Andromeda 2-2021 Zeitschrift Der Sternfreunde Münster
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Arxiv:1910.11169V1 [Astro-Ph.EP] 24 Oct 2019 Metchev Et Al.(2004) Due to the Detection of a Strong Mid- Tinuum and at HCO+ and CO Gas Emission Lines
Astronomy & Astrophysics manuscript no. PDS70_v2 c ESO 2019 October 25, 2019 VLT/SPHERE exploration of the young multiplanetary system PDS70? D. Mesa1, M. Keppler2, F. Cantalloube2, L. Rodet3, B. Charnay4, R. Gratton1, M. Langlois5; 6, A. Boccaletti4, M. Bonnefoy3, A. Vigan6, O. Flasseur7, J. Bae8, M. Benisty3; 9, G. Chauvin3; 9, J. de Boer10, S. Desidera1, T. Henning2, A.-M. Lagrange3, M. Meyer11, J. Milli12, A. Müller2, B. Pairet13, A. Zurlo14; 15; 6, S. Antoniucci16, J.-L. Baudino17, S. Brown Sevilla2, E. Cascone18, A. Cheetham19, R.U. Claudi1, P. Delorme3, V. D’Orazi1, M. Feldt2, J. Hagelberg19, M. Janson20, Q. Kral4, E. Lagadec21, C. Lazzoni1, R. Ligi22, A.-L. Maire2; 23, P. Martinez21, F. Menard3, N. Meunier3, C. Perrot4; 24; 25, S. Petrus3, C. Pinte26; 3, E.L. Rickman19, S. Rochat3, D. Rouan4, M. Samland2; 20, J.-F. Sauvage27; 6, T. Schmidt4; 28, S. Udry19, L. Weber19, F. Wildi19 (Affiliations can be found after the references) Received / accepted ABSTRACT Context. PDS 70 is a young (5.4 Myr), nearby (∼113 pc) star hosting a known transition disk with a large gap. Recent observations with SPHERE and NACO in the near-infrared (NIR) allowed us to detect a planetary mass companion, PDS 70 b, within the disk cavity. Moreover, observations in Hα with MagAO and MUSE revealed emission associated to PDS 70 b and to another new companion candidate, PDS 70 c, at a larger separation from the star. PDS 70 is the only multiple planetary system at its formation stage detected so far through direct imaging. Aims. Our aim is to confirm the discovery of the second planet PDS 70 c using SPHERE at VLT, to further characterize its physical properties, and search for additional point sources in this young planetary system. -
The Nearest Stars: a Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific
www.astrosociety.org/uitc No. 5 - Spring 1986 © 1986, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. The Nearest Stars: A Guided Tour by Sherwood Harrington, Astronomical Society of the Pacific A tour through our stellar neighborhood As evening twilight fades during April and early May, a brilliant, blue-white star can be seen low in the sky toward the southwest. That star is called Sirius, and it is the brightest star in Earth's nighttime sky. Sirius looks so bright in part because it is a relatively powerful light producer; if our Sun were suddenly replaced by Sirius, our daylight on Earth would be more than 20 times as bright as it is now! But the other reason Sirius is so brilliant in our nighttime sky is that it is so close; Sirius is the nearest neighbor star to the Sun that can be seen with the unaided eye from the Northern Hemisphere. "Close'' in the interstellar realm, though, is a very relative term. If you were to model the Sun as a basketball, then our planet Earth would be about the size of an apple seed 30 yards away from it — and even the nearest other star (alpha Centauri, visible from the Southern Hemisphere) would be 6,000 miles away. Distances among the stars are so large that it is helpful to express them using the light-year — the distance light travels in one year — as a measuring unit. In this way of expressing distances, alpha Centauri is about four light-years away, and Sirius is about eight and a half light- years distant. -
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. -
The Radio Continuum View of Centaurus Acentaurus A
TheThe radioradio continuumcontinuum viewview ofof CentaurusCentaurus AA Ron Ekers CSIRO The Many Faces of Centaurus A Sydney, 29 June 2009 Ilana's composite Morganti et al. 1999 9° 10' Burns et al. xx image courtesy Norbert Junkes (MPIfR) WhyWhy CentaurusCentaurus AA isis specialspecial ■ the first extragalactic radio source ■ the brightest source in the Southern Hemisphere ■ the second double lobed source discovered ± after Cygnus A ■ the closest Radio Galaxy ■ the closest AGN ■ the closest SMBH ± VLBI resolution 0.01pc, 100 Rs ■ A spectacular galaxy EvolutionEvolution ofof thethe ModelsModels ■ Radio sources ± Static magnetic field 1960 ± Evolutionary sequence 1970 ± Continuous injection ± Continuous reacceleration ■ Energy source ± Galaxy collisions 1950's ± Nuclear accretions 1960- ± Accretion triggered by collisions 1980- CentaurusCentaurus AA