May 2019 BRAS Newsletter
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Linking Stars, Planets and Debris Through Herschel Observations of Radial Velocity Exoplanet Host Stars
Linking stars, planets and debris through Herschel observations of radial velocity exoplanet host stars Jonathan P. Marshall Universidad Autónoma de Madrid Introduction • Herschel observed 104 radial velocity exoplanet host stars, of which 30 also had detectable circumstellar discs (DEBRIS, DUNES, GT and SKARPS) • Given that we expect planets to form from the agglomeration of planetesimals, there should be some link between the two • Previous work with Spitzer identified no correlation between planets and debris (Moro-martin et al. 2007, Bryden et al. 2009) • Observational signatures of planets may be visible in the spatial distribution of dust discs around other stars Imaging exoplanets • We find exoplanets in systems with debris discs (Marois et al. 2008; Bonnefoy et al. 2011; Rameau et al. 2013) Multi-component discs • HIP 17439’s debris disc is potentially the result of two cold dust belts Ertel et al. 2014 Schueppler et al., subm. Dynamical interactions • e.g. Eta Corvi’s Spitzer IRS spectrum shows evidence for KBO material in inner system Matthews et al. 2010 Lisse et al. 2012 Perturbation • Stars hosting exoplanets with low orbital eccentricities show a weak tendency to have brighter discs • Planets with lower eorb are less disruptive to parent bodies in debris belts Maldonado et al. 2012 Eccentric discs • e.g. HIP 15371 • Asymmetric structure proposed to be the result of dynamical perturbation by a planetary companion . Similar evidence seen in other discs (in sub-mm) tends to be weak, potentially result of low s/n observation . Not necessarily a planet, as remnant gas could affect dust Faramaz et al. 2014 Coplanarity • Inclination of star, i*, and disc, id • Debris discs are generally seen to lie along the equatorial plane of the host star • Few exceptions, e.g. -
Mathématiques Et Espace
Atelier disciplinaire AD 5 Mathématiques et Espace Anne-Cécile DHERS, Education Nationale (mathématiques) Peggy THILLET, Education Nationale (mathématiques) Yann BARSAMIAN, Education Nationale (mathématiques) Olivier BONNETON, Sciences - U (mathématiques) Cahier d'activités Activité 1 : L'HORIZON TERRESTRE ET SPATIAL Activité 2 : DENOMBREMENT D'ETOILES DANS LE CIEL ET L'UNIVERS Activité 3 : D'HIPPARCOS A BENFORD Activité 4 : OBSERVATION STATISTIQUE DES CRATERES LUNAIRES Activité 5 : DIAMETRE DES CRATERES D'IMPACT Activité 6 : LOI DE TITIUS-BODE Activité 7 : MODELISER UNE CONSTELLATION EN 3D Crédits photo : NASA / CNES L'HORIZON TERRESTRE ET SPATIAL (3 ème / 2 nde ) __________________________________________________ OBJECTIF : Détermination de la ligne d'horizon à une altitude donnée. COMPETENCES : ● Utilisation du théorème de Pythagore ● Utilisation de Google Earth pour évaluer des distances à vol d'oiseau ● Recherche personnelle de données REALISATION : Il s'agit ici de mettre en application le théorème de Pythagore mais avec une vision terrestre dans un premier temps suite à un questionnement de l'élève puis dans un second temps de réutiliser la même démarche dans le cadre spatial de la visibilité d'un satellite. Fiche élève ____________________________________________________________________________ 1. Victor Hugo a écrit dans Les Châtiments : "Les horizons aux horizons succèdent […] : on avance toujours, on n’arrive jamais ". Face à la mer, vous voyez l'horizon à perte de vue. Mais "est-ce loin, l'horizon ?". D'après toi, jusqu'à quelle distance peux-tu voir si le temps est clair ? Réponse 1 : " Sans instrument, je peux voir jusqu'à .................. km " Réponse 2 : " Avec une paire de jumelles, je peux voir jusqu'à ............... km " 2. Nous allons maintenant calculer à l'aide du théorème de Pythagore la ligne d'horizon pour une hauteur H donnée. -
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. -
Catalog of Nearby Exoplanets
