Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau
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Chemical Evolution of Protoplanetary Disks-The Effects of Viscous Accretion, Turbulent Mixing and Disk Winds
Draft version June 5, 2018 Preprint typeset using LATEX style emulateapj v. 11/10/09 CHEMICAL EVOLUTION OF PROTOPLANETARY DISKS – THE EFFECTS OF VISCOUS ACCRETION, TURBULENT MIXING AND DISK WINDS D. Heinzeller1 and H. Nomura Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan and C. Walsh and T. J. Millar Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN, UK Draft version June 5, 2018 ABSTRACT We calculate the chemical evolution of protoplanetary disks considering radial viscous accretion, vertical turbulent mixing and vertical disk winds. We study the effects on the disk chemical structure when different models for the formation of molecular hydrogen on dust grains are adopted. Our gas- phase chemistry is extracted from the UMIST Database for Astrochemistry (Rate06) to which we have added detailed gas-grain interactions. We use our chemical model results to generate synthetic near- and mid-infrared LTE line emission spectra and compare these with recent Spitzer observations. Our results show that if H2 formation on warm grains is taken into consideration, the H2O and OH abundances in the disk surface increase significantly. We find the radial accretion flow strongly influences the molecular abundances, with those in the cold midplane layers particularly affected. On the other hand, we show that diffusive turbulent mixing affects the disk chemistry in the warm molecular layers, influencing the line emission from the disk and subsequently improving agreement with observations. We find that NH3, CH3OH, C2H2 and sulphur-containing species are greatly enhanced by the inclusion of turbulent mixing. -
The Dunhuang Chinese Sky: a Comprehensive Study of the Oldest Known Star Atlas
25/02/09JAHH/v4 1 THE DUNHUANG CHINESE SKY: A COMPREHENSIVE STUDY OF THE OLDEST KNOWN STAR ATLAS JEAN-MARC BONNET-BIDAUD Commissariat à l’Energie Atomique ,Centre de Saclay, F-91191 Gif-sur-Yvette, France E-mail: [email protected] FRANÇOISE PRADERIE Observatoire de Paris, 61 Avenue de l’Observatoire, F- 75014 Paris, France E-mail: [email protected] and SUSAN WHITFIELD The British Library, 96 Euston Road, London NW1 2DB, UK E-mail: [email protected] Abstract: This paper presents an analysis of the star atlas included in the medieval Chinese manuscript (Or.8210/S.3326), discovered in 1907 by the archaeologist Aurel Stein at the Silk Road town of Dunhuang and now held in the British Library. Although partially studied by a few Chinese scholars, it has never been fully displayed and discussed in the Western world. This set of sky maps (12 hour angle maps in quasi-cylindrical projection and a circumpolar map in azimuthal projection), displaying the full sky visible from the Northern hemisphere, is up to now the oldest complete preserved star atlas from any civilisation. It is also the first known pictorial representation of the quasi-totality of the Chinese constellations. This paper describes the history of the physical object – a roll of thin paper drawn with ink. We analyse the stellar content of each map (1339 stars, 257 asterisms) and the texts associated with the maps. We establish the precision with which the maps are drawn (1.5 to 4° for the brightest stars) and examine the type of projections used. -
Frankfurt Pleiades Star Map 2
FRANKFURT PLEIADES STAR MAP 2 In investigating the Martian connection of the Pleiadian pattern of Frankfurt, one cannot avoid to address the origins at least in the propagation of this motif in the modern era and in all the financial powerhouses of today’s World Financial Oder. This is in part the Pleiades conspiracy as this modern version of the ‘Pleiadian Conspiracy’ started here in Frankfurt with the Rothschild dynasty by Amschel Moses Bauer, 1743. This critique is not meant to placate all those of the said family or those that work in such financial structures or businesses and specifically not those in Frankfurt. However the argument is that those behind the family apparatus are of a cabal that is connected to the allegiance of not the true GOD of the Universe, YHVH but to the false usurper Lucifer. It is Lucifer they worship and venerate as the ‘god of this world’ and is the God of Mammon according to Jesus’ assessment. According to research and especially based on The 13 Bloodlines of the Illuminati by Springmeier, the current financial domination of the world began in Frankfurt with Mayer Amschel. They were of Jewish extract but adhere more toward the Kabbalistic, Zohar, and ancient Babylonian secret mystery religion initiated by Nimrod after the Flood of Noah. The star Taygete corresponds to the Literaturahaus building. T he star Celaena corresponds to the Burgenamt Zentrales building. The star Merope corresponds to the area of the Timmitus und THE PLEIADES Hyperakusis Center. The star Alcyone corresponds to the Oper FINANCIAL DISTRICT The Bearing-Point building is Frankfurt or the Opera House. -
