CIRCULAR No. 170 (FEBRUARY 2010)
Total Page：16
File Type：pdf, Size：1020Kb
Load more
Recommended publications
-
A Hot Subdwarf-White Dwarf Super-Chandrasekhar Candidate
A hot subdwarf–white dwarf super-Chandrasekhar candidate supernova Ia progenitor Ingrid Pelisoli1,2*, P. Neunteufel3, S. Geier1, T. Kupfer4,5, U. Heber6, A. Irrgang6, D. Schneider6, A. Bastian1, J. van Roestel7, V. Schaffenroth1, and B. N. Barlow8 1Institut fur¨ Physik und Astronomie, Universitat¨ Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, D-14476 Potsdam-Golm, Germany 2Department of Physics, University of Warwick, Coventry, CV4 7AL, UK 3Max Planck Institut fur¨ Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching bei Munchen¨ 4Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA 5Texas Tech University, Department of Physics & Astronomy, Box 41051, 79409, Lubbock, TX, USA 6Dr. Karl Remeis-Observatory & ECAP, Astronomical Institute, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Sternwartstr. 7, 96049 Bamberg, Germany 7Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 8Department of Physics and Astronomy, High Point University, High Point, NC 27268, USA *[email protected] ABSTRACT Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD 265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a hot subdwarf — a stripped core-helium burning star. -
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. -
CONSTELLATION VULPECULA, the (LITTLE) FOX Vulpecula Is a Faint Constellation in the Northern Sky
CONSTELLATION VULPECULA, THE (LITTLE) FOX Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the northern Summer Triangle (an asterism consisting of the bright stars Deneb in Cygnus (the Swan), Vega in Lyra (the Lyre) and Altair in Aquila (the Eagle). Vulpecula was introduced by the Polish astronomer Johannes Hevelius in the late 17th century. It is not associated with any figure in mythology. Hevelius originally named the constellation Vulpecula cum ansere, or Vulpecula et Anser, which means the little fox with the goose. The constellation was depicted as a fox holding a goose in its jaws. The stars were later separated to form two constellations, Anser and Vulpecula, and then merged back together into the present-day Vulpecula constellation. The goose was left out of the constellation’s name, but instead the brightest star, Alpha Vulpeculae, carries the name Anser. It is one of the seven constellations created by Hevelius. The fox and the goose shown as ‘Vulpec. & Anser’ on the Atlas Coelestis of John Flamsteed (1729). The Fox and Goose is a traditional pub name in Britain. STARS There are no stars brighter than 4th magnitude in this constellation. The brightest star is: Alpha Vulpeculae, a magnitude 4.44m red giant at a distance of 297 light-years. The star is an optical binary (separation of 413.7") that can be split using binoculars. The star also carries the traditional name Anser, which refers to the goose the little fox holds in its jaws. -
The Extragalactic Distance Scale
The Extragalactic Distance Scale Published in "Stellar astrophysics for the local group" : VIII Canary Islands Winter School of Astrophysics. Edited by A. Aparicio, A. Herrero, and F. Sanchez. Cambridge ; New York : Cambridge University Press, 1998 Calibration of the Extragalactic Distance Scale By BARRY F. MADORE1, WENDY L. FREEDMAN2 1NASA/IPAC Extragalactic Database, Infrared Processing & Analysis Center, California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA 91125, USA 2Observatories, Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena CA 91101, USA The calibration and use of Cepheids as primary distance indicators is reviewed in the context of the extragalactic distance scale. Comparison is made with the independently calibrated Population II distance scale and found to be consistent at the 10% level. The combined use of ground-based facilities and the Hubble Space Telescope now allow for the application of the Cepheid Period-Luminosity relation out to distances in excess of 20 Mpc. Calibration of secondary distance indicators and the direct determination of distances to galaxies in the field as well as in the Virgo and Fornax clusters allows for multiple paths to the determination of the absolute rate of the expansion of the Universe parameterized by the Hubble constant. At this point in the reduction and analysis of Key Project galaxies H0 = 72km/ sec/Mpc ± 2 (random) ± 12 [systematic]. Table of Contents INTRODUCTION TO THE LECTURES CEPHEIDS BRIEF SUMMARY OF THE OBSERVED PROPERTIES OF CEPHEID -
