Ii19, ô = +17054/. Orienta0(^if^i^l^AlÍPoB¡ábdcal Society • Provided by the NASA Astrophysics Data System .629B .130.
Load more

Recommended publications
  • The Large–Scale Distribution of Galaxies in the Shapley Concentration
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server The large{scale distribution of galaxies in the Shapley Concentration S. Bardelli Osservatorio Astronomico di Trieste, via Tiepolo 11, I{34131 Trieste, Italy E. Zucca, G. Zamorani Osservatorio Astronomico di Bologna, via Zamboni 33, I{40126 Bologna, Italy Abstract. We present the results of a galaxy redshift survey in the central region of the Shapley Concentration. Our total sample contains 2000 radial velocities of galaxies both in the clusters and in the inter- cluster∼ field. We reconstruct the density profile of this supercluster, cal- culate its overdensity and total mass. Moreover we detect a massive structure behind the Shapley Concentration, at 30000 km/s. ∼ 1. Introduction The Shapley Concentration stands out as the richest system of Abell clusters in the list of Zucca et al. (1993), at every density excess. In particular, at a density contrast of 2, it has 25 members (at mean velocity 14000 km/s), while at the same density∼ contrast the Great Attractor, which is∼ the largest mass 1 condensation within 80 h− Mpc, has only 6 members and the Corona Borealis and Hercules superclusters are formed by 10 and 8 clusters, respectively. While the cluster distribution in the Shapley Concentration has been well studied, little is known about the distribution of the galaxies. Determining the properties of these galaxies is very important in order to assess the physical reality and extension of the structure and to determine if galaxies and clusters trace the matter distribution in the same way.
    [Show full text]
  • Diplomarbeit Fossile Galaxiensysteme
    DIPLOMARBEIT Titel der Diplomarbeit Fossile Galaxiensysteme angestrebter akademischer Grad Magistra der Naturwissenschaften (Mag. rer. nat.) Verfasser: Eveline Glaßner Matrikel-Nummer: 9500110 Studienrichtung: Astronomie A413 Betreuer: Ao. Univ.-Prof. Dr. Werner Zeilinger Wien, Juni 2009 Zusammenfassung In meiner Arbeit wurden dynamische Endstadien von Galaxiensystemen, sog. Fos- sile Galaxiensysteme untersucht. Sie zeichnen sich durch eine massereiche zentrale Elliptische Galaxie aus, die von deutlich leuchtkraftschw¨acheren Galaxien umgeben ist. Diese Galaxien sind in einen diffusen, r¨aumlich ausgedehnten R¨ontgenhalo ein- gebettet, der auf ein ehemaliges Galaxiensystem schließen l¨asst. Insgesamt wurden 49 solcher Systeme untersucht, wobei nur 45 die Definition eines Fossilen Systems erfullen.¨ Die Auswahl setzt sich aus zwei Katalogen zusammen. Der erste Katalog stellt eine Zusammenfassung aller entdeckten Fossilen Systeme bis 2005 dar, der zweite stammt aus der Suche in der Sloan Digital Sky Survey im Jahre 2007. Als Erstes wurde die zentrale Elliptische Galaxie nach ihren photometrischen Eigen- schaften untersucht. Dies umfasst ein Fl¨achenhelligkeitsprofil, die Elliptizit¨at, den Positionswinkel und die Fourier-Koeffizienten h¨oherer Ordnung der Isophoten, die fur¨ die Bestimmung der Form (boxy bzw. disky) der Elliptischen Galaxie herange- zogen wurden. Es zeigt sich eine etwa gleichm¨aßige Aufteilung zwischen boxy und disky Elliptischen Galaxien. Der zweite Teil umfasst die spektrale Analyse der Elliptischen Galaxien. Weniger als die H¨alfte aller Elliptischen Galaxien zeigen nukleare Aktivit¨aten. Der dritte Schwerpunkt befasst sich mit der Analyse der Umgebung Fossiler Sys- teme. Bis zu einem Radius von 5 Mpc ausgehend von der zentralen Elliptischen Galaxie wurde nach weiteren Galaxien mit spektral bestimmten Rotverschiebungen gesucht. Dasselbe erfolgte auch fur¨ benachbarte Galaxiensysteme.
