Can We Communicate with an Alien Star System?
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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. -
Stars and Their Spectra: an Introduction to the Spectral Sequence Second Edition James B
Cambridge University Press 978-0-521-89954-3 - Stars and Their Spectra: An Introduction to the Spectral Sequence Second Edition James B. Kaler Index More information Star index Stars are arranged by the Latin genitive of their constellation of residence, with other star names interspersed alphabetically. Within a constellation, Bayer Greek letters are given first, followed by Roman letters, Flamsteed numbers, variable stars arranged in traditional order (see Section 1.11), and then other names that take on genitive form. Stellar spectra are indicated by an asterisk. The best-known proper names have priority over their Greek-letter names. Spectra of the Sun and of nebulae are included as well. Abell 21 nucleus, see a Aurigae, see Capella Abell 78 nucleus, 327* ε Aurigae, 178, 186 Achernar, 9, 243, 264, 274 z Aurigae, 177, 186 Acrux, see Alpha Crucis Z Aurigae, 186, 269* Adhara, see Epsilon Canis Majoris AB Aurigae, 255 Albireo, 26 Alcor, 26, 177, 241, 243, 272* Barnard’s Star, 129–130, 131 Aldebaran, 9, 27, 80*, 163, 165 Betelgeuse, 2, 9, 16, 18, 20, 73, 74*, 79, Algol, 20, 26, 176–177, 271*, 333, 366 80*, 88, 104–105, 106*, 110*, 113, Altair, 9, 236, 241, 250 115, 118, 122, 187, 216, 264 a Andromedae, 273, 273* image of, 114 b Andromedae, 164 BDþ284211, 285* g Andromedae, 26 Bl 253* u Andromedae A, 218* a Boo¨tis, see Arcturus u Andromedae B, 109* g Boo¨tis, 243 Z Andromedae, 337 Z Boo¨tis, 185 Antares, 10, 73, 104–105, 113, 115, 118, l Boo¨tis, 254, 280, 314 122, 174* s Boo¨tis, 218* 53 Aquarii A, 195 53 Aquarii B, 195 T Camelopardalis, -
Downloads/ Astero2007.Pdf) and by Aerts Et Al (2010)
This work is protected by copyright and other intellectual property rights and duplication or sale of all or part is not permitted, except that material may be duplicated by you for research, private study, criticism/review or educational purposes. Electronic or print copies are for your own personal, non- commercial use and shall not be passed to any other individual. No quotation may be published without proper acknowledgement. For any other use, or to quote extensively from the work, permission must be obtained from the copyright holder/s. i Fundamental Properties of Solar-Type Eclipsing Binary Stars, and Kinematic Biases of Exoplanet Host Stars Richard J. Hutcheon Submitted in accordance with the requirements for the degree of Doctor of Philosophy. Research Institute: School of Environmental and Physical Sciences and Applied Mathematics. University of Keele June 2015 ii iii Abstract This thesis is in three parts: 1) a kinematical study of exoplanet host stars, 2) a study of the detached eclipsing binary V1094 Tau and 3) and observations of other eclipsing binaries. Part I investigates kinematical biases between two methods of detecting exoplanets; the ground based transit and radial velocity methods. Distances of the host stars from each method lie in almost non-overlapping groups. Samples of host stars from each group are selected. They are compared by means of matching comparison samples of stars not known to have exoplanets. The detection methods are found to introduce a negligible bias into the metallicities of the host stars but the ground based transit method introduces a median age bias of about -2 Gyr. -