CH02 End of Chapter Answers Review Questions 1. According To
CH02 End of Chapter Answers Review Questions 1. According to Figure 2-7, the following wavelengths fall within the following ranges of the electromagnetic spectrum: a. 2.6 m – Infrared b. 34 m – Radio c. 0.54 nm – X-rays d. 0.0032 nm – Gamma rays e. 0.620 m – Visible f. 310 nm – Ultraviolet g. 0.012 m – This lies right near the border between microwave and radio waves. Since the figure is not accurate to two decimal places, it is not possible to determine within which wavelength regime this falls. 2. Since radio waves are a form of electromagnetic radiation, they travel at the speed of light. The wavelength and frequency of any wave is related by the formula: f = c, where c is equal to the speed of light, or 3 × 108 m/s. Using this formula, and knowing the values for both c and f (880.65 MHz, or 8.8065 × 108 Hz), we can solve for the wavelength: = 3 × 108 m/s / 8.8065 x 108 Hz = 0.341 meters. 3. According to the Stefan-Boltzmann law, hotter objects radiate more intensely than cooler objects. According to Wien’s law, that energy is not radiated uniformly at all wavelengths, but mostly at a wavelength that is inversely proportional to the temperature of the object. As a hot, glowing object becomes hotter, it radiates more intensely at all wavelengths, becoming brighter, and shifts the peak wavelength (at which it radiates the most energy) to shorter wavelengths, becoming bluer. 4. According to the Stefan-Boltzmann law, the intensity of a blackbody object is related to the temperature of an object to the fourth power. -
Jason A. Dittmann 51 Pegasi B Postdoctoral Fellow
Jason A. Dittmann 51 Pegasi b Postdoctoral Fellow Contact Massachusetts Institute of Technology MIT Kavli Institute: 37-438f 617-258-5928 (office) 70 Vassar St. 520-820-0928 (cell) Cambridge, MA 02139 [email protected] Education Harvard University, Cambridge, MA PhD, Astronomy and Astrophysics, May 2016 Advisor: David Charbonneau, PhD • University of Arizona, Tucson, AZ BS, Astronomy, Physics, May 2010 Advisor: Laird Close, PhD • Recent 51 Pegasi b Postdoctoral Fellow July 2017 – Present Research Earth and Planetary Science Department, MIT Positions Faculty Contact: Sara Seager Postdoctoral Researcher Feb 2017 – June 2017 Kavli Institute, MIT Supervisor: Sarah Ballard Postdoctoral Researcher July 2016 – Jan 2017 Center for Astrophysics, Harvard University Supervisor: David Charbonneau Research Assistant Sep 2010 – May 2016 Center for Astrophysics, Harvard University Advisors: David Charbonneau Publication 16 first and second authored publications Summary 22 additional co-authored publications 1 first-authored publication in Nature 1 co-authored publication in Nature Selected 51 Pegasi b Postdoctoral Fellowship 2017 – Present Awards and Pierce Fellowship 2010 – 2013 Honors Certificate of Distinction in Teaching 2012 Best Project Award, Physics Ugrd. Research Symp. 2009 Best Undergraduate Research (Steward Observatory) 2009 – 2010 Grants Principal Investigator, Hubble Space Telescope 2017, 10 orbits Awarded “Initial Reconaissance of a Transiting Rocky (maximum award) Planet in a Nearby M-Dwarf’s Habitable Zone” Principal Investigator, -
Astronomical Detection of a Radioactive Molecule 26Alf in a Remnant of an Ancient Explosion
Astronomical detection of a radioactive molecule 26AlF in a remnant of an ancient explosion Tomasz Kamiński1*, Romuald Tylenda2, Karl M. Menten3, Amanda Karakas4, 5 6 5 6 1 Jan Martin Winters , Alexander A. Breier , Ka Tat Wong , Thomas F. Giesen , Nimesh A. Patel 1Harvard-Smithsonian Center for Astrophysics, MS 78, 60 Garden Street, Cambridge, MA 02138, USA 2Department for Astrophysics, N. Copernicus Astronomical Center, Rabiańska 8, 87-100, Toruń, Poland 3Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany 4Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, VIC 3800, Australia 5IRAM, 300 rue de la Piscine, Domaine Universitaire de Grenoble, 38406, St. Martin d’Héres, France 6Laborastrophysik, Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, Kassel, Germany *Correspondence to: [email protected] Decades ago, γ-ray observatories identified diffuse Galactic emission at 1.809 MeV (1-3) originating from β+ decays of an isotope of aluminium, 26Al, that has a mean-life time of 1.04 million years (4). Objects responsible for the production of this radioactive isotope have never been directly identified, owing to insufficient angular resolutions and sensitivities of the γ-ray observatories. Here, we report observations of millimetre-wave rotational lines of the isotopologue of aluminium monofluoride that contains the radioactive isotope (26AlF). The emission is observed toward CK Vul which is thought to be a remnant of a stellar merger (5-7). Our constraints on the production of 26Al combined with the estimates on the merger rate make it unlikely that objects similar to CK Vul are major producers of Galactic 26Al. -
