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Radio and IR Interferometry of Sio Maser Stars
Cosmic Masers - from OH to H0 Proceedings IAU Symposium No. 287, 2012 c International Astronomical Union 2012 R.S. Booth, E.M.L. Humphreys & W.H.T. Vlemmings, eds. doi:10.1017/S1743921312006989 Radio and IR interferometry of SiO maser stars Markus Wittkowski1, David A. Boboltz2,MalcolmD.Gray3, Elizabeth M. L. Humphreys1 Iva Karovicova4, and Michael Scholz5,6 1 ESO, Karl-Schwarzschild-Str. 2, 85748 Garching bei M¨unchen, Germany 2 US Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420, USA 3 Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL, UK 4 Max-Planck-Institut f¨ur Astronomie, K¨onigstuhl 17, 69117 Heidelberg, Germany 5 Zentrum f¨ur Astronomie der Universit¨at Heidelberg (ZAH), Institut f¨ur Theoretische Astrophysik, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany 6 Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney NSW 2006, Australia Abstract. Radio and infrared interferometry of SiO maser stars provide complementary infor- mation on the atmosphere and circumstellar environment at comparable spatial resolution. Here, we present the latest results on the atmospheric structure and the dust condensation region of AGB stars based on our recent infrared spectro-interferometric observations, which represent the environment of SiO masers. We discuss, as an example, new results from simultaneous VLTI and VLBA observations of the Mira variable AGB star R Cnc, including VLTI near- and mid- infrared interferometry, as well as VLBA observations of the SiO maser emission toward this source. We present preliminary results from a monitoring campaign of high-frequency SiO maser emission toward evolved stars obtained with the APEX telescope, which also serves as a pre- cursor of ALMA images of the SiO emitting region. -
Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Evidence for Very Extended Gaseous Layers Around O-Rich Mira Variables and M Giants B
The Astrophysical Journal, 579:446–454, 2002 November 1 # 2002. The American Astronomical Society. All rights reserved. Printed in U.S.A. EVIDENCE FOR VERY EXTENDED GASEOUS LAYERS AROUND O-RICH MIRA VARIABLES AND M GIANTS B. Mennesson,1 G. Perrin,2 G. Chagnon,2 V. Coude du Foresto,2 S. Ridgway,3 A. Merand,2 P. Salome,2 P. Borde,2 W. Cotton,4 S. Morel,5 P. Kervella,5 W. Traub,6 and M. Lacasse6 Received 2002 March 15; accepted 2002 July 3 ABSTRACT Nine bright O-rich Mira stars and five semiregular variable cool M giants have been observed with the Infrared and Optical Telescope Array (IOTA) interferometer in both K0 (2.15 lm) and L0 (3.8 lm) broad- band filters, in most cases at very close variability phases. All of the sample Mira stars and four of the semire- gular M giants show strong increases, from ’20% to ’100%, in measured uniform-disk (UD) diameters between the K0 and L0 bands. (A selection of hotter M stars does not show such a large increase.) There is no evidence that K0 and L0 broadband visibility measurements should be dominated by strong molecular bands, and cool expanding dust shells already detected around some of these objects are also found to be poor candi- dates for producing these large apparent diameter increases. Therefore, we propose that this must be a con- tinuum or pseudocontinuum opacity effect. Such an apparent enlargement can be reproduced using a simple two-component model consisting of a warm (1500–2000 K), extended (up to ’3 stellar radii), optically thin ( ’ 0:5) layer located above the classical photosphere. -
Where Are the Distant Worlds? Star Maps
W here Are the Distant Worlds? Star Maps Abo ut the Activity Whe re are the distant worlds in the night sky? Use a star map to find constellations and to identify stars with extrasolar planets. (Northern Hemisphere only, naked eye) Topics Covered • How to find Constellations • Where we have found planets around other stars Participants Adults, teens, families with children 8 years and up If a school/youth group, 10 years and older 1 to 4 participants per map Materials Needed Location and Timing • Current month's Star Map for the Use this activity at a star party on a public (included) dark, clear night. Timing depends only • At least one set Planetary on how long you want to observe. Postcards with Key (included) • A small (red) flashlight • (Optional) Print list of Visible Stars with Planets (included) Included in This Packet Page Detailed Activity Description 2 Helpful Hints 4 Background Information 5 Planetary Postcards 7 Key Planetary Postcards 9 Star Maps 20 Visible Stars With Planets 33 © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Detailed Activity Description Leader’s Role Participants’ Roles (Anticipated) Introduction: To Ask: Who has heard that scientists have found planets around stars other than our own Sun? How many of these stars might you think have been found? Anyone ever see a star that has planets around it? (our own Sun, some may know of other stars) We can’t see the planets around other stars, but we can see the star. -
Binocular Universe: Sly Fox September 2010 Phil Harrington