Catalog of Nearby Exoplanets1 R. P. Butler2, J. T. Wright3, G. W. Marcy3,4, D. A Fischer3,4, S. S. Vogt5, C. G. Tinney6, H. R. A. Jones7, B. D. Carter8, J. A. Johnson3, C. McCarthy2,4, A. J. Penny9,10 ABSTRACT We present a catalog of nearby exoplanets. It contains the 172 known low- mass companions with orbits established through radial velocity and transit mea- surements around stars within 200 pc. We include 5 previously unpublished exo- planets orbiting the stars HD 11964, HD 66428, HD 99109, HD 107148, and HD 164922. We update orbits for 90 additional exoplanets including many whose orbits have not been revised since their announcement, and include radial ve- locity time series from the Lick, Keck, and Anglo-Australian Observatory planet searches. Both these new and previously published velocities are more precise here due to improvements in our data reduction pipeline, which we applied to archival spectra. We present a brief summary of the global properties of the known exoplanets, including their distributions of orbital semimajor axis, mini- mum mass, and orbital eccentricity. Subject headings: catalogs — stars: exoplanets — techniques: radial velocities 1Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the Uni- versity of California and the California Institute of Technology. The Keck Observatory was made possible by the generous financial support of the W. M. Keck Foundation. arXiv:astro-ph/0607493v1 21 Jul 2006 2Department of Terrestrial Magnetism, Carnegie Institute of Washington, 5241 Broad Branch Road NW, Washington, DC 20015-1305 3Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720-3411 4Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 5UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 6Anglo-Australian Observatory, PO Box 296, Epping. -
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. -
Arxiv:0809.1275V2
How eccentric orbital solutions can hide planetary systems in 2:1 resonant orbits Guillem Anglada-Escud´e1, Mercedes L´opez-Morales1,2, John E. Chambers1 [email protected], [email protected], [email protected] ABSTRACT The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect ex- oplanets. If several planets are present, their signals will appear combined in the radial motion of the star, leading to potential misinterpretations of the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal of a sin- gle planet in an eccentric orbit. We quantify the implications of this statistical degeneracy for a representative sample of the reported single exoplanets with available datasets, finding that 1) around 35% percent of the published eccentric one-planet solutions are statistically indistinguishible from planetary systems in 2:1 orbital resonance, 2) another 40% cannot be statistically distinguished from a circular orbital solution and 3) planets with masses comparable to Earth could be hidden in known orbital solutions of eccentric super-Earths and Neptune mass planets. Subject headings: Exoplanets – Orbital dynamics – Planet detection – Doppler method arXiv:0809.1275v2 [astro-ph] 25 Nov 2009 Introduction Most of the +300 exoplanets found to date have been discovered using the Doppler tech- nique, which measures the reflex motion of the host star induced by the planets (Mayor & Queloz 1995; Marcy & Butler 1996). The diverse characteristics of these exoplanets are somewhat surprising. Many of them are similar in mass to Jupiter, but orbit much closer to their 1Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Rd. -
Virgo the Virgin
Virgo the Virgin Virgo is one of the constellations of the zodiac, the group tion Virgo itself. There is also the connection here with of 12 constellations that lies on the ecliptic plane defined “The Scales of Justice” and the sign Libra which lies next by the planets orbital orientation around the Sun. Virgo is to Virgo in the Zodiac. The study of astronomy had a one of the original 48 constellations charted by Ptolemy. practical “time keeping” aspect in the cultures of ancient It is the largest constellation of the Zodiac and the sec- history and as the stars of Virgo appeared before sunrise ond - largest constellation after Hydra. Virgo is bordered by late in the northern summer, many cultures linked this the constellations of Bootes, Coma Berenices, Leo, Crater, asterism with