DOCSLIB.ORG

Glorious Colours of the Rho Ophiuchi Cloud Complex the Best of Monochrome

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Glorious Colours of the Rho Ophiuchi Cloud Complex the Best of Monochrome The Journal of The Royal Astronomical Society of Canada PROMOTING ASTRONOMY IN CANADA December/décembre 2016 Volume/volume 110 Le Journal de la Société royale d’astronomie du Canada Number/numéro 6 [781] Inside this issue: Percival Lowell’s Last Year Newbie No More Glorious Colours of the Rho Ophiuchi Cloud Complex The Best of Monochrome. Drawings, images in black and white, or narrow-band photography. Ron Brecher took this image of Sh2-72, an emission nebula in Aquila from SkyShed in Guelph, Ontario, combining the red, green, and blue colour channels with data collected through a deep red H-alpha filter. Brecher used an SBIG STL-11000M camera, Baader αH , R, G, and B filters, and a10α ƒ/6.8 ASA astrograph on a Paramount MX for a total of 15 hours. December/décembre 2016 | Vol. 110, No. 6 | Whole Number 781 contents / table des matières Feature Articles / Articles de fond 257 Dish on the Cosmos: Connecting the Cycle of Star Formation 224 Percival Lowell’s Last Year by Erik Rosolowsky by William Sheehan 259 John Percy’s Universe: The Little Campus that 236 First experience at the General Assembly Grew by Stan Taylor by John R. Percy Columns / Rubriques 261 Second light: Time domain X-ray astronomy by Leslie J. Sage 237 CFHT Chronicles: Destination: Proxima Centauri, Part I: Going Interstellar: Time, Departments / Départements Distance, Velocity, & Acceleration by Mary Beth Laychak 218 President’s Corner by Craig Levine 240 Pen and Pixel: 219 News Notes / En manchettes Elephant Trunk / Dumbbell Nebula / Soul Compiled by Jay Anderson Nebula / NGC 7129 By Andre Paquette / Blair MacDonald / Dan Meek / Drew 260 Awards Deadline Patterson by James Edgar 242 Astronomical Art & Artifact: Time on Display in 262 Astrocryptic and October Answers Civic Landscapes: Quebec City by Curt Nason by Randall Rosenfeld 262 It’s Not All Sirius 247 Imager’s Corner: Resolution, Image Sharpness, by Ted Dunphy and Interpolation by Blair MacDonald 263 Index to Volume 110 252 Binary Universe: Let Them Trail by Blake Nancarrow 255 Skyward: My first mentor and a streak of light by David Levy Accomplished astrophotographer Lynn Hilborn imaged the heart of the Rho Ophiuchi cloud complex from his Whistlestop Observatory in Grafton, Ontario. Hilborn used a TS71 telescope at ƒ/5, Moravian G2-8300 camera, and Baader filters on a Tak NJP Temma2 mount. December / décembre 2016 JRASC | Promoting Astronomy in Canada 217 The Journal is a bi-monthly publication of The Royal President’s Corner Astronomical Society of Canada and is devoted to the advancement of astronomy and allied sciences. by Craig Levine, London Centre It contains articles on Canadian astronomers and current activities of the RASC and its ([email protected]) Centres, research and review papers by professional and amateur astronomers, and articles of a historical, biographical, or educational nature of general interest to the astronomical community. All contributions are welcome, but the editors reserve the right to edit material prior to publication. Research papers are reviewed prior to publication, and professional As the deadline for this column rapidly astronomers with institutional affiliations are asked to pay publication charges of $100 per approached and then suddenly leapt out at page. Such charges are waived for RASC members who do not have access to professional me like my smallest cat making a valiant funds as well as for solicited articles. Manuscripts and other submitted material may be in English or French, and should be sent to the Editor-in-Chief. attempt to get our eldest border collie to play with him, I began thinking about the RASC, how I perceive it, and how it Editor-in-Chief Contributing Editors is perceived by the many constituencies within our venerable Nicole Mortillaro Jay Anderson (News Notes) Email: [email protected] Ted Dunphy (It’s Not All Sirius) society and beyond. The more I thought about it, the more Web site: www.rasc.ca Mary Beth Laychak (CFHT Chronicles) it became clear how multifaceted the answer to the question Telephone: 416-924-7973 David Levy (Skyward) Fax: 416-924-2911 Blair MacDonald (Imager’s Corner) “What is the RASC?” and, depending on the facet that’s Blake Nancarrow (Binary Universe) Associate Editor, Research being examined, it can be a very good thing, or it can present Curt Nason (Astrocryptic) Douglas Hube John R. Percy (John Percy’s Universe) challenges and accompanying opportunities. Email: [email protected] Randall Rosenfeld (Art & Artifact) Associate Editor, General Eric Rosolowsky (Dish on the Cosmos) What we are can be broken down into three core functions: a Michael Attas Leslie J. Sage (Second Light) membership organization, a charitable entity, and a publishing Email: [email protected] Rick Saunders (Maker’s