A Catalogue of Star Clusters Shown on the Franklin-Adams Chart Plates” by P.J
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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. -
Staff, Visiting Scientists and Graduate Students at the Pescara Center December 2012 2
Staff, Visiting Scientists and Graduate Students at the Pescara Center December 2012 2 Contents ICRANet Faculty Staff……………………………………………………………………. p. 17 Adjunct Professors of the Faculty .……………………………………………………… p. 36 Lecturers…………………………………………………………………………………… p. 64 Research Scientists ……………………………………………………………………….. p. 76 Visiting Scientists ………………………………………………………………………... p. 86 IRAP Ph. D. Students ……………………………………………………………………. p. 103 IRAP Ph. D. Erasmus Mundus Students………………………………………………. p. 123 Administrative and Secretarial Staff …………………………………………………… p. 135 3 4 ICRANet Faculty Staff Belinski Vladimir ICRANet Bianco Carlo Luciano University of Rome “Sapienza” and ICRANet Einasto Jaan Tartu Observatory, Estonia Novello Mario Cesare Lattes-ICRANet Chair CBPF, Rio de Janeiro, Brasil Rueda Jorge A. University of Rome “Sapienza” and ICRANet Ruffini Remo University of Rome “Sapienza” and ICRANet Vereshchagin Gregory ICRANet Xue She-Sheng ICRANet 5 Adjunct Professors Of The Faculty Aharonian Felix Albert Benjamin Jegischewitsch Markarjan Chair Dublin Institute for Advanced Studies, Dublin, Ireland Max-Planck-Institut für Kernphysis, Heidelberg, Germany Amati Lorenzo Istituto di Astrofisica Spaziale e Fisica Cosmica, Italy Arnett David Subramanyan Chandrasektar- ICRANet Chair University of Arizona, Tucson, USA Chakrabarti Sandip P. Centre for Space Physics, India Chardonnet Pascal Université de la Savoie, France Chechetkin Valeri Mstislav Vsevolodich Keldysh-ICRANet Chair Keldysh institute for Applied Mathematics Moscow, Russia Damour Thibault Joseph-Louis -
Open Cluster NGC 188 Explored with Astrosat 9 December 2020, by Tomasz Nowakowski
Open cluster NGC 188 explored with AstroSat 9 December 2020, by Tomasz Nowakowski Discovered in 1825, NGC 188 is an open cluster in the constellation Cepheus, located some 5,400 light years away from the Earth. It has a solar metallicity, a radius of about 11.8 light years, reddening at a level of 0.036, and its age is estimated to be 7 billion years. It is one of the oldest and well studied OCs in our galaxy. In order to learn more about the member stars of NGC 188, a team of astronomers led by Sharmila Rani of the Indian Institute of Astrophysics in Bengaluru, India, has performed a photometric study of this cluster with the main goal of identifying its ultraviolet-bright stars. For this purpose, they used AstroSat's Ultraviolet Imaging Telescope (UVIT). "In this study, we present the results of the UV UVIT image of NGC 188 obtained by combining images imaging of the NGC 188 in two FUV [far-ultraviolet] in NUV (N279N) and FUV (F148W) channels. Yellow and one NUV [near-ultraviolet] ?lters using UVIT on and blue color corresponds to NUV and FUV detections, AstroSat. We characterize the UV bright stars respectively. Credit: Rani et al., 2020. identi?ed in this cluster by analysing SEDs [spectral energy distributions] to throw light on their formation and evolution," the astronomers wrote in the paper. Indian researchers have carried out ultraviolet photometric observations of an old open cluster FUV observations detected hot and bright blue known as NGC 188. Results of the study, straggler stars (BSSs), one hot subdwarf, and one conducted with the AstroSat spacecraft, provide white dwarf candidate. -
Winter Constellations
Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the Orion Nebula. -
![Arxiv:1606.06587V1 [Astro-Ph.SR] 21 Jun 2016 Rpitsbitdt Elsevier to Submitted Preprint Sn MS Aao.W Bandtecutrsdsac Fro Distance Cluster’S the Obtained We Catalog](https://docslib.b-cdn.net/cover/6305/arxiv-1606-06587v1-astro-ph-sr-21-jun-2016-rpitsbitdt-elsevier-to-submitted-preprint-sn-ms-aao-w-bandtecutrsdsac-fro-distance-cluster-s-the-obtained-we-catalog-196305.webp)
Arxiv:1606.06587V1 [Astro-Ph.SR] 21 Jun 2016 Rpitsbitdt Elsevier to Submitted Preprint Sn MS Aao.W Bandtecutrsdsac Fro Distance Cluster’S the Obtained We Catalog
2MASS photometry and kinematical studies of open cluster NGC 188 W. H. Elsanhourya,b1, A. A. Haroona,c, N. V. Chupinad, S. V. Vereshchagind, Devesh P. Sariyae2, R. K. S. Yadav f , Ing-Guey Jiange aAstronomy Department, National Research Institute of Astronomy and Geophysics (NRIAG) 11421, Helwan, Cairo, Egypt bPhysics Department, Faculty of Science, Northern Border University, Rafha Branch, Saudi Arabia cAstronomy Department, Faculty of Science, King Abdul Aziz University, Jeddah, Saudi Arabia dInstitute of Astronomy Russian Academy of Sciences (INASAN),48 Pyatnitskaya st., Moscow, Russia eDepartment of Physics and Institute of Astronomy, National Tsing Hua University, Hsin-Chu, Taiwan f Aryabhatta Research Institute of observational sciencES (ARIES), Manora Peak Nainital 263 