thethe closestclosest AGNAGN ■ Distance 3.4Mpc ■ Next closest comparable AGN M87 17Mpc ! ■ Average distance to a L=1024 W Hz-1 radio galaxies ± 10Mpc ± So we are lucky (or influenced!) ■ Much easier to study at all wavelengths ■ Subtends a large angular size ± Good linear resolution ± Background probes SomeSome RadioRadio GalaxiesGalaxies Name Size Log Log (kpc) Luminosity Energy (ergs sec-1) (ergs) Centaurus A 470 41.7 59.9 Cygnus A 200 45.2 60.6 M87 80 42.0 58.6 M82 1 39.5 55.2 PolarizationPolarization inin CentaurusCentaurus AA Bracewell 1962 ■ April 1962 ■ Parkes 64m just completed ■ Discovered by Bracewell ± Published Cooper and Price ± Visitors Log ± Not a National Facilities yet! ■ Connie -
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 . -
TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-Like Star HD 108236
Swarthmore College Works Physics & Astronomy Faculty Works Physics & Astronomy 2-1-2021 TESS Discovery Of A Super-Earth And Three Sub-Neptunes Hosted By The Bright, Sun-Like Star HD 108236 T. Daylan K. Pinglé J. Wright M. N. Günther K. G. Stassun Follow this and additional works at: https://works.swarthmore.edu/fac-physics See P nextart of page the forAstr additionalophysics andauthors Astr onomy Commons Let us know how access to these works benefits ouy Recommended Citation T. Daylan, K. Pinglé, J. Wright, M. N. Günther, K. G. Stassun, S. R. Kane, A. Vanderburg, D. Jontof-Hutter, J. E. Rodriguez, A. Shporer, C. X. Huang, T. Mikal-Evans, M. Badenas-Agusti, K. A. Collins, B. V. Rackham, S. N. Quinn, R. Cloutier, K. I. Collins, P. Guerra, Eric L.N. Jensen, J. F. Kielkopf, B. Massey, R. P. Schwarz, D. Charbonneau, J. J. Lissauer, J. M. Irwin, Ö Baştürk, B. Fulton, A. Soubkiou, B. Zouhair, S. B. Howell, C. Ziegler, C. Briceño, N. Law, A. W. Mann, N. Scott, E. Furlan, D. R. Ciardi, R. Matson, C. Hellier, D. R. Anderson, R. P. Butler, J. D. Crane, J. K. Teske, S. A. Shectman, M. H. Kristiansen, I. A. Terentev, H. M. Schwengeler, G. R. Ricker, R. Vanderspek, S. Seager, J. N. Winn, J. M. Jenkins, Z. K. Berta-Thompson, L. G. Bouma, W. Fong, G. Furesz, C. E. Henze, E. H. Morgan, E. Quintana, E. B. Ting, and J. D. Twicken. (2021). "TESS Discovery Of A Super-Earth And Three Sub-Neptunes Hosted By The Bright, Sun-Like Star HD 108236". -
Gli Ammassi Di Galassie
Universo in Fiore 2017 CORSO BASE I GIGANTI DEL COSMO: GLI AMMASSI DI GALASSIE Sabrina De Grandi [email protected] Organizzazione spaziale delle galassie Ammassi Gruppi Galassie 100 mila a.l. ~30 kpc 3 milioni a.l. ~ 103 kpc 20 milioni a.l. ~ 7x103 kpc I primi cataloghi di ammassi Fino agli anni ’80: ispezione visuale di lastre fotografiche alla ricerca di sovradensita` di galassie. Es. di lastre fotografiche: • PSS: National Geographic Society-Palomar Observatory Sky Survey (Telescopio 5m Hale, Mt. Wilson US) • UKST: Schmidt telescope IIIa-J plates (Telescopio 1.2m, UK-Australia),… I cataloghi di Abell (1958) e Zwicky (1961-1968) Il catalogo piu` usato: Abell (1958) Emisfero Nord (2712) e A.C.O. (1989) Emisfero Sud (1364). 1958: Abell ispeziono` di 104 deg2 di lastre PSS (Luna ~0.25 deg2) Criteri principali: • almeno 30 galassie • compatto (0.02<z<0.2) • piano galattico escluso Dagli anni ’90: • algoritmi automatici di identificazione al posto dell’occhio umano. • Non più lastre fotografiche, ma immagini digitali (CCD) • SDSS (Sloan Digital Sky Survey), iniziata nel 2000 e tutt’ora in atto (35% del cielo osservato, 500 milioni di oggetti, catalogo di ammassi • Accesso libero ai dati (nel Telescopio dedicato ad 2015: 13o Data Release) Apache Point 2.5m (US) Immagine SDSS dell’ammasso A2142 MACS J1206.2-0847 DIAMETRO tipico di un ammasso di galassie ~ 20 milioni anni luce ~ 7 Mpc SPICA (훼 costellazione della Vergine) MACS J1206.2-0847 DIAMETRO tipico di un ammasso di galassie ~ 20 milioni anni luce ~ 7 Mpc ma… DISTANZA di MACS J1206 ~ 4.5 miliardi di anni luce ~ 1500 Mpc Dove si trova la Via Lattea in questa struttura universale? ovvero Noi ci troviamo in un Ammasso di galassie? Il Gruppo Locale 100.000 a.l. -
The Sky This Week