Minute) Assistant Editors David Turner (Reviews) concern. I want to focus on the membership organization Michael Allen Proofreaders component for this column. Martin Beech Michele Arenburg Dave Chapman Ossama El Badawy Much of our activities happen at the local level in our Centres, Ralph Chou Margaret Brons Ralph Croning Angelika Hackett and this is where the majority of our members are focused. Dave Garner Kim Leitch For them, the RASC is their club for all things astronomy, Patrick Kelly Design/Production for attending public talks, engaging in outreach if they are so Editorial Assistant Michael Gatto, Grant Tomchuk Michele Arenburg Email: [email protected], inclined, observing, and for the fellowship of a shared passion. Email: [email protected] [email protected] And rightly so. For many of our members, myself included, our Production Manager Advertising local Centres were the catalyst that ignited our life-long love James Edgar Julia Neeser Email: [email protected] Email: [email protected] of astronomy and the RASC. Printing Cansel A smaller subset of our membership is involved with the www.cansel.ca RASC’s national activities on Council, committees, the Board, as writers and editors, and as speakers willing to travel to one His Excellency the Right Honourable David Johnston, C.C., C.M.M., C.O.M., C.D., of our many Centres to share their knowledge and experi- Governor General of Canada, is the Viceregal Patron of the RASC. ences. They, and many of our members in general, feel no small The Journal of The Royal Astronomical Society of Canada is published at an annual measure of pride in being part of a truly national organization subscription rate of $93.45 (including tax) by The Royal Astronomical Society of Canada. Membership, which includes the publications (for personal use), is open to anyone interested that is held in high regard for its venerable and long history, in astronomy. Applications for subscriptions to the Journal or membership in the RASC and and for the consistent quality of its publications. That our information on how to acquire back issues of the Journal can be obtained from: Observer’s Handbook can be found in a great many professional The Royal Astronomical Society of Canada observatories is testament to the dedication and passion of our 203 – 4920 Dundas St W Toronto ON M9A 1B7, Canada long line of editors and contributors. Our local, national, and Email: [email protected] international reputation’s foundation, our gravitas if you will, Web site: www.rasc.ca is built on our members who donate so freely of their time Telephone: 416-924-7973 either at their Centres and are the face of public astronomy in Fax: 416-924-2911 Canada, or who have a passion for our being part of something Canadian Publications Mail Registration No. 09818 pan-Canadian in support of our members in all regions. And Canada Post: Send address changes to 203 – 4920 Dundas St W, Toronto ON M9A 1B7 the Society as a whole. Canada Post Publication Agreement No. 40069313 We acknowledge the financial support of the Government of Canada through the Canada Periodical Fund (CPF) for our publishing activities. © 2016 The Royal Astronomical Society of Canada. All rights reserved. ISSN 0035-872X Cert no. SW-COC-005174 218 JRASC | Promoting Astronomy in Canada December / décembre 2016 A challenge the RASC faces in regard to growth and our from the diverse communities across our county and within demographics may lie in perception. We have the word “Royal” the regions our Centres draw their members from. This is an in our name (and I’m proud of it), and our raison d’être has opportunity for all levels of the organization to grow, spread the weight of science behind it. I’m musing here, but I think the joy of astronomy further, and to bring fresh ideas and that combination may intimidate some. I think back to the initiatives into our tent. time when I discovered the RASC, and my image of the RASC based on those two factors was vastly different from Reaching out to new members and incorporating fresh the wonderful reality that has played a large role in my adult perspectives will require new ideas and methods of outreach life. Our demographics skew disproportionately to male, from all levels of the RASC. As we craft our strategic plan Caucasian, and middle-aged and older. That tells me that to take us into the future, I’m looking forward to hearing at the national and local levels, we have to work harder and and discussing the innovative ideas our members will bring V smarter at reaching out to Canadian women, youth, and adults forward. News Notes / En Manchettes was able to send measurements and images for only 48 hours before its battery ran down. Rosetta itself operated nearly Compiled by Jay Anderson, FRASC flawlessly, observing Churyumov-Gerasimenko from beyond the orbit of Mars to past perihelion and onward. A trooper to the end, Rosetta’s last image was taken from only 20 m above Rosetta settles into retirement the comet’s surface.