Thursday, December 22Nd Swap Meet & Potluck Get-Together Next First
Io – December 2011 p.1 IO - December 2011 Issue 2011-12 PO Box 7264 Eugene Astronomical Society Annual Club Dues $25 Springfield, OR 97475 President: Sam Pitts - 688-7330 www.eugeneastro.org Secretary: Jerry Oltion - 343-4758 Additional Board members: EAS is a proud member of: Jacob Strandlien, Tony Dandurand, John Loper. Next Meeting: Thursday, December 22nd Swap Meet & Potluck Get-Together Our December meeting will be a chance to visit and share a potluck dinner with fellow amateur astronomers, plus swap extra gear for new and exciting equipment from somebody else’s stash. Bring some food to share and any astronomy gear you’d like to sell, trade, or give away. We will have on hand some of the gear that was donated to the club this summer, including mirrors, lenses, blanks, telescope parts, and even entire telescopes. Come check out the bargains and visit with your fellow amateur astronomers in a relaxed evening before Christmas. We also encourage people to bring any new gear or projects they would like to show the rest of the club. The meeting is at 7:00 on December 22nd at EWEB’s Community Room, 500 E. 4th in Eugene. Next First Quarter Fridays: December 2nd and 30th Our November star party was clouded out, along with a good deal of the month afterward. If that sounds familiar, that’s because it is: I changed the date in the previous sentence from October to November and left the rest of the sentence intact. Yes, our autumn weather is predictable. Here’s hoping for a lucky break in the weather for our two December star parties. -
Another Unit of Distance (I Like This One Better): Light Year
How far away are the nearest stars? Last time: • Distances to stars can be measured via measurement of parallax (trigonometric parallax, stellar parallax) • Defined two units to be used in describing stellar distances (parsec and light year) Which stars are they? Another unit of distance (I like this A new unit of distance: the parsec one better): light year A parsec is the distance of a star whose parallax is 1 arcsecond. A light year is the distance a light ray travels in one year A star with a parallax of 1/2 arcsecond is at a distance of 2 parsecs. A light year is: • 9.460E+15 meters What is the parsec? • 3.26 light years = 1 parsec • 3.086 E+16 meters • 206,265 astronomical units The distances to the stars are truly So what are the distances to the stars? enormous • If the distance between the Earth and Sun were • First measurements made in 1838 (Friedrich Bessel) shrunk to 1 cm (0.4 inches), Alpha Centauri • Closest star is Alpha would be 2.75 km (1.7 miles) away Centauri, p=0.75 arcseconds, d=1.33 parsecs= 4.35 light years • Nearest stars are a few to many parsecs, 5 - 20 light years 1 When we look at the night sky, which So, who are our neighbors in space? are the nearest stars? Altair… 5.14 parsecs = 16.8 light years Look at Appendix 12 of the book (stars nearer than 4 parsecs or 13 light years) The nearest stars • 34 stars within 13 light years of the Sun • The 34 stars are contained in 25 star systems • Those visible to the naked eye are Alpha Centauri (A & B), Sirius, Epsilon Eridani, Epsilon Indi, Tau Ceti, and Procyon • We won’t see any of them tonight! Stars we can see with our eyes that are relatively close to the Sun A history of progress in measuring stellar distances • Arcturus … 36 light years • Parallaxes for even close stars • Vega … 26 light years are tiny and hard to measure • From Abell “Exploration of the • Altair … 17 light years Universe”, 1966: “For only about • Beta Canum Venaticorum . -