crops, harvest and fecundity. Corvus, Hydra, Libra and Serpens Caput. The constella- tion of Virgo is highly populated with galaxies and there Virgo is usually depicted with angel - like wings, with an are several galaxy clusters located within its boundaries, ear of wheat in her left hand, marked by the bright star each of which is home to hundreds or even thousands of Spica, which is Latin for “ear of grain”, and a tall blade of galaxies. The accepted abbreviation when enumerating grass, or a palm frond, in her right hand. Spica will be objects within the constellation is Vir, the genitive form is important for us in navigating Virgo in the modern night Virginis and meteor showers that appear to originate from sky. Spica was most likely the star that helped the Greek Virgo are called Virginids. -
Telescope to Seek Dust Where Other Earths May Lie 22 January 2015, by Whitney Clavin
Telescope to seek dust where other Earths may lie 22 January 2015, by Whitney Clavin The new instrument, based at the Large Binocular Telescope Observatory at the top of Mount Graham in southeastern Arizona, will obtain the best infrared images yet of dust permeating a star's habitable zone, the region around the star where water—an essential ingredient for life as we know it—could pool on a planet. Earth sits comfortably within our sun's habitable zone, hence its glistening surface of oceans. Scientists want to take pictures of exo-Earths and break up their light into a rainbow of colors. This color information is displayed in plots, called The Large Binocular Telescope Interferometer (LBTI) spectra, which reveal chemical clues about whether instrument set its eyes on a dusty star system called Eta a planet could sustain life. But dust—which comes Corvi, depicted here in this artist's concept. Recent from colliding asteroids and evaporating collisions between comets and rocky bodies within the comets—can outshine the feeble light of a planet, star system are thought to have generated the surplus of making this task difficult. dust. Credit: Large Binocular Telescope Observatory "Imagine trying to view a firefly buzzing around a lighthouse in Canada from Los Angeles," said Denis Defrère of the University of Arizona, lead The NASA-funded Large Binocular Telescope author of the new study that appears in the Jan. 14 Interferometer, or LBTI, has completed its first issue of the Astrophysical Journal. "Now imagine study of dust in the "habitable zone" around a star, that fog is in the way. -
May 2013 BRAS Newsletter
www.brastro.org May 2013 What's in this issue: PRESIDENT'S MESSAGE .............................................................................................................................. 2 NOTES FROM THE VICE PRESIDENT ........................................................................................................... 3 MESSAGE FROM THE HRPO ...................................................................................................................... 4 OBSERVING NOTES ..................................................................................................................................... 5 DEEP SKY OBJECTS ................................................................................................................................... 6 MAY ASTRONOMICAL EVENTS .................................................................................................................... 7 TREASURER’S NOTES ................................................................................................................................. 8 PREVIOUS MEETING MINUTES .................................................................................................................... 9 IMPORTANT NOTE: This month's meeting will be held on Saturday, May 18th at LIGO. PRESIDENT'S MESSAGE Hi Everyone, April was quite a busy month and the busiest day was International Astronomy Day. As you may have heard, we had the highest attendance at our Astronomy Day festivities at the HRPO ever. Approximately 770 people attended this year -
Debris Disks: the First 30 Years Where Will Herschel Take Us?