Load more

Recommended publications
  • Filter Performance Comparisons for Some Common Nebulae
    Filter Performance Comparisons For Some Common Nebulae By Dave Knisely Light Pollution and various “nebula” filters have been around since the late 1970’s, and amateurs have been using them ever since to bring out detail (and even some objects) which were difficult to impossible to see before in modest apertures. When I started using them in the early 1980’s, specific information about which filter might work on a given object (or even whether certain filters were useful at all) was often hard to come by. Even those accounts that were available often had incomplete or inaccurate information. Getting some observational experience with the Lumicon line of filters helped, but there were still some unanswered questions. I wondered how the various filters would rank on- average against each other for a large number of objects, and whether there was a “best overall” filter. In particular, I also wondered if the much-maligned H-Beta filter was useful on more objects than the two or three targets most often mentioned in publications. In the summer of 1999, I decided to begin some more comprehensive observations to try and answer these questions and determine how to best use these filters overall. I formulated a basic survey covering a moderate number of emission and planetary nebulae to obtain some statistics on filter performance to try to address the following questions: 1. How do the various filter types compare as to what (on average) they show on a given nebula? 2. Is there one overall “best” nebula filter which will work on the largest number of objects? 3.
    [Show full text]
  • Explore the Universe Observing Certificate Second Edition
    RASC Observing Committee Explore the Universe Observing Certificate Second Edition Explore the Universe Observing Certificate Welcome to the Explore the Universe Observing Certificate Program. This program is designed to provide the observer with a well-rounded introduction to the night sky visible from North America. Using this observing program is an excellent way to gain knowledge and experience in astronomy. Experienced observers find that a planned observing session results in a more satisfying and interesting experience. This program will help introduce you to amateur astronomy and prepare you for other more challenging certificate programs such as the Messier and Finest NGC. The program covers the full range of astronomical objects. Here is a summary: Observing Objective Requirement Available Constellations and Bright Stars 12 24 The Moon 16 32 Solar System 5 10 Deep Sky Objects 12 24 Double Stars 10 20 Total 55 110 In each category a choice of objects is provided so that you can begin the certificate at any time of the year. In order to receive your certificate you need to observe a total of 55 of the 110 objects available. Here is a summary of some of the abbreviations used in this program Instrument V – Visual (unaided eye) B – Binocular T – Telescope V/B - Visual/Binocular B/T - Binocular/Telescope Season Season when the object can be best seen in the evening sky between dusk. and midnight. Objects may also be seen in other seasons. Description Brief description of the target object, its common name and other details. Cons Constellation where object can be found (if applicable) BOG Ref Refers to corresponding references in the RASC’s The Beginner’s Observing Guide highlighting this object.
    [Show full text]
  • 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.
    [Show full text]
  • Winter Constellations
    Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great ​ ​ hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar ​ ​ ​ nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. ​ ​ 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming ​ “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the ​ Orion Nebula.