    [Show full text]
  • 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.
    [Show full text]
  • Arxiv:1305.7264V2 [Astro-Ph.EP] 21 Apr 2014 Spain
    Draft version September 18, 2018 Preprint typeset using LATEX style emulateapj v. 08/22/09 THE MOVING GROUP TARGETS OF THE SEEDS HIGH-CONTRAST IMAGING SURVEY OF EXOPLANETS AND DISKS: RESULTS AND OBSERVATIONS FROM THE FIRST THREE YEARS Timothy D. Brandt1, Masayuki Kuzuhara2, Michael W. McElwain3, Joshua E. Schlieder4, John P. Wisniewski5, Edwin L. Turner1,6, J. Carson7,4, T. Matsuo8, B. Biller4, M. Bonnefoy4, C. Dressing9, M. Janson1, G. R. Knapp1, A. Moro-Mart´ın10, C. Thalmann11, T. Kudo12, N. Kusakabe13, J. Hashimoto13,5, L. Abe14, W. Brandner4, T. Currie15, S. Egner12, M. Feldt4, T. Golota12, M. Goto16, C. A. Grady3,17, O. Guyon12, Y. Hayano12, M. Hayashi18, S. Hayashi12, T. Henning4, K. W. Hodapp19, M. Ishii12, M. Iye13, R. Kandori13, J. Kwon13,22, K. Mede18, S. Miyama20, J.-I. Morino13, T. Nishimura12, T.-S. Pyo12, E. Serabyn21, T. Suenaga22, H. Suto13, R. Suzuki13, M. Takami23, Y. Takahashi18, N. Takato12, H. Terada12, D. Tomono12, M. Watanabe24, T. Yamada25, H. Takami12, T. Usuda12, M. Tamura13,18 Draft version September 18, 2018 ABSTRACT We present results from the first three years of observations of moving group targets in the SEEDS high-contrast imaging survey of exoplanets and disks using the Subaru telescope. We achieve typical contrasts of ∼105 at 100 and ∼106 beyond 200 around 63 proposed members of nearby kinematic moving groups. We review each of the kinematic associations to which our targets belong, concluding that five, β Pictoris (∼20 Myr), AB Doradus (∼100 Myr), Columba (∼30 Myr), Tucana-Horogium (∼30 Myr), and TW Hydrae (∼10 Myr), are sufficiently well-defined to constrain the ages of individual targets.
    [Show full text]
  • Li Abundances in F Stars: Planets, Rotation, and Galactic Evolution,
    A&A 576, A69 (2015) Astronomy DOI: 10.1051/0004-6361/201425433 & c ESO 2015 Astrophysics Li abundances in F stars: planets, rotation, and Galactic evolution, E. Delgado Mena1,2, S. Bertrán de Lis3,4, V. Zh. Adibekyan1,2,S.G.Sousa1,2,P.Figueira1,2, A. Mortier6, J. I. González Hernández3,4,M.Tsantaki1,2,3, G. Israelian3,4, and N. C. Santos1,2,5 1 Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal e-mail: [email protected] 2 Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal 3 Instituto de Astrofísica de Canarias, C/via Lactea, s/n, 38200 La Laguna, Tenerife, Spain 4 Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain 5 Departamento de Física e Astronomía, Faculdade de Ciências, Universidade do Porto, Portugal 6 SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, UK Received 28 November 2014 / Accepted 14 December 2014 ABSTRACT Aims. We aim, on the one hand, to study the possible differences of Li abundances between planet hosts and stars without detected planets at effective temperatures hotter than the Sun, and on the other hand, to explore the Li dip and the evolution of Li at high metallicities. Methods. We present lithium abundances for 353 main sequence stars with and without planets in the Teff range 5900–7200 K. We observed 265 stars of our sample with HARPS spectrograph during different planets search programs. We observed the remaining targets with a variety of high-resolution spectrographs.
