DOCSLIB.ORG

Polarimetric Evolution of V838 Monocerotis?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Polarimetric Evolution of V838 Monocerotis? A&A 414, 591–600 (2004) Astronomy DOI: 10.1051/0004-6361:20031689 & c ESO 2004 Astrophysics Polarimetric evolution of V838 Monocerotis? S. Desidera1,E.Giro1, U. Munari2,Y.S.Efimov3,A.Henden4, S. Benetti1,T.Tomov5, A. Bianchini6, and C. Pernechele1 1 INAF – Osservatorio Astronomico di Padova, Vicolo dell’ Osservatorio 5, 35122, Padova, Italy 2 INAF – Osservatorio Astronomico di Padova - Sede di Asiago, 36012, Asiago, Italy 3 Crimean Astrophysical Observatory and Isaac Newton Institute of Chile, Crimean Branch, Ukraine 4 Universities Space Research Association/US Naval Observatory Flagstaff Station, PO Box 1149, Flagstaff AZ 86002-1149, USA 5 Centre for Astronomy Nicholaus Copernicus University, ul. Gagarina 11, 87-100 Torun, Poland 6 Universit´a di Padova, Dipartimento di Astronomia, Vicolo dell’Osservatorio 2, 35122, Padova, Italy Received 28 April 2003 / Accepted 30 September 2003 Abstract. We present the results of our polarimetric and spectropolarimetric monitoring of V838 Monocerotis, performed at the Asiago and Crimean observatories during and after the multiple outbursts that occurred in January March 2002. The polariza- tion of the object is mainly due to interstellar polarization (P 2:48%). Intrinsic polarization up to− 0.7% at 5000 Å is present ∼ ∼ during the second maximum of the object (February 2002). This intrinsic component increases toward shorter wavelengths but our limited spectral coverage (5000 7500 Å) does not allow conclusive inferences about its origin. A strong depolarization across the H profile is observed. The− interstellar polarization gives a lower limit to the reddening of E(B V) > 0:28, with α − E(B V) 0:5 being the most probable value. A normal ratio of total to selective absorption (RV = 3:22 0:17) was derived from− the wavelength∼ of maximum interstellar polarization. This suggests a low (if any) contribution by circumstellar± material with a peculiar dust to gas ratio. A polarimetric map of a portion of the light echo shows a complex polarization distribution reaching Pmax = 45%. Key words. stars: individual: V838Mon – techniques: polarimetric – stars: peculiar (except chemically peculiar) 1. Introduction M10-III (Desidera & Munari 2002). A faint blue continuum was found to dominate the spectrum blueward of 7000 Å, indi- V838 Monocerotis developed a spectacular multiple outburst cating a likely binary nature for the object. The hot component in January–March 2002, reaching V = 6:7. Its spectral char- was classified as B3V by Munari et al. (2002b). Bond et al. acteristics changed dramatically during its evolution. The pro- (2003) studied the light echo using the ACS onboard the HST. genitor had the temperature of a F star, while during the out- They found a lower limit to the distance of 6 kpc, implying burst V838 Mon evolved from a cool K giant to a late M giant. that V838 Mon at its maximum brightness was temporarily the The profile of spectral lines also changed during the outburst, brightest star in the Milky Way. and a strong Hα emission appeared during the second maxi- mum, when the object reached its peak visual magnitude. A In spite of these observational efforts the nature of prominent light echo was discovered by Henden et al. (2002). V838 Mon remains largely unknown. The evolution of V838 Mon from January to April 2002 is de- The study of the polarization can shed light on some phys- scribed by Munari et al. (2002a). Further photometric and spec- ical properties. On the one hand the interstellar polarization troscopic observations were presented by Kimeswenger et al. gives clues about the distance and the absorption towards the (2002), Goranskii et al. (2002), Kolev et al. (2002), Banerjee object. On the other hand, the presence of intrinsic polar- & Ashok (2002), Wisniewski et al. (2003), and Crause et al. ization, its wavelength dependence, its variations during the (2003). The first spectra obtained after the emersion from so- evolution of the object and the polarization across line pro- lar conjunction revealed a dramatic temperature decrease of files provide clues about the physics of the object. Wisniewski the object, whose spectrum became dominated by TiO and et al. (2003) present 2-epoch spectropolarimetric observations VO molecular bands, suggesting a spectral type later than of V838 Mon. They reveal the presence of intrinsic polariza- tion during the outburst, with variations across the profile of Send offprint requests to: S. Desidera, emission lines. e-mail: [email protected] ? Based on observations collected at Padua Astronomical Here