    [Show full text]
  • 1. Introduction
    THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 122:109È150, 1999 May ( 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. GALAXY STRUCTURAL PARAMETERS: STAR FORMATION RATE AND EVOLUTION WITH REDSHIFT M. TAKAMIYA1,2 Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637; and Gemini 8 m Telescopes Project, 670 North Aohoku Place, Hilo, HI 96720 Received 1998 August 4; accepted 1998 December 21 ABSTRACT The evolution of the structure of galaxies as a function of redshift is investigated using two param- eters: the metric radius of the galaxy(Rg) and the power at high spatial frequencies in the disk of the galaxy (s). A direct comparison is made between nearby (z D 0) and distant(0.2 [ z [ 1) galaxies by following a Ðxed range in rest frame wavelengths. The data of the nearby galaxies comprise 136 broad- band images at D4500A observed with the 0.9 m telescope at Kitt Peak National Observatory (23 galaxies) and selected from the catalog of digital images of Frei et al. (113 galaxies). The high-redshift sample comprises 94 galaxies selected from the Hubble Deep Field (HDF) observations with the Hubble Space Telescope using the Wide Field Planetary Camera 2 in four broad bands that range between D3000 and D9000A (Williams et al.). The radius is measured from the intensity proÐle of the galaxy using the formulation of Petrosian, and it is argued to be a metric radius that should not depend very strongly on the angular resolution and limiting surface brightness level of the imaging data. It is found that the metric radii of nearby and distant galaxies are comparable to each other.
    [Show full text]
  • Successful Observing Sessions HOWL-EEN FUN Kepler’S Supernova Remnant Harvard’S Plate Project and Women Computers
    Published by the Astronomical League Vol. 69, No. 4 September 2017 Successful Observing Sessions HOWL-EEN FUN Kepler’s Supernova Remnant Harvard’s Plate Project and Women Computers T HE ASTRONOMICAL LEAGUE 1 he 1,396th entry in John the way to HR 8281, is the Dreyer’s Index Catalogue of Elephant’s Trunk Nebula. The T Nebulae and Clusters of left (east) edge of the trunk Stars is associated with a DEEP-SKY OBJECTS contains bright, hot, young galactic star cluster contained stars, emission nebulae, within a large region of faint reflection nebulae, and dark nebulosity, and a smaller region THE ELEPHANT’S TRUNK NEBULA nebulae worth exploring with an within it called the Elephant’s 8-inch or larger telescope. Trunk Nebula. In general, this By Dr. James R. Dire, Kauai Educational Association for Science & Astronomy Other features that are an entire region is absolute must to referred to by the check out in IC pachyderm 1396 are the proboscis phrase. many dark IC 1396 resides nebulae. Probably in the constellation the best is Cepheus and is Barnard 161. This located 2,400 light- dark nebula is years from Earth. located 15 To find IC 1396, arcminutes north start at Alpha of SAO 33652. Cephei, a.k.a. The nebula Alderamin, and go measures 5 by 2.5 five degrees arcminutes in southeast to the size. The nebula is fourth-magnitude very dark. Myriad red star Mu Cephei. Milky Way stars Mu Cephei goes by surround the the Arabic name nebula, but none Erakis. It is also can be seen in called Herschel’s this small patch of Garnet Star, after the sky.