Winter Observing Notes
Wynyard Planetarium & Observatory Winter Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Tour of the Sky with the Naked Eye NGC 457 CASSIOPEIA eta Cas Look for Notice how the constellations 5 the ‘W’ swing around Polaris during shape the night Is Dubhe yellowish compared 2 Polaris to Merak? Dubhe 3 Merak URSA MINOR Kochab 1 Is Kochab orange Pherkad compared to Polaris? THE PLOUGH 4 Mizar Alcor Figure 1: Sketch of the northern sky in winter. North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. To your right is a group of stars like the outline of a saucepan standing up on it’s handle. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The top two stars are called the Pointers. Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white-hot. 2. Use the Pointers to guide you to the left, to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the right are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris. Check with binoculars. © Rob Peeling, CaDAS, 2007 version 2.0 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Winter Polaris, Kochab and Pherkad mark the constellation Ursa Minor, the Little Bear. -
Optical Spectroscopic Monitoring Observations of a T Tauri Star V409
International Journal of Astronomy & Astrophysics, 2019, *,** Published Online **** 2019 in SciRes. http://www.scirp.org/journal/**** http://dx.doi.org/10.4236/****.2014.***** Optical Spectroscopic Monitoring Observations of a T Tauri Star V409 Tau Hinako Akimoto1 and Yoichi Itoh1 1 Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Sayo, Hyogo 679-5313, Japan Email: [email protected] Received **** 2019 Copyright c 2019 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract We report the results of optical spectroscopic monitoring observations of a T Tauri star, V409 Tau. A previous photometric study indicated that this star experienced dimming events due to the obscuration of light from the central star with a distorted circumstellar disk. We conducted medium-resolution (R ∼ 10000) spectroscopic observations with 2-m Nayuta telescope at Nishi-Harima Astronomical Observatory. Spectra were obtained in 18 nights between November 2015 and March 2016. Several absorption lines such as Ca I and Li, and the Hα emission line were confirmed in the spectra. The Ic-band magnitudes of V409 Tau changed by approximately 1 magnitude during the observation epoch. The equivalent widths of the five absorption lines are roughly constant despite changes in the Ic-band magnitudes. We conclude that the light variation of the star is caused by the obscuration of light from the central star with a distorted circumstellar disk, based on the relationship between the equivalent widths of the absorption lines and the Ic-band magnitudes. -
Discovery of Variable X-Ray Absorption in the Ctts AA Tauri J
A&A 462, L41–L44 (2007) Astronomy DOI: 10.1051/0004-6361:20066693 & c ESO 2007 Astrophysics Letter to the Editor Discovery of variable X-ray absorption in the cTTS AA Tauri J. H. M. M. Schmitt and J. Robrade Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany e-mail: [email protected] Received 3 November 2006 / Accepted 6 December 2006 ABSTRACT We present XMM-Newton X-ray and UV observations of the classical T Tauri star AA Tau covering almost two rotational periods where Prot ∼ 8.5 days. Clear, but uncorrelated variability is found at both wavebands. The variability observed at ∼2100 Å follows the previously known optical period. Spectral analysis of the X-ray data results in significant variability in the X-ray absorption such that the times of maximal X-ray absorption and UV extinction coincide. Placing the coronal emission in regions at low up to moderate magnetic latitudes and attribution of the variable X-ray absorption to accretion curtains and/or the disk warp provides a consistent physical picture. However, the derived X-ray absorption and optical extinction at times of maximal optical/UV brightness, i.e. outside occultation, are difficult to reconcile, requiring additional absorption in a disk wind or a peculiar dust grain distribution. Key words. X-rays: stars – stars: pre-main sequence – stars: coronae – stars: activity 1. Introduction warp leads to a partial occultation of AA Tau’s photosphere, thus causing the observed almost achromatic brightness variations. T Tauri stars (TTS) are very young low-mass stars evolving to- Polarization measurements (Ménard et al. -
Why Are There Seven Sisters?
