Spectrally Resolved Detection of Sodium in the Atmosphere of HD 189733B with the HARPS Spectrograph? A
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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. -
The Near-Infrared Multi-Band Ultraprecise Spectroimager for SOFIA
NIMBUS: The Near-Infrared Multi-Band Ultraprecise Spectroimager for SOFIA Michael W. McElwaina, Avi Mandella, Bruce Woodgatea, David S. Spiegelb, Nikku Madhusudhanc, Edward Amatuccia, Cullen Blaked, Jason Budinoffa, Adam Burgassere, Adam Burrowsd, Mark Clampina, Charlie Conroyf, L. Drake Demingg, Edward Dunhamh, Roger Foltza, Qian Gonga, Heather Knutsoni, Theodore Muencha, Ruth Murray-Clayf, Hume Peabodya, Bernard Rauschera, Stephen A. Rineharta, Geronimo Villanuevaj aNASA Goddard Space Flight Center, Greenbelt, MD, USA; bInstitute for Advanced Study, Princeton, NJ, USA; cYale University, New Haven, CT, USA; dPrinceton University, Princeton, NJ, USA; eUniversity of California, San Diego, La Jolla, CA, USA; fHarvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA; gUniversity of Maryland, College Park, MD, USA; hLowell Observatory, Flagstaff, AZ, USA; iCalifornia Institute of Technology, Pasadena, CA; jCatholic University of America, Washington, DC, USA. ABSTRACT We present a new and innovative near-infrared multi-band ultraprecise spectroimager (NIMBUS) for SOFIA. This design is capable of characterizing a large sample of extrasolar planet atmospheres by measuring elemental and molecular abundances during primary transit and occultation. This wide-field spectroimager would also provide new insights into Trans-Neptunian Objects (TNO), Solar System occultations, brown dwarf atmospheres, carbon chemistry in globular clusters, chemical gradients in nearby galaxies, and galaxy photometric redshifts. NIMBUS would be the premier ultraprecise -
Stellar Magnetic Activity – Star-Planet Interactions
EPJ Web of Conferences 101, 005 02 (2015) DOI: 10.1051/epjconf/2015101005 02 C Owned by the authors, published by EDP Sciences, 2015 Stellar magnetic activity – Star-Planet Interactions Poppenhaeger, K.1,2,a 1 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambrigde, MA 02138, USA 2 NASA Sagan Fellow Abstract. Stellar magnetic activity is an important factor in the formation and evolution of exoplanets. Magnetic phenomena like stellar flares, coronal mass ejections, and high- energy emission affect the exoplanetary atmosphere and its mass loss over time. One major question is whether the magnetic evolution of exoplanet host stars is the same as for stars without planets; tidal and magnetic interactions of a star and its close-in planets may play a role in this. Stellar magnetic activity also shapes our ability to detect exoplanets with different methods in the first place, and therefore we need to understand it properly to derive an accurate estimate of the existing exoplanet population. I will review recent theoretical and observational results, as well as outline some avenues for future progress. 1 Introduction Stellar magnetic activity is an ubiquitous phenomenon in cool stars. These stars operate a magnetic dynamo that is fueled by stellar rotation and produces highly structured magnetic fields; in the case of stars with a radiative core and a convective outer envelope (spectral type mid-F to early-M), this is an αΩ dynamo, while fully convective stars (mid-M and later) operate a different kind of dynamo, possibly a turbulent or α2 dynamo. These magnetic fields manifest themselves observationally in a variety of phenomena. -
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. -
A Search for Variability and Transit Signatures In
A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA A thesis presented to the faculty of 3 ^ San Francisco State University Zo\% In partial fulfilment of W* The Requirements for The Degree Master of Science In Physics: Astronomy by Badrinath Thirumalachari San JVancisco, California December 2018 Copyright by Badrinath Thirumalachari 2018 CERTIFICATION OF APPROVAL I certify that I have read A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA by Badrinath Thirumalachari and that in my opinion this work meets the criteria for approving a thesis submitted in partial fulfillment of the requirements for the degree: Master of Science in Physics: Astronomy at San Francisco State University. fov- Dr. Stephen Kane, Ph.D. Astrophysics Associate Professor of Planetary Astrophysics Dr. Uo&eph Barranco, Ph.D. .%trtJphysics Chairfe Associate Professor of Physics K + A Q , L a . Dr. Ron Marzke, Ph.D. Astronomy Assoc. Dean of College of Science & Engineering A SEARCH FOR VARIABILITY AND TRANSIT SIGNATURES IN HIPPARCOS PHOTOMETRIC DATA Badrinath Thirumalachari San Francisco State University 2018 The study and characterization of exoplanets has picked up pace rapidly over the past few decades with the invention of newer techniques and instruments. Detecting transits in stellar photometric data around stars already known to harbor exoplanets is crucial for exoplanet characterization. Due to these advancements we now have oceans of data and coming up with an automated way of performing exoplanet characterization is a challenge. In this thesis I describe one such method to search for transits in Hipparcos dataset containing photometric data for over 118000 stars. The radial velocity method has discovered a lot of planets around bright host stars and a follow up transit detection will give us the density of the exoplanet. -