we present the results of our more exten- Observatory at Asiago and Crimean Astrophysical Observatory. sive polarimetric and spectro-polarimetric monitoring of Article published by EDP Sciences and available at http://www.aanda.org or http://dx.doi.org/10.1051/0004-6361:20031689 592 S. Desidera et al.: Polarimetric evolution of V838 Monocerotis V838 Monocerotis, performed at the Asiago and Crimean ob- Table 1. Journal of observations. The grism is reported for spectropo- servatories from January to November 2002. The results pre- larimetric observations (#4, #7, #8, see text for details) and filter for sented here supersede the premininary analysis of part of the polarimetric photometry. A and C refer to Asiago and Crimean obser- same dataset included in Munari et al. (2002a). vations respectively. Target Date UT Grism/Filter Obs. 2. Observations V838 Mon 10/01/2002 23 40 4 A 2.1. Asiago V838 Mon 11/01/2002 23 10 4 A β Cas 11/01/2002 23 10 4 A Polarimetric and spectropolarimetric observations of V838 V838 Mon 04/02/2002 22 45 4,7,8 A Monocerotis were performed using the polarimetric mode of β Vir 05/02/2002 02 10 4,7,8 A AFOSC at the 1.82m telescope at Asiago Observatory (Italy). HD 93521 05/02/2002 03 40 4,7,8 A The AFOSC instrument is described by Desidera et al. (2002). V838 Mon 11/02/2002 18 40 U,B,V,R,I C The polarimeter is presented in detail elsewhere (Pernechele HD 42807 11/02/2002 19 30 8 A et al. 2003) and early results based on its use were presented V838 Mon 11/02/2002 21 10 8 A by Giro et al. (2003). Here we recall the main characteris- V838 Mon 15/02/2002 21 00 U,B,V,R,I C tics of the instrument. The AFOSC polarimeter consists of a V838 Mon 16/02/2002 20 10 U,B,V,R,I C double Wollaston prism which splits the incoming light into V838 Mon 18/02/2002 21 30 U,B,V,R,I C four polarized beams (at 0 ,90, 45 and 45 ) separated by V838 Mon 18/02/2002 21 50 4 A ◦ ◦ ◦ ◦ β Vir 18/02/2002 23 55 4 A 20 arcesc. These four beams are in− principle sufficient to de- V838 Mon 04/03/2002 21 30 4 A termine the first three elements of the Stokes vector, i.e. the V838 Mon 09/03/2002 20 00 U,B,V,R,I C intensity I and the two linear polarization parameters Q and U. V838 Mon 09/03/2002 21 00 8 A The Wollaston can be housed in the filter wheel or in the grism HD 114710 09/03/2002 02 05 8 A wheel of AFOSC. In the first case, spectropolarimetry can be V838 Mon 20/03/2002 19 10 B,V,I A performed by inserting a grism in the grism wheel, and in the HD 98421 20/03/2002 22 20 B,V,I A latter imaging or photo-polarimetry is obtained by inserting a HD 204847 29/10/2002 19 20 V A filter in the filter wheel. HD 14069 30/10/2002 00 25 V A For the spectropolarimetry, we used three different grisms: V838 Mon 30/10/2002 04 20 V A Grism #4, (wavelength range 4500 7800 Å; resolution HD 42807 09/11/2002 01 55 V A HD 43384 09/11/2002 02 20 V A 4.3 Å/pixel), Grism #7, (4350 6550 Å; 2.2− Å/pixel), Grism #8, V838 Mon 09/11/2002 03 50 V A (6250 8000 Å; 1.8 Å/pixel).− In all cases a slit 2.5 arcsec wide and 18− arcsec long was used. Our observational procedure includes spectra taken at po- sition angles of 0◦ and 90◦, to properly eliminate the spurious reflector at the Crimean astrophysical observatory (Ukraine), effects introduced by the different behaviour of the grism for using the computer controlled UBVRI Double Image Chopping the two polarimetric states. Flat fields were taken at both slit Photopolarimeter, developed at the Helsinki University obser- position angles (0◦ and 90◦) to avoid spurious polarization ef- vatory by V. Piirola (Piirola 1973, 1988). fects due to screen reflections. The instrument has two operational modes: photometric Observations were mostly performed in service mode as a mode with elimination of the background close to the object, target of opportunity, and this explains some inhomogeneities and two polarimetric modes to measure linear and/or circular of the instrument set-up used and, in some cases, the lack of polarization. In these modes the background is measured be- observations of standard stars. fore and after each set of observations of the object. An impor- The first spectropolarimetric observations were performed tant advantage is that the sky polarization is directly eliminated very early after the first maximum (January 10), and then we by using a plane parallel calcite plate as the polarizing beam continued our monitoring covering the relevant phases of the splitter. evolution of this peculiar object for nearly 2 months. In par- The measurements in different colors are performed si- ticular, the maximum of visual magnitude (Feb. 2002) is well multaneously using 5 photomultipliers and dichroic filters to covered by our observations.