002, India. Abstract In this paper, we present our results for the photometric and kinematical studies of old open cluster NGC 188. We determined various astrophysical parameters like limited radius, core and tidal radii, distance, luminosity and mass functions, total mass, relaxation time etc. for the cluster using 2MASS catalog. We obtained the cluster’s distance from the Sun as 1721 41 pc and log (age)= 9.85 0.05 at Solar metallicity. The relaxation time of the cluster is smaller± than the estimated cluster± age which suggests that the cluster is dynamically relaxed. Our results agree with the values mentioned in the literature. We also determined the clusters apex coordinates as (281◦.88, 44◦.76) using AD-diagram method. Other kinematical parameters like space velocity components,− cluster center and elements of Solar motion etc. have also been computed. Keywords: Open clusters- Color-magnitude diagram- Kinematics- AD diagram 1. -
Apus Constellation Visible at Latitudes Between +5° and -90°
Apus Constellation Visible at latitudes between +5° and -90°. Best visible at 21:00 (9 p.m.) during the month of July. Apus is a small constellation in the southern sky. It represents a bird-of-paradise, and its name means "without feet" in Greek because the bird-of-paradise was once wrongly believed to lack feet. First depicted on a celestial globe by Petrus Plancius in 1598, it was charted on a star atlas by Johann Bayer in his 1603 Uranometria. The French explorer and astronomer Nicolas Louis de Lacaille charted and gave the brighter stars their Bayer designations in 1756. The five brightest stars are all reddish in hue. Shading the others at apparent magnitude 3.8 is Alpha Apodis, an orange giant that has around 48 times the diameter and 928 times the luminosity of the Sun. Marginally fainter is Gamma Apodis, another ageing giant star. Delta Apodis is a double star, the two components of which are 103 arcseconds apart and visible with the naked eye. Two star systems have been found to have planets. Apus was one of twelve constellations published by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman who had sailed on the first Dutch trading expedition, known as the Eerste Schipvaart, to the East Indies. It first appeared on a 35-cm diameter celestial globe published in 1598 in Amsterdam by Plancius with Jodocus Hondius. De Houtman included it in his southern star catalogue in 1603 under the Dutch name De Paradijs Voghel, "The Bird of Paradise", and Plancius called the constellation Paradysvogel Apis Indica; the first word is Dutch for "bird of paradise". -
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. -
Cadas Transit Magazine
TRANSIT The January 2011 Newsletter of NEXT MEETING 14 January 2011, 7.15 pm for a 7.30 pm start Wynyard Planetarium Galaxies with proper names Dave Newton, Sunderland A.S. Contents p.2 Editorial p.2 Letters: I really wish I didn't have to write this…!; Weather predictions Neil Haggath; Keith Johnson Observation reports & planning p.4 Skylights – January 2011 Rob Peeling p.7 Total lunar eclipse, 21 December 2010 (1) Keith Johnson p.8 Total lunar eclipse, 21 December 2010 (2) John McCue General articles p.8 Star of wonder John Crowther p.10 Look again at the Big Dipper! Andy Fleming p.11 Chasing chickens Ray Worthy The Transit quiz p.15 Answers to December's quiz p.16 January's quiz 1 Editorial Rod Cuff December's weather probably sorted out the really hardy observers from the rest. Beautiful as some of the crystal-clear nights were, I used the fact that often the stars appeared to be twinkling wildly to convince myself that seeing would be poor and therefore I needn't feel obliged to stand for hours with snow half-way up my calves and in temperatures of many degrees below freezing. And so I studied last month's lunar eclipse from the relative warmth of a downstairs room with a clear north-west view, knowing that the aforesaid hardy observers would be bound to come up trumps – and so it proved. Take a bow, Keith Johnson and John McCue, whose photographic output appears in this issue. This month there is of course another eclipse, this time a partial solar eclipse visible at sunrise on 4 January. -
Exodata: a Python Package to Handle Large Exoplanet Catalogue Data