With thanks to M. Wyatt, P. Kalas, L. Churcher, G. Duchene, B. Sibthorpe, A. Roberge Debris Disks: the first 30 years Where will Herschel take us? Brenda Matthews Herzberg Institute of Astrophysics & University of Victoria Outline • Debris disk: definition and discovery • Incidence and evolution • Characterizing debris disks • Disks around low-mass stars (AU Mic) • Planetary connection • Herschel surveys “Debris” Disks • Debris disks are produced from the remnants of the planet formation process • Second generation dust is produced through collisional processes • The debris disk can include – Planetesimal population (though not directly observable) – Dust produced (detectable from optical centimetre) • Dust may lie in belts at various radii from the star Solar System Debris Disk Kuiper Belt Asteroid Belt Debris Disk Snapshot: Zodiacal Light Photo: Stefan Binnewies "The light at its brightest was considerably fainter than the brighter" portions of the milky way... The outline generally appeared of a " parabolic or probably elliptical form, and it would seem excentric" as regards the sun, and also inclined, though but slightly to the ecliptic."" "-- Captain Jacob 1859 Discovery: Vega Phenomenon IRAS finds excess around 20% of main sequence stars (Rhee et al. 2007) Backman & Paresce 1993" "The Big Three"" The discovery of excess emission from main sequence stars at IRAS wavelengths (Aumann et al. 1984). Circumstellar Dust Disks Smith & Terrile 1984 Beta Pic was the Rosetta Stone Debris Disk for 15 years >300 refereed papers Dust must be second generation •! Debris disks cannot be the remnants of the protoplanetary disks found around pre-main sequence stars (Backman & Paresce 1993): –! The stars are old (e.g., up to 100s of Myr, even Gyr) –! The dust is small (< 100 micron) (Harper et al. -
The Multidimensional Guide to Science Fiction and Fantasy of the Twentieth Century, Volume 1
THE MULTIDIMENSIONAL GUIDE TO SCIENCE FICTION AND FANTASY OF THE TWENTIETH CENTURY, VOLUME 1 EDITED BY NAT TILANDER 2 Copyright © 2010 by Nathaniel Garret Tilander All rights reserved. No part of this book may be reproduced, stored, or transmitted by any means—whether auditory, graphic, mechanical, or electronic—without written permission of both publisher and author, except in the case of brief excerpts used in critical articles and reviews. Unauthorized reproduction of any part of this work is illegal and is punishable by law. Cover art from the novella Last Enemy by H. Beam Piper, first published in the August 1950 issue of Astounding Science Fiction, and illustrated by Miller. Image downloaded from the ―zorger.com‖ website which states that the image is licensed under a Creative Commons Public Domain License. Additional copyrighted materials incorporated in this book are as follows: Copyright © 1949-1951 by L. Sprague de Camp. These articles originally appeared in Analog Science Fiction. Copyright © 1951-1979 by P. Schuyler Miller. These articles originally appeared in Analog Science Fiction. Copyright © 1975-1979 by Lester Del Rey. These articles originally appeared in Analog Science Fiction. Copyright © 1978-1981 by Spider Robinson. These articles originally appeared in Analog Science Fiction. Copyright © 1979-1999 by Tom Easton. These articles originally appeared in Analog Science Fiction. Copyright © 1950-1954 by J. Francis McComas. These articles originally appeared in Fantasy and Science Fiction. Copyright © 1950-1959 by Anthony Boucher. These articles originally appeared in Fantasy and Science Fiction. Copyright © 1959-1960 by Damon Knight. These articles originally appeared in Fantasy and Science Fiction. -
The Moon Greets the Planets in the November Dawn 4 November 2015, by David Dickinson
The moon greets the planets in the November dawn 4 November 2015, by David Dickinson Watch the scene shift, as the moon joins the dance this weekend. The mornings of Friday, October 6th and Saturday, October 7th are key, as the moon passes just two degrees from the Jupiter and Mars pair and just over one degree from Venus worldwide. Similar close pairings of the moon and Venus adorn many national flags, possibly inspired by a close grouping of Venus and the moon witnessed by skywatchers of yore. Saturday November 7th is also a fine time to try your hand at seeing Venus in the daytime, using the nearby crescent moon as a guide. The moon will be only four days from New, and the pair will be 46 degrees west of the sun, an optimal situation as A tri-planetary grouping from the morning of October Venus just passed greatest western elongation 31st. Credit: Joseph Brimacombe 46.4 degrees west of the sun on October 26th. So did this past weekend's shift back to Standard Time for most of North America throw you for a loop? Coming the day after Halloween, 2015 was the earliest we can now shift back off Daylight Saving Time. Sunday won't fall on November 1st again until 2020. Expect evenings get darker sooner for northern hemisphere residents, while the planetary action remains in the dawn sky. Though Mercury has exited the morning twilight stage, the planets Jupiter, Venus and Mars continue to put on a fine show, joined by the waning crescent moon later this week.