Load more

Recommended publications
  • FY08 Technical Papers by GSMTPO Staff
    AURA/NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation July 23, 2008 Revised as Complete and Submitted December 23, 2008 NGC 660, ~13 Mpc from the Earth, is a peculiar, polar ring galaxy that resulted from two galaxies colliding. It consists of a nearly edge-on disk and a strongly warped outer disk. Image Credit: T.A. Rector/University of Alaska, Anchorage NATIONAL OPTICAL ASTRONOMY OBSERVATORY NOAO ANNUAL REPORT FY 2008 Submitted to the National Science Foundation December 23, 2008 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................................. 1 1 SCIENTIFIC ACTIVITIES AND FINDINGS ..................................................................................... 2 1.1 Cerro Tololo Inter-American Observatory...................................................................................... 2 The Once and Future Supernova η Carinae...................................................................................................... 2 A Stellar Merger and a Missing White Dwarf.................................................................................................. 3 Imaging the COSMOS...................................................................................................................................... 3 The Hubble Constant from a Gravitational Lens.............................................................................................. 4 A New Dwarf Nova in the Period Gap............................................................................................................
    [Show full text]
  • On the Progenitor of V838 Monocerotis
    A&A 441, 1099–1109 (2005) Astronomy DOI: 10.1051/0004-6361:20042485 & c ESO 2005 Astrophysics On the progenitor of V838 Monocerotis R. Tylenda1,3,N.Soker2, and R. Szczerba1 1 Department for Astrophysics, N. Copernicus Astronomical Center, Rabianska´ 8, 87-100 Torun,´ Poland e-mail: [tylenda;szczerba]@ncac.torun.pl 2 Department of Physics, Technion-Israel Institute of Technology, 32000 Haifa, Israel e-mail: [email protected] 3 Centre for Astronomy, N. Copernicus University, 87-100 Torun,´ Poland Received 6 December 2004 / Accepted 9 June 2005 ABSTRACT We summarize and analyze the available observational data on the progenitor and the environment of V838 Mon. From the available photometric data for the progenitor of V838 Mon we exclude the possibility that the object before eruption was an evolved red giant star (AGB or RGB star). We find that most likely it was a main sequence or pre-main sequence star of ∼5−10 M. From the light echo structure and evolution we conclude that the reflecting dust is of interstellar nature rather than blown by V838 Mon in the past. We discuss the IRAS and CO data for interstellar medium observed near the position of V838 Mon. Several interstellar molecular regions have radial velocities similar to that of V838 Mon, so dust seen in the light echo might be related to one of them. Key words. stars: early-type – stars: binaries: close – stars: circumstellar matter – stars: individual: V838 Mon – ISM: reflection nebulae – ISM: structure 1. Introduction binary system which can be an important fact for identifying the outburst mechanism.