3-D Starmap 15.0 All Stars Within 15 Parsecs (50 Light-Years) of Sol
3-D Starmap 15.0 All stars within 15 parsecs (50 light-years) of Sol. Gl 815 2.0:14.9:-1.0 All units are in parsecs. (1 parsec = 3.26 light-years) 1.5 Gl 792 Stars are plotted in cartesian x,y,z coordinates. 3.2:14.7:-0.2 X-Y plane is the plane of the galaxy. Alderamin 2.3 -2.8:14.5:2.4 +x is Coreward, -x is Rimward, NN 4276 -3.9:14.4:0.4 +y is Spinward, -y is Trailing 1.2 Star data is from HYG database. 3.2 Stars circled in green are likely to host 14.0 human-habitable planets, according to 3 Eta Cephei 1.3 -1.9:13.9:2.9 the HabCat database. Gray lines link each star with its two closest neighbors. 2.9 3.0 Green lines link habitable stars with their two Hip 101516 5.7:13.5:-2.3 closest habitable neighbors. NN 4338 B GJ 1228 -4.1:13.4:-4.8 3.0 1.5:13.4:6.2 Gl 878 2.6 GJ 1270 0.4 Links are labeled with their distance in parsecs. -4.6:13.3:0.3 -1.5:13.3:-3.3 3.1 2.6 Gl 794 NN 4109 Winchell Chung: Nyrath the nearly wise 5.5:13.1:-2.3 2.0 7.0:13.1:1.5 http://www.projectrho.com/starmap.html 13.0 Gl 738 2.3 6.5:13.0:3.4 Gl 875.1 1.9 -1.2:12.9:-5.9 2.2 1.5 1.6 2.2 2.7 NN 4073 4.6:12.6:4.5 Gl 14 -6.1:12.5:-5.5 Gl 52 2.6 Gl 806 -28..6:12.4:0.3 1.3:12.4:0.2 4.4 3.8 NN 3069 BD+27°4120 2.6 Gl 813 BD+31°3767 -8.5:12.3:-2.3 2.4:12.3:-4.1 4.9:12.3:-3.55.1:12.3:0.8 BD+57°2735 -4.8:12.2:-0.7 19 Draconis -1.2:12.1:9.0 1.7 12.0 2.1 1.3 Gl 742 26 Draconis NN 4228 3.0 -2.4:11.9:5.6 -0.2:11.9:7.6 4.3:11.6.9:-7.4 1.1 2.5 3.8 1.7 2.4 1.9 35 Gamma Cephei GJ 1243 2.1 2.9 -6.4:11.6:3.6 1.9:11.6:2.1 NN 3117 2.3 NN 4040 2.8 -9.5:11.5:0.6 1.9 2.1 4.1 3.4:11.5:6.4 -
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. -
UNSC Science and Technology Command
UNSC Science and Technology Command Earth Survey Catalogue: Official Name/(Common) Star System Distance Coordinates Remarks/Status 18 Scorpii {TCP:p351} 18 Scorpii {Fact} 45.7 LY 16h 15m 37s Diameter: 1,654,100km (1.02R*) {Fact} -08° 22' 06" {Fact} Spectral Class: G2 Va {Fact} Surface Temp.: 5,800K {Fact} 18 Scorpii ?? (Falaknuma) 18 Scorpii {Fact} 45.7 LY 16h 15m 37s UNSC HQ base on world. UNSC {TCP:p351} {Fact} -08° 22' 06" recruitment center in the city of Halkia. {TCP:p355} Constellation: Scorpio 111 Tauri 111 Tauri {Fact} 47.8 LY 05h:24m:25.46s Diameter: 1,654,100km (1.19R*) {Fact} +17° 23' 00.72" {Fact} Spectral Class: F8 V {Fact} Surface Temp.: 6,200K {Fact} Constellation: Taurus 111 Tauri ?? (Victoria) 111 Tauri {Fact} 47.8 LY 05:24:25.4634 UNSC colony. {GoO:p31} {Fact} +17° 23' 00.72" Constellation: Taurus Location of a rebel cell at Camp New Hope in 2531. {GoO:p31} 51 Pegasi {Fact} 51 Pegasi {Fact} 50.1 LY 22h:57m:28s Diameter: 1,668,000km (1.2R*) {Fact} +20° 46' 7.8" {Fact} Spectral Class: G4 (yellow- orange) {Fact} Surface Temp.: Constellation: Pegasus 51 Pegasi-B (Bellerophon) 51 Pegasi 50.1 LY 22h:57m:28s Gas giant planet in the 51 Pegasi {Fact} +20° 46' 7.8" system informally named Bellerophon. Diameter: 196,000km. {Fact} Located on the edge of UNSC territory. {GoO:p15} Its moon, Pegasi Delta, contained a Covenant deuterium/tritium refinery destroyed by covert UNSC forces in 2545. {GoO:p13} Constellation: Pegasus 51 Pegasi-B-1 (Pegasi 51 Pegasi 50.1 LY 22h:57m:28s Moon of the gas giant planet 51 Delta) {GoO:p13} +20° 46' 7.8" Pegasi-B in the 51 Pegasi star Constellation: Pegasus system; a Covenant stronghold on the edge of UNSC territory. -