Binocular Universe is available every month on Cloudynights.com Binocular Universe: Sly Fox September 2010 Phil Harrington ast month's Stellafane convention, held atop Breezy Hill outside of Springfield, Vermont, was the best in recent memory. The skies were the Lclearest we've had in years, giving us a chance to enjoy the beauty of the summer Milky Way, which stretched from horizon to horizon. Armed with my trusty 10x50 and 16x70 binoculars, I sat back in my reclining chair and swept the plane of our Galaxy in pursuit of some old friends and new conquests. Above: Summer star map from Star Watch by Phil Harrington Binocular Universe is available every month on Cloudynights.com Above: Finder chart for this month's Binocular Universe. Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm Binocular Universe is available every month on Cloudynights.com Here are a few gems I bumped into along the way as I viewed the tiny constellation of Vulpecula the Fox. Vulpecula is a faint summertime constellation wedged between Cygnus (the Swan) to the north and Sagitta (the Arrow) to the south. None of Vulpecula’s stars shine brighter than magnitude 4.5, so seeing a fox here is a tall order indeed. But the sly Fox holds many binocular treasures for those who the time to seek them out. Vulpecula was created in 1687 by the Polish astronomer Johannes Hevelius. His original drawing showed a small fox carrying a hapless goose in its mouth. He called the combination Vulpecula et Anser ("the little fox and the goose"). -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
Occurrence and Core-Envelope Structure of 1–4× Earth-Size Planets Around Sun-Like Stars
Occurrence and core-envelope structure of 1–4× SPECIAL FEATURE Earth-size planets around Sun-like stars Geoffrey W. Marcya,1, Lauren M. Weissa, Erik A. Petiguraa, Howard Isaacsona, Andrew W. Howardb, and Lars A. Buchhavec aDepartment of Astronomy, University of California, Berkeley, CA 94720; bInstitute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822; and cHarvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, MA 02138 Edited by Adam S. Burrows, Princeton University, Princeton, NJ, and accepted by the Editorial Board April 16, 2014 (received for review January 24, 2014) Small planets, 1–4× the size of Earth, are extremely common planets. The Doppler reflex velocity of an Earth-size planet − around Sun-like stars, and surprisingly so, as they are missing in orbiting at 0.3 AU is only 0.2 m s 1, difficult to detect with an − our solar system. Recent detections have yielded enough informa- observational precision of 1 m s 1. However, such Earth-size tion about this class of exoplanets to begin characterizing their planets show up as a ∼10-sigma dimming of the host star after occurrence rates, orbits, masses, densities, and internal structures. coadding the brightness measurements from each transit. The Kepler mission finds the smallest planets to be most common, The occurrence rate of Earth-size planets is a major goal of as 26% of Sun-like stars have small, 1–2 R⊕ planets with orbital exoplanet science. With three years of Kepler photometry in periods under 100 d, and 11% have 1–2 R⊕ planets that receive 1–4× hand, two groups worked to account for the detection biases in the incident stellar flux that warms our Earth. -
On the Polar Distances of the Greenwich Transit Circle
fi 1260-1263. l'he prominence, which iR due in many astronoiiiicsl re- ortlcr to restore this uniforiiiify , which is otiviously of the searches to the long and excellent series of the Greenwich iiiost esseritial iiriporhiicbe, 1 have rel'errctl all the otiser- mericliorial oliservations, gives to any changes of the instrri- vatioiis to the Circle reatlirigs. which corresporrtl to the Naclir nients, by means of which these ohservatioiis are procurecl, observations of the wire. It iiiight have heen tlcsirahle to a higher and more general importance, than they woulcl other- get rid, as much as pnssilile, of' pere~nalecpitions in the wise possess. Hence the interest, with which astrononicrs reading of iiiicroscope - iiiicronieters etc. hy iisiclg for each are wont to regRrtl the construction and cfhiency of any new observer his own Zenithpoints. A closer inspec:tiori sjiotv,, instrunient of superior pretensions, is greatly enhanced in however, that, owing to several ciiwes, this (:nurse is for the case of the powerful Greenwich Transit Circle, and the the past observations inipracticable. I have 'coiiserperitly asiral question, concerning the degree of correctness, which considered it best to adopt the same periods of uri;iltered the results of a new apparatus have attained, acquires addi- Zenithpoints, as have Iieerl used in the Greenwiclr rechictioris. tional claims to be answered. As I an1 not aware, that a The values of the corrections, which it was accordingly seces- strict determination of this point has yet been attempted, 1 sary to apply to the single ohservations, fluctuate I)ct\veeri shall here niake it the suhject of inquiry with reepect to -fO"45 and TO"71. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
10. Scientific Programme 10.1