View of the Interior Structure
UNIVERSITY OF CINCINNATI Date: 17-Sep-2010 I, Benjamin Frank Bubnick , hereby submit this original work as part of the requirements for the degree of: Master of Science in Physics It is entitled: Massive Stellar Clusters in the Disk of the Milky Way Galaxy Student Signature: Benjamin Frank Bubnick This work and its defense approved by: Committee Chair: Margaret Hanson, PhD Margaret Hanson, PhD 10/4/2010 1,102 Massive Stellar Clusters in the Disk of the Milky Way Galaxy A Thesis submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of Master of Science in the Department of Physics of the College of Arts and Sciences 2010 by Benjamin Bubnick Committee Chair: Margaret Hanson ABSTRACT Title of thesis: Massive Stellar Clusters in the Disk Of the Milky Way Galaxy Benjamin Bubnick, Master of Science, 2010 Thesis directed by: Professor Margaret Hanson Department of Physics This thesis outlines successful efforts for identifying and characterizing the stellar content of two Galactic disk star clusters using near-infrared observations. Astronomers have a great wealth of knowledge about globular clusters. They are easy to see as most lie outside the plane of the galaxy in the halo. Extinction is low, the stellar population is dense in the cluster, and they are fairly common. However, in the plane of the galaxy, relatively little is known of the open cluster population. Galactic disk open clusters, such as the two discussed in this thesis, are hidden behind gas, dust, and projected against a multitude of field stars. -
Transit Polarimetry of Exoplanetary System HD 189733
Transit Polarimetry of Exoplanetary System HD 189733 N.M. Kostogryz1,3, S.V. Berdyugina1,2, T.M. Yakobchuk3 1Kiepenheuer Institut f¨urSonnenphysik, Sch¨oneckstr. 6, 79104 Freiburg, Germany 2NASA Astrobiology Institute, Institute for Astronomy, University of Hawaii, USA 3Main Astronomical Observatory of NAS of Ukraine, Zabolotnoho str. 27, 03680 Kyiv, Ukraine Abstract. We present and discuss a polarimetric effect caused by a planet transiting the stellar disk thus breaking the symmetry of the light distribution and resulting in linear polarization of the partially eclipsed star. Estimates of this effect for transiting planets have been made only recently. In particular, we demonstrate that the maximum polarization during transits depends strongly on the centre-to-limb variation of the linear polarization of the host star. However, observational and theoretical studies of the limb polarization have largely concentrated on the Sun. Here we solve the radiative transfer problem for polarized light and calculate the centre-to-limb polarization for one of the brightest transiting planet host HD 189733 taking into account various opacities. Using that we simulate the transit effect and estimate the variations of the flux and the linear polarization for HD 189733 during the event. As the spots on the stellar disk also break the limb polarization symmetry we simulate the flux and polarization variation due to the spots on the stellar disk. 1. Introduction HD 189733 is currently the brightest (mV = 7.67mag) star known to harbour a transiting exoplanet (Bouchy et al. 2005). This, along with the short period (2.2 days) and large ratio of planet-to-star radii (Rpl/R⋆ ≈ 0.15), makes it very suitable for different types of observations including polarimetry (Berdyugina et al. -
A Method of Correcting Near-Infrared Spectra for Telluric Absorption1
Publications of the Astronomical Society of the Pacific, 115:389–409, 2003 March ᭧ 2003. The Astronomical Society of the Pacific. All rights reserved. Printed in U.S.A. A Method of Correcting Near-Infrared Spectra for Telluric Absorption1 William D. Vacca,2 Michael C. Cushing, and John T. Rayner Institute for Astronomy, University of Hawaii, Honolulu, HI 96822; [email protected], [email protected], [email protected] Received 2002 October 29; accepted 2002 November 8 ABSTRACT. We present a method for correcting near-infrared medium-resolution spectra for telluric absorption. The method makes use of a spectrum of an A0 V star, observed near in time and close in air mass to the target object, and a high-resolution model of Vega, to construct a telluric correction spectrum that is free of stellar absorption features. The technique was designed specifically to perform telluric corrections on spectra obtained with SpeX, a 0.8–5.5 mm medium-resolution cross-dispersed spectrograph at the NASA Infrared Telescope Facility, and uses the fact that for medium resolutions there exist spectral regions uncontaminated by atmospheric absorption lines. However, it is also applicable (in a somewhat modified form) to spectra obtained with other near-infrared spectrographs. An IDL-based code that carries out the procedures is available for downloading via the World Wide Web. 1. INTRODUCTION are designed to study the H lines in the spectrum of the object Ground-based near-infrared spectroscopy (∼1–5 mm) has of interest. One technique commonly adopted in order to pre- always been hampered by the strong and variable absorption serve the other desirable qualities of A stars as telluric and flux features due to the Earth’s atmosphere. -