    [Show full text]
  • V838 Monocerotis Revisited: Space Phenomenon Imitates Art
    HEIC0405: EMBARGOED UNTIL: 12:00 (CET)/6:00 (EST) 04 March, 2004 Photo release: V838 Monocerotis revisited: Space phenomenon imitates art 04-March-2004 "Starry Night", Vincent van Gogh's famous painting, is renowned for its bold whorls of light sweeping across a raging night sky. Although this image of the heavens came only from the artist's restless imagination, a new picture from the NASA/ESA Hubble Space Telescope bears remarkable similarities to the van Gogh work, complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space. This image, obtained with the Advanced Camera for Surveys on February 8, 2004, is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). The illumination of interstellar dust comes from the red supergiant star at the middle of the image, which gave off a flashbulb-like pulse of light two years ago. V838 Mon is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy. Called a light echo, the expanding illumination of a dusty cloud around the star has been revealing remarkable structures ever since the star suddenly brightened for several weeks in early 2002. Though Hubble has followed the light echo in several snapshots, this new image shows swirls or eddies in the dusty cloud for the first time. These eddies are probably caused by turbulence in the dust and gas around the star as they slowly expand away.
    [Show full text]
  • Hubble Space Telescope Observations of the Light Echoes Around V838 Monocerotis
    Asymmetric Planetary Nebulae III ASP Conference Series, Vol. XXX, 2004 M. Meixner, J. Kastner, B. Balick and N. Soker eds. Hubble Space Telescope Observations of the Light Echoes around V838 Monocerotis Howard E. Bond1, Arne Henden2, Zoltan G. Levay1, Nino Panagia1, William B. Sparks1, Sumner Starrfield3, R. Mark Wagner4, R. L. M. Corradi5, and U. Munari6 Abstract. The outburst of the unusual variable star V838 Monocero- tis is being accompanied by the most spectacular display of light echoes in the history of astronomy. We have imaged the echoes on 5 occasions in 2002 with the Hubble Space Telescope and its Advanced Camera for Surveys. Analysis of the angular expansion rates and polarimetry data yields a direct geometric distance (6 kpc), and establishes that the star was extremely luminous at the maximum of its outburst. Unlike a classi- cal nova, V838 Mon has remained a very cool red supergiant, and is now producing copious amounts of dust. The dust illuminated in the echoes was presumably ejected during previous similar outbursts. This event thus bears some similarities to the proto-PN ejection process from more normal AGB and post-AGB stars, and is of relevance to this conference. Light-echo imaging allows construction of fully 3-D maps of the dust dis- tribution, and we present a map based on these early observations. The dust is already seen to be highly non-spherical and non-homogeneous, similar to the structure inferred for many proto-PNe. 1. The Light-Echo Phenomenon A light echo is produced when a wave of illumination from a stellar outburst sweeps out into space.
    [Show full text]
  • The Infrared Evolution of Dust in V838 Monocerotis C
    Draft version August 19, 2021 Typeset using LATEX twocolumn style in AASTeX63 The Infrared Evolution of Dust in V838 Monocerotis C. E. Woodward ,1 A. Evans ,2 D. P. K. Banerjee ,3 T. Liimets ,4, 5 A. A. Djupvik ,6 S. Starrfield ,7 G. C. Clayton ,8 S. P. S. Eyres ,9 R. D. Gehrz ,1 and R. M. Wagner 10, 11 1Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455, USA 2Astrophysics Group, Keele University, Keele, Staffordshire, ST5 5BG, UK 3Physical Research Laboratory, Navrangpura, Ahmedabad, Gujarat 380009, India 4Astronomick´y´ustav,Akademie vˇed Cesk´erepubliky,ˇ v.v.i., Friˇcova298, 251 65 Ondˇrejov,Czech Republic 5Tartu Observatory, University of Tartu, Observatooriumi 1, 61602 T~oravere, Estonia 6Nordic Optical Telescope, Rambla Jos´eAna Fern´andezP´erez 7, ES-38711 Bre~naBaja, Spain 7School of Earth and Space Exploration, Arizona State University, Box 871404, Tempe, AZ 85287-1404, USA 8Louisiana State University, Baton Rouge, Department of Physics & Astronomy Baton Rouge, LA 70803-001, USA 9Faculty of Computing, Engineering & Science, University of South Wales, Pontypridd, CF37 1DL, UK 10Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210, USA 11Large Binocular Telescope Observatory, 933 North Cherry Avenue, Tucson, AZ 85721, USA (Received 2021 June 21; Accepted 2021 August 17; Published To Appear in The Astronomical Journal) ABSTRACT Luminous Red Variables (LRVs) are most likely eruptions that are the outcome of stellar mergers. V838 Mon is one of the best-studied members of this class, representing an archetype for stellar mergers resulting from B-type stars.