The sky this week April 20 to April 26, 2020 By Joe Grida, Technical Informaon Officer, ASSA ([email protected]) elcome to the fourth edion of The Sky this Week. It is designed to keep you looking up during these rather uncertain mes. We can’t get together for Members’ Viewing Nights, so I thought I’d write this W to give you some ideas of observing targets that you can chase on any clear night this coming week. As I said in my recent Starwatch* column in The Adverser newspaper: “Even with the restricons in place, stargazing is something that you can do easily on your own. It helps to relieve stress and will keep your sense of perspecve. It’s prey hard to walk away from a night under the stars without a jusfiable sense of awe. And also without sensing a real, albeit tenuous, connecon with the cosmos at large”. * Published on the last Friday of each month Naked eye star walk Over in the eastern late evening sky, Scorpius, the Scorpion (one of the few constellaons in our sky that actually resembles what it is supposed to represent) is difficult to miss. He will keep us company over the coming chilly winter months. Its brightest star, Antares, is a huge star of gargantuan proporons. If we replaced our Sun with it, then all the planets from Mercury through to Jupiter would all find themselves engulfed within it! Just below the tail of Scorpius, you can find the star clusters designated M6 and M7. Take the trouble to observe these with binoculars. -
A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3]. -
An Early Detection of Blue Luminescence by Neutral Pahs in the Direction of the Yellow Hypergiant HR 5171A?
A&A 583, A98 (2015) Astronomy DOI: 10.1051/0004-6361/201526392 & c ESO 2015 Astrophysics An early detection of blue luminescence by neutral PAHs in the direction of the yellow hypergiant HR 5171A? A. M. van Genderen1, H. Nieuwenhuijzen2, and A. Lobel3 1 Leiden Observatory, Leiden University, Postbus 9513, 2300RA Leiden, The Netherlands e-mail: [email protected] 2 SRON Laboratory for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands 3 Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium Received 23 April 2015 / Accepted 23 August 2015 ABSTRACT Aims. We re-examined photometry (VBLUW, UBV, uvby) of the yellow hypergiant HR 5171A made a few decades ago. In that study no proper explanation could be given for the enigmatic brightness excesses in the L band (VBLUW system, λeff = 3838 Å). In the present paper, we suggest that this might have been caused by blue luminescence (BL), an emission feature of neutral polycyclic aromatic hydrocarbon molecules (PAHs), discovered in 2004. It is a fact that the highest emission peaks of the BL lie in the L band. Our goals were to investigate other possible causes, and to derive the fluxes of the emission. Methods. We used two-colour diagrams based on atmosphere models, spectral energy distributions, and different extinctions and extinction laws, depending on the location of the supposed BL source: either in Gum48d on the background or in the envelope of HR 5171A. Results. False L–excess sources, such as a hot companion, a nearby star, or some instrumental effect, could be excluded. Also, emission features from a hot chromosphere are not plausible. -
The Giant That Turned out to Be a Dwarf 7 March 2007
The giant that turned out to be a dwarf 7 March 2007 New data obtained on the apparent celestial have very different redshifts, with NGC 5011C couple, NGC 5011 B and C, taken with the 3.6-m moving away from us five times slower than its ESO telescope, reveal that the two galaxies are companion on the sky. "This indicates they are at not at the same distance, as was believed for the different distances and not at all associated", says past 23 years. The observations show that NGC Jerjen. "Clearly, NGC 5011C belongs to the close 5011C is not a giant but a dwarf galaxy, an group of galaxies centred around Centaurus A, overlooked member of a group of galaxies in the while NGC 5011B is part of the much farther vicinity of the Milky Way. Centaurus cluster." The galaxy NGC 5011C is located towards the The astronomers also established that the two Centaurus constellation, in the direction of the galaxies have very different intrinsic properties. Centaurus A group of galaxies and the Centaurus NGC 5011B contains for example more heavy cluster of galaxies. The former is about 13 million chemical elements than NGC 5011C, and the latter light-years from our Milky Way, while the latter is seems to contain only about 10 million times the about 12 times farther away. mass of the Sun in stars and is therefore a true dwarf galaxy. For comparison, our Milky Way The appearance of NGC 5011C, with its low contains thousands of times more stars. density of stars and absence of distinctive features, would normally lead astronomers to "Our new observations with the 3.6-m ESO classify it as a nearby dwarf elliptical galaxy. -
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.