    [Show full text]
  • Download This Article in PDF Format
    A&A 583, A85 (2015) Astronomy DOI: 10.1051/0004-6361/201526795 & c ESO 2015 Astrophysics Reaching the boundary between stellar kinematic groups and very wide binaries III. Sixteen new stars and eight new wide systems in the β Pictoris moving group F. J. Alonso-Floriano1, J. A. Caballero2, M. Cortés-Contreras1,E.Solano2,3, and D. Montes1 1 Departamento de Astrofísica y Ciencias de la Atmósfera, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain e-mail: [email protected] 2 Centro de Astrobiología (CSIC-INTA), ESAC PO box 78, 28691 Villanueva de la Cañada, Madrid, Spain 3 Spanish Virtual Observatory, ESAC PO box 78, 28691 Villanueva de la Cañada, Madrid, Spain Received 19 June 2015 / Accepted 8 August 2015 ABSTRACT Aims. We look for common proper motion companions to stars of the nearby young β Pictoris moving group. Methods. First, we compiled a list of 185 β Pictoris members and candidate members from 35 representative works. Next, we used the Aladin and STILTS virtual observatory tools and the PPMXL proper motion and Washington Double Star catalogues to look for companion candidates. The resulting potential companions were subjects of a dedicated astro-photometric follow-up using public data from all-sky surveys. After discarding 67 sources by proper motion and 31 by colour-magnitude diagrams, we obtained a final list of 36 common proper motion systems. The binding energy of two of them is perhaps too small to be considered physically bound. Results. Of the 36 pairs and multiple systems, eight are new, 16 have only one stellar component previously classified as a β Pictoris member, and three have secondaries at or below the hydrogen-burning limit.
    [Show full text]
  • Guide Du Ciel Profond
    Guide du ciel profond Olivier PETIT 8 mai 2004 2 Introduction hjjdfhgf ghjfghfd fg hdfjgdf gfdhfdk dfkgfd fghfkg fdkg fhdkg fkg kfghfhk Table des mati`eres I Objets par constellation 21 1 Androm`ede (And) Andromeda 23 1.1 Messier 31 (La grande Galaxie d'Androm`ede) . 25 1.2 Messier 32 . 27 1.3 Messier 110 . 29 1.4 NGC 404 . 31 1.5 NGC 752 . 33 1.6 NGC 891 . 35 1.7 NGC 7640 . 37 1.8 NGC 7662 (La boule de neige bleue) . 39 2 La Machine pneumatique (Ant) Antlia 41 2.1 NGC 2997 . 43 3 le Verseau (Aqr) Aquarius 45 3.1 Messier 2 . 47 3.2 Messier 72 . 49 3.3 Messier 73 . 51 3.4 NGC 7009 (La n¶ebuleuse Saturne) . 53 3.5 NGC 7293 (La n¶ebuleuse de l'h¶elice) . 56 3.6 NGC 7492 . 58 3.7 NGC 7606 . 60 3.8 Cederblad 211 (N¶ebuleuse de R Aquarii) . 62 4 l'Aigle (Aql) Aquila 63 4.1 NGC 6709 . 65 4.2 NGC 6741 . 67 4.3 NGC 6751 (La n¶ebuleuse de l’œil flou) . 69 4.4 NGC 6760 . 71 4.5 NGC 6781 (Le nid de l'Aigle ) . 73 TABLE DES MATIERES` 5 4.6 NGC 6790 . 75 4.7 NGC 6804 . 77 4.8 Barnard 142-143 (La tani`ere noire) . 79 5 le B¶elier (Ari) Aries 81 5.1 NGC 772 . 83 6 le Cocher (Aur) Auriga 85 6.1 Messier 36 . 87 6.2 Messier 37 . 89 6.3 Messier 38 .