Cyclic-Permutation Invariant Networks for Modeling Periodic Sequential Data: Application to Variable Star Classification
Cyclic-Permutation Invariant Networks for Modeling Periodic Sequential Data: Application to Variable Star Classification Keming Zhang∗ Joshua S. Bloom Department of Astronomy Department of Astronomy University of California at Berkeley University of California at Berkeley Berkeley, CA 94720 Berkeley, CA 94720 [email protected] [email protected] Abstract Current recurrent and convolutional neural network (RNN; CNN) architectures are sub-optimal for modeling periodic sequences because of their acyclic topology. Here, we present cyclic-permutation invariant networks, a new type of CNN for which the invariance to cyclic-permutations, or phase shifts, is guaranteed by representing data in phase-space and performing convolutions in polar coordinates, which we implement by means of “Symmetry Padding.” Across three different datasets of periodic variable star light-curves (time-series of brightness) [1, 2, 3], we show that two particular implementations of the cyclic-permutation invariant network: the iTCN and the iResNet, consistently outperform both non-invariant versions of the same network, as well as previous state-of-the-art approaches including Random Forests. This methodology is first presented in [4] and is applicable to a wide range of science domains where periodic data abounds due to physical symmetries. 1 Introduction Strictly periodic data is common in the physical sciences where periodicity occurs both spatially and temporally. Neural networks for which invariances arising from periodicity are explicitly considered either in the input features or the loss function, have been previously applied to particle physics [5] and atomic physics/chemistry [6]. In this study, we focus on periodic time series arising from variable stars, which is important to many sub-fields of astronomy, including the study of the cosmic distance ladder, galactic archaeology, and stellar evolution. -
MAN-KZIN WARS V Created by Larry Niven with Jerry Pournelle S.M
MAN-KZIN WARS V Created by Larry Niven with Jerry Pournelle S.M. Stirling & Thomas T. Thomas MAN-KZIN WARS V This is a work of fiction. All the characters and events portrayed in this book are fictional, and any resemblance to real people or incidents is purely coincidental. Copyright ~ 1992, by Larry Niven All rights reserved, including the right to reproduce this book or portions thereof in any form. A Baen Books Original Baen Publishing Enterprises P.O. Box 1403 Riverdale, NY 10471 ISBN: 0-671-72137-2 Cover art by Stephen Hickman First Printing, October 1992 Printed in the United States of America Distributed by Simon & Schuster 1230 Avenue of the Americas New York, NY 10020 CONTENTS IN THE HALL OF THE MOUNTAIN KING, Jerry Pournelle & S.M. Stirling 7 HEY DIDDLE DIDDLE, Thomas T. Thomas 203 IN THE HALL OF THE MOUNTAIN KING Jerry Pournelle S.M. Sterling Copyright ~ 1992 by Jerry Pournelle & S.M. Stirling ù Prologue Durvash the tnuctipun knew he was dying. The thought did not bother him overmuch-he was a warrior of a peculiar and desperate kind and had never expected to survive the War-but the consciousness of failure was far worse than the wound along his side. Breath rasped harsh between his fangs. Thin fringed lips drew back from them, fledged with purple blood from his injured airsac. Unbending will kept all fourteen digits splayed on the rough rock; the light gravity of this world helped, as well. Cold wind hooted down from the heights, plucking at him until he came to a crack that was deep enough for a leg and an arm; the long flexible fingers on both wound into irregularities, anchoring him. -