    [Show full text]
  • V838 Monocerotis: the Central Star and Its Environment a Decade After Outburst
    A&A 569, L3 (2014) Astronomy DOI: 10.1051/0004-6361/201424458 & c ESO 2014 Astrophysics Letter to the Editor V838 Monocerotis: the central star and its environment a decade after outburst O. Chesneau1, , F. Millour1,O.DeMarco2,S.N.Bright1,2,A.Spang1,D.P.K.Banerjee3,N.M.Ashok3, T. Kaminski´ 4,J.P.Wisniewski5, A. Meilland1, and E. Lagadec1, 1 Laboratoire Lagrange, UMR 7293, Univ. Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d’Azur, 06300 Nice, France e-mail: [email protected] 2 Department of Physics & Astronomy, Macquarie University, Sydney, NSW 2109, Australia 3 Physical Research Laboratory, Navrangpura, Ahmedabad, 380009 Gujarat, India 4 Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany 5 HL Dodge Department of Physics & Astronomy, University of Oklahoma, 440 W Brooks Street, Norman, OK 73019, USA Received 24 June 2014 / Accepted 21 July 2014 ABSTRACT Aims. V838 Monocerotis erupted in 2002, brightened in a series of outbursts, and eventually developed a spectacular light echo. A very red star emerged a few months after the outburst. The whole event has been interpreted as the result of a merger. Methods. We obtained near- and mid-IR interferometric observations of V838 Mon with the AMBER and MIDI recombiners located at the Very Large Telescope Interferometer (VLTI) array. The MIDI two-beam observations were obtained with the 8 m unit telescopes between October 2011 and February 2012. The AMBER three-beam observations were obtained with the compact array (B ≤ 35 m) in April 2013 and the long array (B ≤ 140 m) in May 2014, using the 1.8 m auxiliary telescopes.
    [Show full text]
  • Latest Views of the V838 Monocerotis Light Echo from Hubble 26 October 2006
    Latest views of the V838 Monocerotis light echo from Hubble 26 October 2006 The NASA/ESA Hubble Space Telescope has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique "thin-section" through the interstellar dust around the star. This release shows new images of the light echo from the Hubble Advanced Camera for Surveys taken in November 2005 (left) and again in September 2006 (right). The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars. The Hubble observations have been used to These images show the evolution of the light echo around the star V838 in the constellation of Monoceros. determine the distance to V838 Mon, using a They were taken by the Hubble Advanced Camera for technique based on the polarisation of the reflected Surveys in November 2005 (left) and again in light. Hubble has polarising filters that only pass September 2006 (right). The numerous whorls and light that vibrates at certain angles. This method eddies in the interstellar dust are particularly noticeable. yields a distance of 20,000 light-years for V838 Possibly they have been produced by the effects of Mon, suggesting that, during its outburst, V838 Mon magnetic fields in the space between the stars. Credit: was one of the brightest stars in the entire Milky NASA, ESA and H. Bond (STScI) Way. Although the reason for the eruption is still unclear, some astronomers have suggested it might have resulted from the collision of two stars.