Why are there Seven Sisters? Ray P. Norris1,2 & Barnaby R. M. Norris3,4,5 1 Western Sydney University, Locked Bag 1797, Penrith South, NSW 1797, Australia 2 CSIRO Astronomy & Space Science, PO Box 76, Epping, NSW 1710, Australia 3 Sydney Institute for Astronomy, School of Physics, Physics Road, University of Sydney, NSW 2006, Australia 4 Sydney Astrophotonic Instrumentation Laboratories, Physics Road, University of Sydney, NSW 2006, Australia 5 AAO-USyd, School of Physics, University of Sydney, NSW 2006, Australia Abstract of six stars arranged symmetrically around a seventh, and is There are two puzzles surrounding the therefore probably symbolic rather than a literal picture of Pleiades, or Seven Sisters. First, why are the Pleiades. the mythological stories surrounding them, In Greek mythology, the Seven Sisters are named after typically involving seven young girls be- the Pleiades, who were the daughters of Atlas and Pleione. ing chased by a man associated with the Their father, Atlas, was forced to hold up the sky, and was constellation Orion, so similar in vastly sep- therefore unable to protect his daughters. But to save them arated cultures, such as the Australian Abo- from being raped by Orion the hunter, Zeus transformed them riginal cultures and Greek mythology? Sec- into stars. Orion was the son of Poseidon, the King of the sea, ond, why do most cultures call them “Seven and a Cretan princess. Orion first appears in ancient Greek Sisters" even though most people with good calendars (e.g. Planeaux , 2006), but by the late eighth to eyesight see only six stars? Here we show that both these puzzles may be explained by early seventh centuries BC, he is said to be making unwanted a combination of the great antiquity of the advances on the Pleiades (Hesiod, Works and Days, 618-623). -
Hans Moritz Günther
page 1 of 3 Hans Moritz G¨unther - List of publications Refereed publications First author publications 16. YSOVAR: Mid-infrared Variability in the Star-forming Region Lynds 1688 H. M. G¨unther, A. M. Cody, K. R. Covey, L. A. Hillenbrand, P. Plavchan, K. Poppenhaeger, L. M. Rebull, J. R. Stauffer, S. J. Wolk, L. Allen, A. Bayo, R. A. Gutermuth, J. L. Hora, H. Y. A. Meng, M. Morales-Calder´on,J. R. Parks, Insoek Song (2014), AJ 148, 122 15. Recollimation Boundary Layers as X-Ray Sources in Young Stellar Jets H. M. G¨unther, Zhi-Yun Li, P. C. Schneider (2014), ApJ, 795, 51 14. MN Lup: X-rays from a Weakly Accreting T Tauri Star H. M. G¨unther, U. Wolter, J. Robrade, S. J. Wolk (2013), ApJ 771, 70 13. The evolution of the jet from the Herbig Ae Star HD 163296 in the last decade H. M. G¨unther, P. C. Schneider, Z.-Y. Li (2013), A&A 552, 142 12. Accretion, winds and outflows in young stars H. M. G¨unther (2013), AN 334, 67 11. IRAS 20050+2720: Anatomy of a Young Stellar Cluster H. M. G¨unther, S. J. Wolk, B. Spitzbart, R. A. Gutermuth, J. Forbrich, N. J. Wright, L. Allen, T. L. Bourke, S. T. Megeath, J. L. Pipher (2012), AJ 144, 101 10. Soft Coronal X-Rays from β Pictoris H. M. G¨unther, S. J. Wolk, J. J. Drake, C. M. Lisse,J. Robrade, J. H. M. M. Schmitt (2012), ApJ 750, 78 9. Accretion, jets and winds: High-energy emission from young stellar objects H. -
The Annual Compendium of Commercial Space Transportation: 2017