A Green Line Around the Box Means a Habitable Planet Exists in the Starsystem
Hussey 575 BD+30 2494 BD+24 2733 1.5 BD+14 2774 2.5 1.5 1.5 Ross 512 1.5 WO 9502 1.5 BD+17 2785 2 BD+15 3108 G136-101 Sigma Bootis BD+30 2512 1 Struve 1785 1.5 1 2.5 via LP441.33 1.5 BD+24 2786 1.5 1.5 1.5 1.5 1.5 45 Bootis L1344-37 GJ 3966 Ross 863 1.5 Lambda Serpentis Wolf 497 BD+25 2874 1.5 3 via V645 Herc Gliese 625 1 1.5 3.5 via GJ 3910 3 via V645 Herc 1.5 BD-9 3413 GJ-1179 Zeta Herculis 1.5 Eta Bootes 1 Rho Coronae Borealis 1.5 1.5 2.5 via Giclas 258.33 Luyten 758-105 BD+54 1716 1 BD+25 3173 Giclas 179-43 1.5 1.5 1.5 1 3 via Ross 948 3 via WO 9564 3 via GJ 3796 3 via Ross 948 Eta Coronae Borealis Chi Draconis 3 via HYG86887 1 3.5 via V645 Herc 1 Gamma Serpentis 2 BD+17 2611 (VESTA) Arcturus 3 via V645 Herc 3 via BD+21 2763 3.5 via BD+0 2989, DT Virginis 4 via HYG86887&8 Struve 2135 BD+33 2777 14 Herculis Porimma (Gamma Virginis) 3.5 via BD+45 2247 3 via BD+41 2695 1.5 3.5 BD+60 1623 BD+53 1719 THETIS 1.5 Chi Hercules 2 3.5 1.5 1.5 BD+38 3095 3.5 via BD+46 1189 Mu Herculis 4 via WO 9564 CR Draconis BD+52 2045 3 via BD+43 2796 1.5 3 via Giclas 179-43 BD+36 2393 Queen Isabel Star Sigma Draconis 3.5 via BD+43 2796 CE Bootes 1.5 BD+19 2881 1 1.5 1.5 1.5 2.5 I Bootis via BD+45 2247 BD+47 2112 1 4 via EGWD 329, CR Draconis 3 via LP 272-25 4.5 via Ross 948, L 910-10 44 Bootis Aitkens Double Star 1 ADS 10288 3 via BD+61 2068 1.5 Gilese 625 1.5 Vega 3 via Kuiper 79 3 via Giclas 179-43 4 via BD+46 1189, BD+50 2030 Ross 52 Theta Draconis 2 EV Lacertae Gliese 892 BD+39 2947 3 via BD+18 3421 1.5 0.5 Theta Bootis 1.5 3 via EV Lacertae 2.5 via -
Serpens – the Serpent
A JPL Image of surface of Mars, and JPL Ingenuity Helicioptor illustration, in flight Monthly Meeting May 10th at 7:00 PM at HRPO, and via Jitsi (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory, will also broadcast via. (meet.jit.si/BRASMeet). PRESENTATION: Dr. Alan Hale, professional astronomer and co-discoverer of Comet Hale-Bopp, among other endeavors. What's In This Issue? President’s Message Member Meeting Minutes Business Meeting Minutes Outreach Report Light Pollution Committee Report Globe at Night SubReddit and Discord Messages from the HRPO REMOTE DISCUSSION Solar Viewing International Astronomy Day American Radio Relay League Field Day Observing Notes: Serpens - The Serpent & Mythology Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society BRAS YouTube Channel Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 20 May 2021 President’s Message Ahhh, welcome to May, the last pleasant month in Louisiana before the start of the hurricane season and the brutal summer months that follow. April flew by pretty quickly, and with the world slowly thawing from the long winter, why shouldn’t it? To celebrate, we decided we’re going to try to start holding our monthly meetings at Highland Road Park Observatory again, only with the added twist of incorporating an on-line component for those who for whatever reason don’t feel like making it out. To that end, we’ll have both our usual live broadcast on the BRAS YouTube channel and the Brasmeet page on Jitsi—which is where our out of town guests and, at least this month, our guest speaker can join us.