A Tale of Two Exoplanets: the Inflated Atmospheres of the Hot Jupiters HD 189733 B and Corot-2 B
A Tale of Two Exoplanets: the Inflated Atmospheres of the Hot Jupiters HD 189733 b and CoRoT-2 b K. Poppenhaeger1,3, S.J. Wolk1, J.H.M.M. Schmitt2 1Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 2Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany 3NASA Sagan Fellow Abstract. Planets in close orbits around their host stars are subject to strong irradiation. High-energy irradiation, originating from the stellar corona and chromosphere, is mainly responsible for the evaporation of exoplanetary atmospheres. We have conducted mul- tiple X-ray observations of transiting exoplanets in short orbits to determine the extent and heating of their outer planetary atmospheres. In the case of HD 189733 b, we find a surprisingly deep transit profile in X-rays, indicating an atmosphere extending out to 1.75 optical planetary radii. The X-ray opacity of those high-altitude layers points towards large densities or high metallicity. We preliminarily report on observations of the Hot Jupiter CoRoT-2 b from our Large Program with XMM-Newton, which was conducted recently. In addition, we present results on how exoplanets may alter the evolution of stellar activity through tidal interaction. 1. Exoplanetary transits in X-rays Close-in exoplanets are expected to harbor extended atmospheres and in some cases lose mass through atmospheric evaporation, driven by X-ray and extreme UV emission from the host star (Lecavelier des Etangs et al. 2004; Murray-Clay et al. 2009, for exmaple). Direct observational evidence for such extended atmospheres has been collected at UV wavelengths (Vidal-Madjar et al. -
New Transit Measurements of WASP 43B and HD 189733B
Robotic Telescopes, Student Research and Education (RTSRE) Proceedings Conference Proceedings, Hilo, Hawaii, USA, Jul 23-27, 2018 Fitzgerald, M., Bartlett, S., Salimpour, S., Eds. Vol. 2, No. 1, (2019) ISBN 978-0-6483996-1-2 / doi : 10.32374/rtsre.2019.009 / CC BY-NC-ND license Peer Reviewed Article. rtsre.org/ojs New Transit Measurements of WASP 43b and HD 189733b Richard P. Olenick1*, Arthur Sweeney1, Philip Lenzen1, Samantha Garza1, Cecilia Hassan1, Gianna Milton1, Clement Say1, Stephen Flowers2, Nick Bacsewski2, Chris Littler2 Abstract Known exoplanets not only provide excellent targets for students who are learning to acquire data with remote observatories and to process the data but also fulfill a scientific need for repeated measurements to determine the stability of known parameters. We present recent measurements taken by undergraduate students with a remotely accessed telescope at the Dark Skies Observatory Collaborative in West Texas on two well-studied exoplanets. WASP 43b has a published orbital period of 0.81347753 days and its host K7V star has a visual magnitude of 12.4. HD 189733b has a published orbital period of 2.21857312 days around its K1V star of visual magnitude 7.67. Both planets orbit within the corona of their host stars and, as such, appear to experience changes in their orbital periods, transit timings, and other parameters. We examined the historical trends, combined them with our measurements in the mid-transit timings for the stars, and determined there are significant changes. Astronomers– from college students to professionals–need this continued monitoring in order to keep system models up to date. -
CORRECTING for TELLURIC ABSORPTION: METHODS, CASE STUDIES, and RELEASE of the Telfit CODE
The Astronomical Journal, 148:53 (6pp), 2014 September doi:10.1088/0004-6256/148/3/53 C 2014. The American Astronomical Society. All rights reserved. Printed in the U.S.A. CORRECTING FOR TELLURIC ABSORPTION: METHODS, CASE STUDIES, AND RELEASE OF THE TelFit CODE Kevin Gullikson1, Sarah Dodson-Robinson2, and Adam Kraus1 1 Department of Astronomy, University of Texas, 2515 Speedway, Stop C1400, Austin, TX 78712, USA 2 Department of Physics and Astronomy, 217 Sharp Lab, Newark, DE 19716, USA Received 2014 April 25; accepted 2014 June 21; published 2014 August 13 ABSTRACT Ground-based astronomical spectra are contaminated by the Earth’s atmosphere to varying degrees in all spectral regions. We present a Python code that can accurately fit a model to the telluric absorption spectrum present in astronomical data, with residuals of ∼3%–5% of the continuum for moderately strong lines. We demonstrate the quality of the correction by fitting the telluric spectrum in a nearly featureless A0V star, HIP 20264, as well as to a series of dwarf M star spectra near the 819 nm sodium doublet. We directly compare the results to an empirical telluric correction of HIP 20264 and find that our model-fitting procedure is at least as good and sometimes more accurate. The telluric correction code, which we make freely available to the astronomical community, can be used as a replacement for telluric standard star observations for many purposes. Key words: atmospheric effects – instrumentation: spectrographs – techniques: spectroscopic Online-only material: color figures 2 1. INTRODUCTION In this paper we describe Telfit, a code that acts as a wrapper to LBLRTM and allows for easy fitting of the telluric spectrum All ground-based astronomical spectra suffer from contam- in astronomical data.