Federal Aviation Administration The Annual Compendium of Commercial Space Transportation: 2017 January 2017 Annual Compendium of Commercial Space Transportation: 2017 i Contents About the FAA Office of Commercial Space Transportation The Federal Aviation Administration’s Office of Commercial Space Transportation (FAA AST) licenses and regulates U.S. commercial space launch and reentry activity, as well as the operation of non-federal launch and reentry sites, as authorized by Executive Order 12465 and Title 51 United States Code, Subtitle V, Chapter 509 (formerly the Commercial Space Launch Act). FAA AST’s mission is to ensure public health and safety and the safety of property while protecting the national security and foreign policy interests of the United States during commercial launch and reentry operations. In addition, FAA AST is directed to encourage, facilitate, and promote commercial space launches and reentries. Additional information concerning commercial space transportation can be found on FAA AST’s website: http://www.faa.gov/go/ast Cover art: Phil Smith, The Tauri Group (2017) Publication produced for FAA AST by The Tauri Group under contract. NOTICE Use of trade names or names of manufacturers in this document does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the Federal Aviation Administration. ii Annual Compendium of Commercial Space Transportation: 2017 GENERAL CONTENTS Executive Summary 1 Introduction 5 Launch Vehicles 9 Launch and Reentry Sites 21 Payloads 35 2016 Launch Events 39 2017 Annual Commercial Space Transportation Forecast 45 Space Transportation Law and Policy 83 Appendices 89 Orbital Launch Vehicle Fact Sheets 100 iii Contents DETAILED CONTENTS EXECUTIVE SUMMARY . -
The Herschel-SPIRE Legacy Survey (HSLS): the Scientific Goals of A
The Herschel-SPIRE Legacy Survey (HSLS) The Scientific Goals of a Shallow and Wide Submillimeter Imaging Survey with SPIRE Members of the HSLS Study Team Asantha Cooray1, Steve Eales2, Scott Chapman14, David L. Clements4, Olivier Dor´e5, Duncan Farrah6, Matt J. Jarvis8 Manoj Kaplinghat1, Mattia Negrello3, Alessandro Melchiorri9, Hiranya Peiris11, Alexandra Pope12, Mario G. Santos13, Stephen Serjeant3, Mark Thompson8, Glenn White3,15, Alexandre Amblard1,7, Manda Banerji14, Pier-Stefano Corasaniti16, Sudeep Das17, Francesco de Bernardis9, Gianfranco de Zotti78, Tommaso Giannantonio18,88, Joaquin Gonzalez-Nuevo Gonzalez19, Ali Ahmad Khostovan1, Ketron Mitchell- Wynne1, Paolo Serra1, Yong-Seon Song20, Joaquin Vieira86, Lingyu Wang6, Michael Zemcov86,5 Filipe Abdalla11, Jose Afonso56, Nabila Aghanim49, Paola Andreani21, Itziar Aretxaga84, Robbie Auld2, Maarten Baes85, Andrew Baker58, Denis Barkats68, R. Belen Barreiro60, Nicola Bartolo89, Elizabeth Barton1, Sudhan- shu Barway23, Elia Stefano Battistelli9, Carlton Baugh25, Alexander Beelen49, Karim Benabed49, Andrew Blain86, Joss Bland-Hawthorn46, James J. Bock5,86, J. Richard Bond40, Julian Borrill22,41, Colin Borys67, Alessandro Boselli51, Fran¸cois R. Bouchet79, Carrie Bridge86, Fabrizio Brighenti96, Veronique Buat51, David Buote1, Denis Burgarella51, Robert Bussmann39, Erminia Calabrese9, Christopher Cantalupo22, Raymond Carlberg38, Carla Sofia Carvalho63, Caitlin Casey100, Antonio Cava47,77, Jordi Cepa47, Edward Chapin37, Ranga Ram Chary86, Xuelei Chen87, Natalie Christopher35, Sergio Colafrancesco62,78, Shaun Cole25, Peter Coles2, Alexander Conley93, Luca Conversi74, Jeff Cooke1, Steven Crawford23, Catherine Cress91, Elisa- bete da Cunha95, Gavin Dalton15,35, Luigi Danese19, Helmut Dannerbauer80, Jonathan Davies2, Paolo de Bernardis9, Roland de Putter70, Mark Devlin33, Jose M. Diego60, Herv´eDole49, Marian Douspis49, Joanna Dunkley35, James Dunlop54, Loretta Dunne31, Rolando D¨unner105, Simon Dye2, George Efstathiou102, Ei- ichi Egami39, Taotao Fang1, Patrizia Ferrero47,77, Alberto Franceschini71, Christopher C. -