ExoData: A Python package to handle large exoplanet catalogue data Ryan Varley Department of Physics & Astronomy, University College London 132 Hampstead Road, London, NW1 2PS, United Kingdom [email protected] Abstract Exoplanet science often involves using the system parameters of real exoplanets for tasks such as simulations, fitting routines, and target selection for proposals. Several exoplanet catalogues are already well established but often lack a version history and code friendly interfaces. Software that bridges the barrier between the catalogues and code enables users to improve the specific repeatability of results by facilitating the retrieval of exact system parameters used in an arti- cles results along with unifying the equations and software used. As exoplanet science moves towards large data, gone are the days where researchers can recall the current population from memory. An interface able to query the population now becomes invaluable for target selection and population analysis. ExoData is a Python interface and exploratory analysis tool for the Open Exoplanet Cata- logue. It allows the loading of exoplanet systems into Python as objects (Planet, Star, Binary etc) from which common orbital and system equations can be calculated and measured parame- ters retrieved. This allows researchers to use tested code of the common equations they require (with units) and provides a large science input catalogue of planets for easy plotting and use in research. Advanced querying of targets are possible using the database and Python programming language. ExoData is also able to parse spectral types and fill in missing parameters according to programmable specifications and equations. Examples of use cases are integration of equations into data reduction pipelines, selecting planets for observing proposals and as an input catalogue to large scale simulation and analysis of planets. -
Open Clusters in Gaia
Sede Amministrativa: Università degli Studi di Padova Dipartimento di Fisica e Astronomia “G. Galilei” Corso di Dottorato di Ricerca in Astronomia Ciclo XXX OPEN CLUSTERS IN GAIA ERA Coordinatore: Ch.mo Prof. Giampaolo Piotto Supervisore: Dr.ssa Antonella Vallenari Dottorando: Francesco Pensabene i Abstract Context. Open clusters (OCs) are optimal tracers of the Milky Way disc. They are observed at every distance from the Galactic center and their ages cover the entire lifespan of the disc. The actual OC census contain more than 3000 objects, but suffers of incom- pleteness out of the solar neighborhood and of large inhomogeneity in the parameter deter- minations present in literature. Both these aspects will be improved by the on-going space mission Gaia . In the next years Gaia will produce the most precise three-dimensional map of the Milky Way by surveying other than 1 billion of stars. For those stars Gaia will provide extremely precise measure- ment of proper motions, parallaxes and brightness. Aims. In this framework we plan to take advantage of the first Gaia data release, while preparing for the coming ones, to: i) move the first steps towards building a homogeneous data base of OCs with the high quality Gaia astrometry and photometry; ii) build, improve and test tools for the analysis of large sample of OCs; iii) use the OCs to explore the prop- erties of the disc in the solar neighborhood. Methods and Data. Using ESO archive data, we analyze the photometry and derive physical parameters, comparing data with synthetic populations and luminosity functions, of three clusters namely NGC 2225, NGC 6134 and NGC 2243. -
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). -
Evolution of Star Clusters in Time-Variable Tidal Fields
Evolution of Star Clusters in Time-Variable Tidal Fields A Thesis Submitted to the Faculty of Drexel University by Ernest N. Mamikonyan in partial fulfillment of the requirement for the degree of Doctor of Philosophy December 12, 2013 Contents 1 Introduction 1 1.1 TypesofStarClusters............................ 2 1.1.1 GlobularClusters .......................... 3 1.1.2 OpenClusters............................ 4 1.2 Mass Function: From Young to Globular . 5 2 Arbitrary Tidal Acceleration 8 2.1 ApproximatingTidalEffects. 9 2.1.1 Tidal Acceleration Tensor . 10 2.2 Stellar Dynamics with KIRA ........................ 11 2.2.1 CircularOrbitinPoint-MassPotential . 14 2.3 GalaxyMergerSimulations . 16 2.3.1 TidalHistories............................ 19 2.4 N-BodySimulations ............................ 24 2.4.1 N-BodyUnits ............................ 26 2.4.2 Scaling ................................ 26 3 Mass Loss Model 30 i 3.1 Accelerated Two-Body Relaxation . 30 3.2 FluctuationsintheJacobiRadius. 34 3.3 Results .................................... 36 3.4 Discussion.................................. 37 3.4.1 Limitations ............................. 40 4 Globular Cluster Mass Functions 44 4.1 MassFunctionEvolution . 47 4.2 Results .................................... 48 4.2.1 SinkParticles ............................ 48 4.2.2 DiskParticles ............................ 50 4.2.3 HaloParticles ............................ 55 5 Conclusions and Future Work 57 Appendix A Implementation of Tidal Fields in KIRA 63 Appendix B Computing Tidal Acceleration from GADGET Output 66 ii List of Figures 1.1 Infrared image of the globular cluster Omega Centauri. It is the most massive cluster in the Galaxy and thought to be a remnant of a dwarf galaxy absorbed by the Milky Way. (NASA/JPL-Caltech/ NOAO/AURA/NSF)............................. 3 1.2 The Pleiades open cluster in the infrared. It is one of the most well- known and spectacular objects in the Galaxy.