GEORGE HERBIG and Early Stellar Evolution
GEORGE HERBIG and Early Stellar Evolution Bo Reipurth Institute for Astronomy Special Publications No. 1 George Herbig in 1960 —————————————————————– GEORGE HERBIG and Early Stellar Evolution —————————————————————– Bo Reipurth Institute for Astronomy University of Hawaii at Manoa 640 North Aohoku Place Hilo, HI 96720 USA . Dedicated to Hannelore Herbig c 2016 by Bo Reipurth Version 1.0 – April 19, 2016 Cover Image: The HH 24 complex in the Lynds 1630 cloud in Orion was discov- ered by Herbig and Kuhi in 1963. This near-infrared HST image shows several collimated Herbig-Haro jets emanating from an embedded multiple system of T Tauri stars. Courtesy Space Telescope Science Institute. This book can be referenced as follows: Reipurth, B. 2016, http://ifa.hawaii.edu/SP1 i FOREWORD I first learned about George Herbig’s work when I was a teenager. I grew up in Denmark in the 1950s, a time when Europe was healing the wounds after the ravages of the Second World War. Already at the age of 7 I had fallen in love with astronomy, but information was very hard to come by in those days, so I scraped together what I could, mainly relying on the local library. At some point I was introduced to the magazine Sky and Telescope, and soon invested my pocket money in a subscription. Every month I would sit at our dining room table with a dictionary and work my way through the latest issue. In one issue I read about Herbig-Haro objects, and I was completely mesmerized that these objects could be signposts of the formation of stars, and I dreamt about some day being able to contribute to this field of study. -
Analysis of New High-Precision Transit Light Curves of WASP-10 B: Starspot Occultations, Small Planetary Radius, and High Metallicity ,
A&A 535, A7 (2011) Astronomy DOI: 10.1051/0004-6361/201117127 & c ESO 2011 Astrophysics Analysis of new high-precision transit light curves of WASP-10 b: starspot occultations, small planetary radius, and high metallicity, G. Maciejewski1,2, St. Raetz2, N. Nettelmann3, M. Seeliger2,C.Adam2,G.Nowak1, and R. Neuhäuser2 1 Torun´ Centre for Astronomy, Nicolaus Copernicus University, Gagarina 11, 87100 Torun,´ Poland e-mail: [email protected] 2 Astrophysikalisches Institut und Universitäts-Sternwarte, Schillergässchen 2–3, 07745 Jena, Germany 3 Institut für Physik, Universität Rostock, 18051 Rostock, Germany Received 22 April 2011 / Accepted 5 September 2011 ABSTRACT Context. The WASP-10 planetary system is intriguing because different values of radius have been reported for its transiting exoplanet. The host star exhibits activity in terms of photometric variability, which is caused by the rotational modulation of the spots. Moreover, a periodic modulation has been discovered in transit timing of WASP-10 b, which could be a sign of an additional body perturbing the orbital motion of the transiting planet. Aims. We attempt to refine the physical parameters of the system, in particular the planetary radius, which is crucial for studying the internal structure of the transiting planet. We also determine new mid-transit times to confirm or refute observed anomalies in transit timing. Methods. We acquired high-precision light curves for four transits of WASP-10 b in 2010. Assuming various limb-darkening laws, we generated best-fit models and redetermined parameters of the system. The prayer-bead method and Monte Carlo simulations were used to derive error estimates. -
WASP-80B: a Gas Giant Transiting a Cool Dwarf⋆⋆⋆