    [Show full text]
  • NEWSLETTER August 2015
    NEWSLETTER August 2015 New Horizons at Pluto Credit NASA This space is reserved for promoting member's businesses. You can place an advert here for a donation to the group. Issue 11 August 2015 Page 1 Contents Cover 1 Contents 2 About the cover picture New Horizons 3-7 Thanet Astronomy Group Contact Details 8 Member's Meeting Dates and Times 9 Advertisement (West Bay Cafe) 10 What we did last month 11 Junior Members Page 12 Advertisement (Renaissance Glass) 13 Book Review 14 What's in the sky this month 15-17 Member's Page 18-19 Did You Know ? 20 Junior Astronomers Club (JAC & Gill) 21 Executive Committee Messages 22 Adult Word Search 23 Junior Word Search 24 Member's For Sale and Wanted 25 Issue 11 August 2015 Page 2 About the Cover Picture NEW HORIZONS New Horizons at Pluto Credit NASA New Horizons The Mission The New Horizons mission is the first mission to Pluto and the Kuiper Belt This mission has sent a space craft to the outer reaches of our Solar System to look at the dwarf planet Pluto, and beyond into the Kuiper Belt. The Kuiper Belt is the region of our Solar System beyond the orbit of the planet Neptune, about 30 Astronomical Units (AU) from the Sun and out to about 50 AU. This region contains the minor planet Pluto and its moons Charon, Hydra, Nix and Styx along with many comets, asteroids and many other small objects mostly made of ice. The Kuiper Belt - Credit: NASA Issue 11 August 2015 Page 3 About the Cover Picture NEW HORIZONS An AU or Astronomical Unit is equal to the distance between the Sun and the Earth about 93,000,000 miles or 150,000,000 km.
    [Show full text]
  • Arxiv:1603.08040V2 [Astro-Ph.SR] 16 Apr 2016 Visible to the Satellite
    Submitted to The Astrophysical Journal Preprint typeset using LATEX style emulateapj v. 5/2/11 THE ALLWISE MOTION SURVEY, PART 2 J. Davy Kirkpatrick1, Kendra Kellogg1,2, Adam C. Schneider3, Sergio Fajardo-Acosta1, Michael C. Cushing3, Jennifer Greco3, Gregory N. Mace4, Christopher R. Gelino1, Edward L. Wright5, Peter R. M. Eisenhardt6, Daniel Stern6, Jacqueline K. Faherty7, Scott S. Sheppard7, George B. Lansbury8, Sarah E. Logsdon5, Emily C. Martin5, Ian S. McLean5, Steven D. Schurr1, Roc M. Cutri1, Tim Conrow1 Submitted to The Astrophysical Journal ABSTRACT We use the AllWISE Data Release to continue our search for WISE-detected motions. In this paper, we publish another 27,846 motion objects, bringing the total number to 48,000 when objects found during our original AllWISE motion survey are included. We use this list, along with the lists of confirmed WISE-based motion objects from the recent papers by Luhman and by Schneider et al. and candidate motion objects from the recent paper by Gagn´eet al. to search for widely separated, common-proper-motion systems. We identify 1,039 such candidate systems. All 48,000 objects are further analyzed using color-color and color-mag plots to provide possible characterizations prior to spectroscopic follow-up. We present spectra of 172 of these, supplemented with new spectra of 23 comparison objects from the literature, and provide classifications and physical interpretations of interesting sources. Highlights include: (1) the identification of three G/K dwarfs that can be used as standard candles
    [Show full text]
  • Divinus Lux Observatory Bulletin: Report # 27
    Vol. 9 No. 1 January 1, 2013 Journal of Double Star Observations Page 10 Divinus Lux Observatory Bulletin: Report # 27 Dave Arnold Program Manager for Double Star Research 2728 North Fox Run Drive Flagstaff, AZ 86004 Email: [email protected] Abstract: This report contains theta/rho measurements from 120 different double star systems. The time period spans from 2012.189 to 2012.443. Measurements were obtained using a 20-cm Schmidt-Cassegrain telescope and an illuminated reticle micrometer. This report represents a portion of the work that is currently being conducted in double star astronomy at Divinus Lux Observatory in Flagstaff, Arizona. This article contains a listing of double star the theta value. Perhaps AC warrants further scru- measurements that are part of a series, which have tiny by others in order to determine, more accu- been continuously reported at Divinus Lux Observa- rately, what these parameters actually are. tory, since the spring of 2001. The selected double Some other apparent discrepancies in the star systems, which appear in the table below, have catalog involve the STF 2319 (18277+1918) star sys- been taken exclusively from the 2006.5 version of the tem. To begin with, the measurements for the AC Washington Double Star Catalog, with published components appear to more nearly match the pa- measurements that are no more recent than ten rameters for BC, while the BC measurements appear years ago. There are also some noteworthy items to match the AC parameters. In addition, the theta that are discussed, which pertain to a few of the measurements for AD appear to reflect a quadrant measured systems.