    [Show full text]
  • STELLA Nummer 3 1992
    _ *S*T*E*L*L*A* är medlemstidningen UTGIVEN av och för STAR, Stockholms amatörastro- nomer. Tidningen UTKOMMER med ca 300 ex. 4 GGR/ÅR och erhålles gratis av medlemmar. i REDAKTÖRER och ansvariga utgivare är Hans Hellberg Jens Ergon Lofotengatan 16, Husby Kaggeholmsvägen 66 164 33 KISTA 122 40 ENSKEDE i ALLA BIDRAG AR VÄLKOMNA. men de skall helst vara utskrivna på elskrivmaskin, skön- eller laserskrivare. Red förbehåller sig att taga bort i eller redigera artiklar så att de passar det aktuella numret i samråd med förf. Ar du tveksam om materialet passar. ring och hör med red. Tala om hur du vill ha din artikel. ~k MEDLEM i STAR blir man genom att betala in ársavgiften till STAR'S postgiro 70 87 05 - 9. För l992 gäller följande avgifter: 75:- för dem som är under 26 är, 100:- för övriga. För ytterligare l00:- kan man även bli medlem av Svenska Astronomiska sällskapet och fà Astronomisk Tidsskrift. Detta förmånliga erbjudande gäller endast för STARmedlemmar, som betalar avgiften till STAR'S postgiro. Glöm ej att ange namm adress, samt om du är ny medlem. Å' STAR bildades 1988 och är en sammanslagning av tidigare astronomi- föreningar i Stockholm. STAR förfogar över tre OBSERVATORIER i Stockholmstrakten; i Djursholm. i Saltsjöbaden och i vàr KLUBBLOKAL, MAGNETHUSET på Observatoriekullen. STAR anordnar föredrag, bild: och filmvisningar. astronomiska observationer, astrofoto, teleskopbygge, vanlig mötesverksamhet m m. Pâ måndagar håller STAR, utom under helg eller lov, ÖPPET HUS i Magnethuset. på Observatoriekullen. kl l9,00. Har du frågor? Kom till oss eller skriv, via KLUBBENS ADRESS: STAR _ Gamla Observatoriet Drottning atan 120 113 60 OCKHOLM Ordförande; Mikael Jargelius Teknisk redaktör; Hans Hellberg Grafikv.
    [Show full text]
  • Astronomy Astrophysics
    A&A 433, 79–86 (2005) Astronomy DOI: 10.1051/0004-6361:20034537 & c ESO 2005 Astrophysics Asymmetrical structure of ionization and kinematics in the Seyfert galaxy NGC 5033 E. Mediavilla1, A. Guijarro2, A. Castillo-Morales3 , J. Jiménez-Vicente3, E. Florido3, S. Arribas4,, B. García-Lorenzo1, and E. Battaner3 1 Instituto de Astrofísica de Canarias, Tenerife, Spain e-mail: [email protected] 2 Centro Astronómico Hispano Alemán, Almería, Spain e-mail: [email protected] 3 Dpto. Física Teórica y del Cosmos, Universidad de Granada, Spain 4 Space Telescope Science Institute, Baltimore, USA Received 18 October 2003 / Accepted 29 November 2004 Abstract. We present integral field spectroscopy of NGC 5033, a low luminosity Seyfert galaxy. The observations were made with INTEGRAL, a fiber based system operating at the WHT. The intensity map of the Hβ emission line represents a spi- ral or ring-like pattern of HII regions. On the contrary, the [OIII] intensity map morphology is markedly anisotropic. The strong morphological differences imply that the [OIII] emitters represent highly ionized gas illuminated by the central source. The [OIII] map morphology is compatible with a biconical structure of ionization induced by strong extinction in the galaxy disc that also obscures half of the spheroidal stellar bulge. We identify the spectrum corresponding to the Seyfert 1 nucleus from the presence of Hβ broad emission lines. This spectrum is located in a region where strong extinction is expected but exhibits the bluest spectral energy distribution. The Seyfert 1 nucleus seems to be offcenter with respect to the stellar rotation center. This result has been also found in other Seyfert galaxies and interpreted in terms of a past merger.