10. SCIENTIFIC PROGRAMME 10.1. OVERVIEW (a) Invited Discourses Plenary Hall B 18:00-19:30 ID1 “The Zoo of Galaxies” Karen Masters, University of Portsmouth, UK Monday, 20 August ID2 “Supernovae, the Accelerating Cosmos, and Dark Energy” Brian Schmidt, ANU, Australia Wednesday, 22 August ID3 “The Herschel View of Star Formation” Philippe André, CEA Saclay, France Wednesday, 29 August ID4 “Past, Present and Future of Chinese Astronomy” Cheng Fang, Nanjing University, China Nanjing Thursday, 30 August (b) Plenary Symposium Review Talks Plenary Hall B (B) 8:30-10:00 Or Rooms 309A+B (3) IAUS 288 Astrophysics from Antarctica John Storey (3) Mon. 20 IAUS 289 The Cosmic Distance Scale: Past, Present and Future Wendy Freedman (3) Mon. 27 IAUS 290 Probing General Relativity using Accreting Black Holes Andy Fabian (B) Wed. 22 IAUS 291 Pulsars are Cool – seriously Scott Ransom (3) Thu. 23 Magnetars: neutron stars with magnetic storms Nanda Rea (3) Thu. 23 Probing Gravitation with Pulsars Michael Kremer (3) Thu. 23 IAUS 292 From Gas to Stars over Cosmic Time Mordacai-Mark Mac Low (B) Tue. 21 IAUS 293 The Kepler Mission: NASA’s ExoEarth Census Natalie Batalha (3) Tue. 28 IAUS 294 The Origin and Evolution of Cosmic Magnetism Bryan Gaensler (B) Wed. 29 IAUS 295 Black Holes in Galaxies John Kormendy (B) Thu. 30 (c) Symposia - Week 1 IAUS 288 Astrophysics from Antartica IAUS 290 Accretion on all scales IAUS 291 Neutron Stars and Pulsars IAUS 292 Molecular gas, Dust, and Star Formation in Galaxies (d) Symposia –Week 2 IAUS 289 Advancing the Physics of Cosmic -
Minor Body Science with the Nancy Grace Roman Space Telescope
! Minor Body Science with the Nancy Grace Roman Space Telescope Bryan J. Holler (STScI)*, Stefanie N. Milam (NASA/GSFC), James M. Bauer (U. Maryland), Jeffrey W. Kruk (NASA/GSFC), Charles Alcock (Harvard/CfA), Michele T. Bannister (U. of Canterbury), Gordon L. Bjoraker (NASA/GSFC), Dennis Bodewits (Auburn), Amanda S. Bosh (MIT), Marc W. Buie (SwRI), Tony L. Farnham (UMD), Nader Haghighipour (Hawaii/IfA), Paul S. Hardersen (Unaffiliated), Alan W. Harris (MoreData! Inc.), Christopher M. Hirata (Ohio State), Henry H. Hsieh (PSI, Academica Sinica), Michael S. P. Kelley (U. Maryland), Matthew M. Knight (USNA/U. Maryland), Emily A. Kramer (Caltech/JPL), Andrea Longobardo (INAF/IAPS), Conor A. Nixon (NASA/GSFC), Ernesto Palomba (INAF/IAPS), Silvia Protopapa (SwRI), Lynnae C. Quick (Smithsonian), Darin Ragozzine (BYU), Jason D. Rhodes (Caltech/JPL), Andy S. Rivkin (JHU/APL), Gal Sarid (SETI, Science Systems and Applications, Inc.), Amanda A. Sickafoose (SAAO, MIT), Cristina A. Thomas (NAU), David E. Trilling (NAU), Robert A. West (Caltech/JPL) *Contact information for primary author: Bryan J. Holler (STScI), [email protected], (667) 218-6404 Thematic areas: Ground- and space-based telescopes, Primitive bodies Solar system science with space telescopes There is a long history of solar system observations with space telescope facilities, from the Infrared Astronomical Satellite (IRAS) in the 1980s to present-day facilities such as the Hubble Space Telescope. Some of these facilities include a prominent solar system component as part of the original mission plan (e.g., WISE, JWST), some included this component late in mission design or even after primary operations begin (e.g., HST), and others never intended to support solar system observations until the proper opportunity arose (e.g., Kepler, Chandra). -
The Impact of Star Cluster Environments on Planet Formation
The Impact of Star Cluster Environments on Planet Formation Rhana Bethany Nicholson A thesis submitted in partial fulfilment of the requirements of Liverpool John Moores University for the degree of Doctor of Philosophy June 2019 i Declaration of Authorship I, Rhana Bethany Nicholson, declare that this thesis titled, “The Impact of Star Cluster Environments on Planet Formation” and the work presented in it are my own. I confirm that: • This work was done wholly or mainly while in candidature for a research degree at this University. • Where any part of this thesis has previously been submitted for a degree or any other qualification at this University or any other institution, this has been clearly stated. • Where I have consulted the published work of others, this is always clearly attributed. • Where I have quoted from the work of others, the source is always given. With the exception of such quotations, this thesis is entirely my own work. • I have acknowledged all main sources of help. • Where the thesis is based on work done by myself jointly with others, I have made clear exactly what was done by others and what I have contributed myself. Signed: Date: ii To Mum and Dad, for making me do Kumon. iii “For all the tenure of humans on Earth, the night sky has been a companion and an inspiration... At the very moment that humans discovered the scale of the Universe and found that their most unconstrained fancies were in fact dwarfed by the true dimensions of even the Milky Way Galaxy, they took steps that ensured that their descendants would be unable to see the stars at all...” - Carl Sagan, Contact iv Acknowledgements Firstly I must begin by thanking my supervisor, Richard Parker, without whom this thesis would most definitely not exist.