    [Show full text]
  • The Continued Optical to Mid-Infrared Evolution of V838 Monocerotis* S
    The Astronomical Journal, 149:17 (8pp), 2015 January doi:10.1088/0004-6256/149/1/17 © 2015. The American Astronomical Society. All rights reserved. THE CONTINUED OPTICAL TO MID-INFRARED EVOLUTION OF V838 MONOCEROTIS* S. R. Loebman1,13, J. P. Wisniewski2,14, S. J. Schmidt3, A. F. Kowalski4, R. K. Barry5, K. S. Bjorkman6,14, H. B. Hammel7, S. L. Hawley8, L. Hebb9, M. M. Kasliwal10,15, D. K. Lynch11,14, R. W. Russell11,14, M. L. Sitko12,14,16, and P. Szkody8 1 Department of Astronomy, University of Michigan, 830 Dennison, 500 Church Street, Ann Arbor, MI 48109-1042, USA; [email protected] 2 Homer L. Dodge Department of Physics & Astronomy, The University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019, USA 3 Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210, USA 4 NASA Postdoctoral Program Fellow, NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771, USA 5 NASA Goddard Space Flight Center, Laboratory for Exoplanets & Stellar Astrophysics, Code 667, Greenbelt, MD 20771, USA 6 Ritter Observatory, MS #113, Department of Physics & Astronomy, University of Toledo, Toledo, OH 43606-3390, USA 7 AURA, 1212 New York Avenue NW, Suite 450, Washington, DC 20005, USA 8 Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195, USA 9 Department of Physics, Hobart & William Smith Colleges, 300 Pulteney Street, Geneva, NY 14456, USA 10 The Observatories, Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA 11 The Aerospace Corporation, M2-266, P.O. Box 92957, Los Angeles, CA 90009-29257, USA 12 Department of Physics, University of Cincinnati, Cincinnati OH 45221, USA Received 2014 June 19; accepted 2014 September 7; published 2014 December 15 ABSTRACT The eruptive variable V838 Monocerotis (V838 Mon) gained notoriety in 2002 when it brightened nine magnitudes in a series of three outbursts and then rapidly evolved into an extremely cool supergiant.
    [Show full text]
  • Discovery of Multiple Shells Around V838 Monocerotis
    A&A 427, 193–197 (2004) Astronomy DOI: 10.1051/0004-6361:20041388 & c ESO 2004 Astrophysics Discovery of multiple shells around V838 Monocerotis J. Th. van Loon, A. Evans, M. T. Rushton, and B. Smalley Astrophysics Group, School of Chemistry and Physics, Keele University, Staffordshire ST5 5BG, UK e-mail: [email protected] Received 15 April 2004 / Accepted 3 July 2004 Abstract. We report the discovery of multiple shells around the eruptive variable star V838 Mon. Two dust shells are seen in IRAS and MSX images, which themselves are situated in a shell of CO. This securely establishes V838 Mon as an evolved object. We revisit the light echo, which arises from scattering off the innermost resolved dust shell, to infer a distance to V838 Mon of ∼>5.5 kpc. The dynamical timescales of the ejected shells, location in the Milky Way and inferred luminosity are consistent with V838 Mon being a low-mass AGB star experiencing thermal pulses of which the 2002 eruption might have sent the star into the post-AGB phase. This scenario, however, is inconsistent with the presence of a (young and massive) B3 V companion. Key words. stars: AGB and post-AGB – stars: circumstellar matter – stars: distances – stars: individual: V838 Monocerotis – stars: mass-loss – stars: peculiar 1. Introduction interstellar medium, emits at far-IR wavelengths. The sky around V838 Mon is included in both the IRAS all sky survey V838 Monocerotis was discovered on January 6, 2002, (Brown (12, 25, 60 and 100 µm), and the Galactic plane survey by the 2002) as a new eruptive variable star, and peaked at m V MSX in several mid-IR bands of which band A (8.3 µm) was 7 mag on February 5, 2002.
    [Show full text]
  • Astronomy 2009 Index
    Astronomy Magazine 2009 Index Subject Index 1RXS J160929.1-210524 (star), 1:24 4C 60.07 (galaxy pair), 2:24 6dFGS (Six Degree Field Galaxy Survey), 8:18 21-centimeter (neutral hydrogen) tomography, 12:10 93 Minerva (asteroid), 12:18 2008 TC3 (asteroid), 1:24 2009 FH (asteroid), 7:19 A Abell 21 (Medusa Nebula), 3:70 Abell 1656 (Coma galaxy cluster), 3:8–9, 6:16 Allen Telescope Array (ATA) radio telescope, 12:10 ALMA (Atacama Large Millimeter/sub-millimeter Array), 4:21, 9:19 Alpha (α) Canis Majoris (Sirius) (star), 2:68, 10:77 Alpha (α) Orionis (star). See Betelgeuse (Alpha [α] Orionis) (star) Alpha Centauri (star), 2:78 amateur astronomy, 10:18, 11:48–53, 12:19, 56 Andromeda Galaxy (M31) merging with Milky Way, 3:51 midpoint between Milky Way Galaxy and, 