    [Show full text]
  • Single Star – Sylvie D
    ASTRONOMY AND ASTROPHYSICS – Single Star – Sylvie D. Vauclair and Gerard P. Vauclair SINGLE STARS Sylvie D. Vauclair Institut de Recherches en Astronomie et Planétologie, Université de Toulouse, Institut Universitaire de France, 14 avenue Edouard Belin, 31400 Toulouse, France Gérard P. Vauclair Institut de Recherches en Astronomie et Planétologie, Université de Toulouse, Centre National de la Recherche Scientifique, 14 avenue Edouard Belin, 31400 Toulouse, France Keywords: stars, stellar structure, stellar evolution, magnitudes, HR diagrams, asteroseismology, planetary nebulae, White Dwarfs, supernovae Contents 1. Introduction 2. Stellar observational data 2.1. Distances 2.1.1. Direct Methods 2.1.2. Indirect Methods 2.2. Stellar Luminosities 2.2.1. Apparent Magnitude 2.2.2. Absolute Magnitude 2.3. Surface Temperatures 2.3.1. Brightness Temperatures 2.3.2 Color Temperatures, Color Indices 2.3.3 Effective Temperatures 2.4 Stellar Spectroscopy 2.4.1. Spectral Types 2.4.2. Chemical Composition 2.4.3. Stellar Rotation and Magnetic Fields 2.6. Masses and Radii 3. Stellar structure and evolution 3.1. Color-Magnitude Diagrams 3.2. Stellar Structure 3.2.1. CharacteristicUNESCO Stellar Time Scales – EOLSS 3.2.2. The Basic Equations of the Stellar Structure 3.2.3. ApproximateSAMPLE Solutions CHAPTERS 3.3. Stellar Evolution 3.3.1. Stellar Evolutionary Codes 3.3.2. Stellar Evolution before the Main Sequence 3.3.3 The Main Sequence 3.3.4 Post Main Sequence Tracks 3.3.5 HR Diagrams of Stellar Clusters 3.4. Stars and Stellar Environment: Recent Developments 3.4.1 Atomic Diffusion 3.4.2 Rotation and Rotational Braking ©Encyclopedia of Life Support Systems (EOLSS) ASTRONOMY AND ASTROPHYSICS – Single Star – Sylvie D.
    [Show full text]
  • The Heavens in August a Study of Short Period Variables
    100 SCIENTIFIC,AMERlCAN July 31, 1915 The Heavens in August A Study of Short Period Variables By Prof. Henry Norris Russell, Ph.D. HE warm clear nights of summer offer the amateur which is marked on our map, .and the second lies about and but 18 minutes of arc apart, while Neptune is only T the best chance for star-gazing in all the year, and, two fifths of the way from this to () Ophiuchi (also a degree away on the other side. This simultaneous fortunately, he has one of the finest portions of the shown on the map) and is the only bright star near conjunction of three planets is rather remarkable, but, heavens at his command in the splendid region of the this line. The character of the variation is in both as they rise less than an hour earlier than the Sun, Milky Way, which stretches from Cassiopeia and cases very similar to that of the stars previously de­ Neptune will be utterly invisible, though the other two Cygnus through Aquila to Sagittarius and Scorpio, and scribed. w Sagittarii varies from magnitude 4.3 to 5.1 planets may easily be seen with a telescope (provided forms a vast circle right across the summit of the vault in a period of 7.595 days, the ris� in brightness taking with suitable finding circles ) even in broad daylight, of heaven. about half as long as the fall, and the maximum being and in the same low-power field. The veriest novice can learn in an hour to identify a little more than twice the minimum light.
    [Show full text]
  • Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars
    Draft version September 13, 2019 Typeset using LATEX twocolumn style in AASTeX62 Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars Alexander P. Stephan,1, 2 Smadar Naoz,1, 2 B. Scott Gaudi,3 and Jesus M. Salas1, 2 1Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA 2Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles, Los Angeles, CA 90095, USA 3Department of Astronomy, The Ohio State University, Columbus, OH 43210, USA (Received XXX; Revised YYY; Accepted ZZZ) Submitted to ApJ ABSTRACT Exoplanets have been observed around stars at all stages of stellar evolution, in many cases orbiting in configurations that will eventually lead to the planets being engulfed or consumed by their host stars, such as Hot Jupiters or ultra-short period planets. Furthermore, objects such as polluted white dwarfs provide strong evidence that the consumption of planets by stars is a common phenomenon. This consumption causes several significant changes in the stellar properties, such as changes to the stellar spin, luminosity, chemical composition, or mass loss processes. Here, we explore this wide variety of effects for a comprehensive range of stellar and planetary masses and stages of stellar evolution, from the main sequence over red giants to the white dwarfs. We determine that planet consumption can cause transient luminosity features that last on the order of centuries to millennia, and that the post-consumption stellar spins can often reach break-up speeds. Furthermore, stellar moss loss can be caused by this spin-up, as well as through surface grazing interactions, leading to to the formation of unusual planetary nebula shapes or collimated stellar gas ejections.
    [Show full text]
  • 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].
    [Show full text]