The Pleiades: the Celestial Herd of Ancient Timekeepers
The Pleiades: the celestial herd of ancient timekeepers. Amelia Sparavigna Dipartimento di Fisica, Politecnico di Torino C.so Duca degli Abruzzi 24, Torino, Italy Abstract In the ancient Egypt seven goddesses, represented by seven cows, composed the celestial herd that provides the nourishment to her worshippers. This herd is observed in the sky as a group of stars, the Pleiades, close to Aldebaran, the main star in the Taurus constellation. For many ancient populations, Pleiades were relevant stars and their rising was marked as a special time of the year. In this paper, we will discuss the presence of these stars in ancient cultures. Moreover, we will report some results of archeoastronomy on the role for timekeeping of these stars, results which show that for hunter-gatherers at Palaeolithic times, they were linked to the seasonal cycles of aurochs. 1. Introduction Archeoastronomy studies astronomical practices and related mythologies of the ancient cultures, to understand how past peoples observed and used the celestial phenomena and what was the role played by the sky in their cultures. This discipline is then a branch of the cultural astronomy, an interdisciplinary field that relates astronomical phenomena to current and ancient cultures. It must then be distinguished from the history of astronomy, because astronomy is a culturally specific concept and ancient peoples may have been related to the sky in different way [1,2]. Archeoastronomy is considered as a quite new interdisciplinary science, rooted in the Stonehenge studies of 1960s by the astronomer Gerald Hawkins, who tested Stonehenge alignments by computer, and concluded that these stones marked key dates in the megalithic calendar [3]. -
00E the Construction of the Universe Symphony
The basic construction of the Universe Symphony. There are 30 asterisms (Suites) in the Universe Symphony. I divided the asterisms into 15 groups. The asterisms in the same group, lay close to each other. Asterisms!! in Constellation!Stars!Objects nearby 01 The W!!!Cassiopeia!!Segin !!!!!!!Ruchbah !!!!!!!Marj !!!!!!!Schedar !!!!!!!Caph !!!!!!!!!Sailboat Cluster !!!!!!!!!Gamma Cassiopeia Nebula !!!!!!!!!NGC 129 !!!!!!!!!M 103 !!!!!!!!!NGC 637 !!!!!!!!!NGC 654 !!!!!!!!!NGC 659 !!!!!!!!!PacMan Nebula !!!!!!!!!Owl Cluster !!!!!!!!!NGC 663 Asterisms!! in Constellation!Stars!!Objects nearby 02 Northern Fly!!Aries!!!41 Arietis !!!!!!!39 Arietis!!! !!!!!!!35 Arietis !!!!!!!!!!NGC 1056 02 Whale’s Head!!Cetus!! ! Menkar !!!!!!!Lambda Ceti! !!!!!!!Mu Ceti !!!!!!!Xi2 Ceti !!!!!!!Kaffalijidhma !!!!!!!!!!IC 302 !!!!!!!!!!NGC 990 !!!!!!!!!!NGC 1024 !!!!!!!!!!NGC 1026 !!!!!!!!!!NGC 1070 !!!!!!!!!!NGC 1085 !!!!!!!!!!NGC 1107 !!!!!!!!!!NGC 1137 !!!!!!!!!!NGC 1143 !!!!!!!!!!NGC 1144 !!!!!!!!!!NGC 1153 Asterisms!! in Constellation Stars!!Objects nearby 03 Hyades!!!Taurus! Aldebaran !!!!!! Theta 2 Tauri !!!!!! Gamma Tauri !!!!!! Delta 1 Tauri !!!!!! Epsilon Tauri !!!!!!!!!Struve’s Lost Nebula !!!!!!!!!Hind’s Variable Nebula !!!!!!!!!IC 374 03 Kids!!!Auriga! Almaaz !!!!!! Hoedus II !!!!!! Hoedus I !!!!!!!!!The Kite Cluster !!!!!!!!!IC 397 03 Pleiades!! ! Taurus! Pleione (Seven Sisters)!! ! ! Atlas !!!!!! Alcyone !!!!!! Merope !!!!!! Electra !!!!!! Celaeno !!!!!! Taygeta !!!!!! Asterope !!!!!! Maia !!!!!!!!!Maia Nebula !!!!!!!!!Merope Nebula !!!!!!!!!Merope