    [Show full text]
  • Radio Investigations of Clusters of Galaxies
    • • RADIO INVESTIGATIONS OF CLUSTERS OF GALAXIES a study of radio luminosity functions, wide-angle head-tailed radio galaxies and cluster radio haloes with the Westerbork Synthesis Radio Telescope proefschrift ter verkrijging van degraad van Doctor in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit te Leiden, op gezag van de Rector Magnificus Or. D.J. Kuenen, hoogleraar in de Faculteit der Wiskunde en Natuurwetenschappen, volgens besluit van het College van Dekanen te verdedigen op woensdag 20 december 1978 teklokke 15.15 uur door Edwin Auguste Valentijn geboren te Voorburg in 1952 Sterrewacht Leiden 1978 elve/labor vincit - Leiden Promotor: Prof. Dr. H. van der Laan aan Josephine aan mijn ouders Cover: Some radio contours (1415 MHz) of the extended radio galaxies NGC6034, NGC6061 and 1B00+1SW2 superimposed to a smoothed galaxy distribution (number of galaxies per unit area, taken from Shane) of the Hercules Superoluster. The 90 % confidence error boxes of the Ariel VandUHURU observations of the X-ray source A1600+16 are also included. In the region of overlap of these two error boxes the position of a oD galaxy is indicated. The combined picture suggests inter-galactic material pervading the whole superaluster. CONTENTS CHAPTER 1 GENERAL INTRODUCTION AND SUMMARY 9 PART 1 OBSERVATIONS OF THE COI1A CLUSTER AT 610 MHZ 15 CHAPTER 2 COMA CLUSTER GALAXIES 17 Observation of the Coma Cluster at 610 MHz (Paper III, with W.J. Jaffe and G.C. Perola) I Introduction 17 II Observations 18 III Data Reduction 18 IV Radio Source Parameters 19 V Optical Data 20 VI The Radio Luminosity Function of the Coma Cluster Galaxies 21 a) LF of the (E+SO) Galaxies 23 b) LF of the (S+I) Galaxies 25 c) Radial Dependence of the LF 26 VII Other Properties of the Detected Cluster Galaxies 26 a) Spectral Indexes b) Emission Lines VIII The Central Radio Sources 27 a) 5C4.85 = NGC4874 27 b) 5C4.8I - NGC4869 28 c) Coma C 29 CHAPTER 3 RADIO SOURCES IN COMA NOT IDENTIFIED WITH CLUSTER GALAXIES 31 Radio Data and Identifications (Paper IV, with G.C.
    [Show full text]
  • Pivotal Role of Spin in Celestial Body Motion Mechanics: Prelude to a Spinning Universe
    Journal of High Energy Physics, Gravitation and Cosmology, 2021, 7, 98-122 https://www.scirp.org/journal/jhepgc ISSN Online: 2380-4335 ISSN Print: 2380-4327 Pivotal Role of Spin in Celestial Body Motion Mechanics: Prelude to a Spinning Universe Puthalath Koroth Raghuprasad Independent Researcher, Odessa, TX, USA How to cite this paper: Raghuprasad, P.K. Abstract (2021) Pivotal Role of Spin in Celestial Body Motion Mechanics: Prelude to a This is the final article in our series dealing with the interplay of spin and Spinning Universe. Journal of High Energy gravity that leads to the generation, and continuation of celestial body mo- Physics, Gravitation and Cosmology, 7, tions in the universe. In our prior studies we focused on such interactions in 98-122. https://doi.org/10.4236/jhepgc.2021.71005 the elementary particles, and in the celestial bodies in the solar system. Fore- most among the findings was that, along with gravity, matter at all levels ex- Received: March 23, 2020 hibits axial spin. We further noted that all freestanding bodies outside our Accepted: December 19, 2020 solar system, including the largest such units, the stars and galaxies also spin Published: December 22, 2020 on their axes. Also, the axial rotation speed of planets in our solar system has Copyright © 2021 by author(s) and a linear positive relationship to their masses, thus hinting at its fundamental Scientific Research Publishing Inc. and autonomous nature. We have reported that this relationship between the This work is licensed under the Creative size of the body and its axial rotation speed extends to the stars and even the Commons Attribution International License (CC BY 4.0).
    [Show full text]