1:62–63 ultraviolet images of, 12:22 Antarctic Neumayer Station III, 6:19 Anthe (moon of Saturn), 1:21 Aperture Spherical Telescope (FAST), 4:24 APEX (Atacama Pathfinder Experiment) radio telescope, 3:19 Apollo missions, 8:19 AR11005 (sunspot group), 11:79 Arches Cluster, 10:22 Ares launch system, 1:37, 3:19, 9:19 Ariane 5 rocket, 4:21 Arianespace SA, 4:21 Armstrong, Neil A., 2:20 Arp 147 (galaxy pair), 2:20 Arp 194 (galaxy group), 8:21 art, cosmology-inspired, 5:10 ASPERA (Astroparticle European Research Area), 1:26 asteroids. See also names of specific asteroids binary, 1:32–33 close approach to Earth, 6:22, 7:19 collision with Jupiter, 11:20 collisions with Earth, 1:24 composition of, 10:55 discovery of, 5:21 effect of environment on surface of, 8:22 measuring distant, 6:23 moons orbiting,
    [Show full text]
  • V838 Monocerotis As Seen by ALMA: a Remnant of a Binary Merger
    Astronomy & Astrophysics manuscript no. V838ALMAdust ©ESO 2021 June 15, 2021 V838 Monocerotis as seen by ALMA: a remnant of a binary merger in a triple system Tomek Kaminski´ 1, Romuald Tylenda1, Aleksandra Kiljan2, Mirek Schmidt1, Krzysztof Lisiecki3, Carl Melis4, Adam Frankowski1, Vishal Joshi5, and Karl M. Menten6 1 Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Rabianska´ 8, 87-100 Torun,´ e-mail: [email protected] 2 Warsaw University Astronomical Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland 3 Institute of Astronomy, Nicolaus Copernicus University in Torun,´ Grudzi˛adzka5, 87-100 Torun,´ Poland 4 Center for Astrophysics and Space Sciences, University of California, San Diego, CA 92093-0424, USA 5 Physical Research Laboratory, Navrangpura, Ahmedabad, Gujarat 380009, India 6 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53-121 Bonn, Germany June 15, 2021 ABSTRACT Context. V838 Mon erupted in 2002 quickly becoming the prototype of a new type of stellar eruptions known today as (luminous) red novae. The red nova outbursts are thought to be caused by stellar mergers. The merger in V838 Mon took place in a triple or higher system involving two B-type stars. Aims. We wish to characterize the merger remnant ∼17 yr after the eruption to learn more about the remaining system, the progenitor, and merger physics. Methods. We mapped the merger site with ALMA at a resolution of ∼25 mas, or 148 au for a distance of 5.9 kpc, in continuum dust emission and in rotational lines of simple molecules, including CO, SiO, SO, SO2, AlOH, and H2S. We use radiative transfer calculations to reproduce the remnant’s architecture at the epoch of the ALMA observations.
    [Show full text]
  • Observing the Luminosity Increase and Roche Lobe Overflow of Planet Destruction
    Observing the Luminosity Increase and Roche Lobe Overflow of Planet Destruction Stuart F. Taylor1,2 Department of Physics and Institute of Astronomy, National Tsing Hua University, Hsinchu, Taiwan ABSTRACT The destruction of planets by migration into the star will release significant amounts of energy and material, which will present opportunities to observational study planets in new ways. To observe planet destruction, it is important to understand the processes of how this energy and material is released as planets are destroyed. It is not known how fast the large amounts of energy and material are released, making it difficult to predict how observable planet destruction will be. There is a huge amount of energy made available by falling deep into the star’s potential well: Simple calculations show that many of the currently known“hot Jupiters” can potentially produce events as luminous as a small nova if the energy is released fast enough. To observe these events, the important questions are how will this energy be released, and whether the energy will be released rapidly enough to create an event luminous enough to be found by transient surveys. Even the final rapid tidal infall of the planet may input enough energy into the star that could rival the energy output of the star. The final destruction will release even far more energy. These events are rare enough to explain why there is no undisputed observation of planet accretion, but future transient astronomy surveys such as PTF, Pan-STARRS, and LSST may have a good chance of catching planet destruction events. Alternatively, if planet destruction is slowed by the inward migration alternating with periods of outward migration caused by Roche lobe overflow (RLOF), then the primary signature may be the effects of the release of large amounts of gas.
    [Show full text]