A&A 551, A80 (2013) Astronomy DOI: 10.1051/0004-6361/201220900 & c ESO 2013 Astrophysics WASP-80b: a gas giant transiting a cool dwarf, A. H. M. J. Triaud1,D.R.Anderson2, A. Collier Cameron3,A.P.Doyle2,A.Fumel4, M. Gillon4, C. Hellier2, E. Jehin4, M. Lendl1,C.Lovis1,P.F.L.Maxted2,F.Pepe1, D. Pollacco5,D.Queloz1, D. Ségransan1,B.Smalley2, A. M. S. Smith2,6,S.Udry1,R.G.West7, and P. J. Wheatley5 1 Observatoire Astronomique de l’Université de Genève, Chemin des Maillettes 51, 1290 Sauverny, Switzerland e-mail: [email protected] 2 Astrophysics Group, Keele University, Staffordshire, ST55BG, UK 3 SUPA, School of Physics & Astronomy, University of St. Andrews, North Haugh, KY16 9SS, St. Andrews, Fife, Scotland, UK 4 Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août, 17, Bat. B5C, Liège 1, Belgium 5 Department of Physics, University of Warwick, Coventry CV4 7AL, UK 6 N. Copernicus Astronomical Centre, Polish Academy of Sciences, Bartycka 18, 00-716 Warsaw, Poland 7 Department of Physics and Astronomy, University of Leicester, Leicester, LE17RH, UK Received 13 December 2012 / Accepted 9 January 2013 ABSTRACT We report the discovery of a planet transiting the star WASP-80 (1SWASP J201240.26-020838.2; 2MASS J20124017-0208391; TYC 5165-481-1; BPM 80815; V = 11.9, K = 8.4). Our analysis shows this is a 0.55 ± 0.04 Mjup,0.95 ± 0.03 Rjup gas giant on a circular 3.07 day orbit around a star with a spectral type between K7V and M0V. -
Binocular Challenges
This page intentionally left blank Cosmic Challenge Listing more than 500 sky targets, both near and far, in 187 challenges, this observing guide will test novice astronomers and advanced veterans alike. Its unique mix of Solar System and deep-sky targets will have observers hunting for the Apollo lunar landing sites, searching for satellites orbiting the outermost planets, and exploring hundreds of star clusters, nebulae, distant galaxies, and quasars. Each target object is accompanied by a rating indicating how difficult the object is to find, an in-depth visual description, an illustration showing how the object realistically looks, and a detailed finder chart to help you find each challenge quickly and effectively. The guide introduces objects often overlooked in other observing guides and features targets visible in a variety of conditions, from the inner city to the dark countryside. Challenges are provided for viewing by the naked eye, through binoculars, to the largest backyard telescopes. Philip S. Harrington is the author of eight previous books for the amateur astronomer, including Touring the Universe through Binoculars, Star Ware, and Star Watch. He is also a contributing editor for Astronomy magazine, where he has authored the magazine’s monthly “Binocular Universe” column and “Phil Harrington’s Challenge Objects,” a quarterly online column on Astronomy.com. He is an Adjunct Professor at Dowling College and Suffolk County Community College, New York, where he teaches courses in stellar and planetary astronomy. Cosmic Challenge The Ultimate Observing List for Amateurs PHILIP S. HARRINGTON CAMBRIDGE UNIVERSITY PRESS Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, Sao˜ Paulo, Delhi, Dubai, Tokyo, Mexico City Cambridge University Press The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America by Cambridge University Press, New York www.cambridge.org Information on this title: www.cambridge.org/9780521899369 C P. -
On the Atmospheres of the Smallest Gas Exoplanets
On the Atmospheres of the Smallest Gas Exoplanets by Erin M. May A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Astronomoy and Astrophysics) in The University of Michigan 2019 Doctoral Committee: Assistant Professor Emily Rasucher, Chair Professor Fred Adams Professor Michael Meyer Professor John Monnier Erin M. May [email protected] ORCID iD: 0000-0002-2739-1465 c Erin M. May 2019 For my cat. May she learn to love me at least as much as I love this dissertation. ii ACKNOWLEDGEMENTS \I don't have emotions. And sometimes that makes me very sad." { Bender, the Robot I've never been much for emotions, but if it's a required component of this dissertation... First, thank you to Alex. I may have been a pain to deal with during parts of this process, but we both made it through. Thank you to Li'l B who taught me that not everything that's perfect is perfect for you and that love isn't unconditional. Especially from a cat. Thank you to the humans in the department who were there for me along the way. In particular, Emily, who was the advisor I needed but didn't deserve. To Renee for confirming that there's no such thing as too many macarons on a Friday, and for the constant commiserating throughout the past year. And because this human requested this acknowledgement, to Adi for saving me that one time from that one thing. Thank you to the regular GB@3 crew, even those who showed up late or barely at all.