November 2019 BRAS Newsletter
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
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. -
1903Apj 18. .3415 the SPECTRUM of O CETL' by Joel Stebbins. On
.3415 18. 1903ApJ THE SPECTRUM OF o CETL' By Joel Stebbins. On account of the great instrumental power required for the observation of the spectra of faint objects, changes in the spectra of long-period variable stars have not been well studied. In fact, there is no star which undergoes a large variation in bright- ness whose spectrum has been systematically followed from maxi- mum to minimum, or vice versa. It is proposed to give here the results of a study of the spectrum of o Ceti> or Mira, made, at the suggestion of Director Campbell, with the thirty-six-inch refractor of the Lick Observatory, from June 1902 to January 1903. During this period the star faded in brightness from 3.8 to 9.0 magnitude. The first photograph of the spectrum was obtained about three weeks after the predicted time of maximum, and a series of plates was secured covering the interval to mini- mum. No negatives were obtained after the star had again begun to increase in brightness. The most important articles concerning the spectrum of Mira are those of Vogel,2 Sidgreaves,3 and Campbell.4 Neither Vogel nor Sidgreaves followed the star long enough to find much change in its spectrum, and Campbell’s work was mainly in con- nection with observations of the star for radial velocity, with the Mills spectrograph. INSTRUMENTS AND METHODS. The spectrograph used in my observations was the one employed rby Messrs. Campbell and Wright in their work on 1 “ Dissertation in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the University of California,” Lick Observatory Bulletin No. -
Technical Activities 1983 Center for Basic Standards
Technical Activities 1983 Center for Basic Standards U S. DEPARTMENT OF COMMERCE National Bureau of Standards National Measurement Laboratory Center for Basic Standards Washington, DC 20234 November 1983 Final Issued January 1984 Prepared for: U S. DEPARTMENT OF COMMERCE National Bureau of Standards Qc /ashington, DC 20234 1 00 -USk p p p I p p V i I » i » i i » i [i fi n NBSIR 83-2793 TECHNICAL ACTIVITIES 1983 CENTER FOR BASIC STANDARDS Karl G. Kessler, Director U.S. DEPARTMENT OF COMMERCE National Bureau of Standards National Measurement Laboratory Center for Basic Standards Washington, DC 20234 November 1 983 Final Issued January 1984 Prepared for: U.S. DEPARTMENT OF COMMERCE National Bureau of Standards Washington, DC 20234 U.S. DEPARTMENT OF COMMERCE, Malcolm Baidrige. Secretary NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director TABLE OF CONTENTS Part II Page Technical Activities: Introduction 1 Quantum Metrology Group 2 Electricity Division 21 Temperature and Pressure Division 81 Length and Mass Division 123 Time and Frequency Division 135 Quantum Physics Division 187 i i I 1 I II II i li 1 1 INTRODUCTION This book is Part II of the 1983 Annual Report of the Center for Basic Standards and contains a summary of the technical activities of the Center for the period October 1, 1982 to September 30, 1983. The Center is one of the five resources and operating units in the National Measurement Laboratory. The summary of activities is organized in six sections, one for the technical activities of the Quantum Metrology Group, and one each for the five divisions of the Center. -
September 2020 BRAS Newsletter
A Neowise Comet 2020, photo by Ralf Rohner of Skypointer Photography Monthly Meeting September 14th at 7:00 PM, via Jitsi (Monthly meetings are on 2nd Mondays at Highland Road Park Observatory, temporarily during quarantine at meet.jit.si/BRASMeets). GUEST SPEAKER: NASA Michoud Assembly Facility Director, Robert Champion What's In This Issue? President’s Message Secretary's Summary Business Meeting Minutes Outreach Report Asteroid and Comet News Light Pollution Committee Report Globe at Night Member’s Corner –My Quest For A Dark Place, by Chris Carlton Astro-Photos by BRAS Members Messages from the HRPO REMOTE DISCUSSION Solar Viewing Plus Night Mercurian Elongation Spooky Sensation Great Martian Opposition Observing Notes: Aquila – The Eagle Like this newsletter? See PAST ISSUES online back to 2009 Visit us on Facebook – Baton Rouge Astronomical Society Baton Rouge Astronomical Society Newsletter, Night Visions Page 2 of 27 September 2020 President’s Message Welcome to September. You may have noticed that this newsletter is showing up a little bit later than usual, and it’s for good reason: release of the newsletter will now happen after the monthly business meeting so that we can have a chance to keep everybody up to date on the latest information. Sometimes, this will mean the newsletter shows up a couple of days late. But, the upshot is that you’ll now be able to see what we discussed at the recent business meeting and have time to digest it before our general meeting in case you want to give some feedback. Now that we’re on the new format, business meetings (and the oft neglected Light Pollution Committee Meeting), are going to start being open to all members of the club again by simply joining up in the respective chat rooms the Wednesday before the first Monday of the month—which I encourage people to do, especially if you have some ideas you want to see the club put into action. -
Arxiv:1603.05644V1
Accepted by ApJ: March 16, 2016 Constraints on Planetesimal Collision Models in Debris Disks Meredith A. MacGregor1, David J. Wilner1, Claire Chandler2, Luca Ricci1, Sarah T. Maddison3, Steven R. Cranmer4, Sean M. Andrews1, A. Meredith Hughes5, Amy Steele6 ABSTRACT Observations of debris disks offer a window into the physical and dynamical properties of planetesimals in extrasolar systems through the size distribution of dust grains. In particular, the millimeter spectral index of thermal dust emission encodes information on the grain size distribution. We have made new VLA ob- servations of a sample of seven nearby debris disks at 9 mm, with 3′′ resolution and ∼ 5 µJy/beam rms. We combine these with archival ATCA observations of eight additional debris disks observed at 7 mm, together with up-to-date observa- tions of all disks at (sub)millimeter wavelengths from the literature to place tight constraints on the millimeter spectral indices and thus grain size distributions. The analysis gives a weighted mean for the slope of the power law grain size distribution, n(a) ∝ a−q, of hqi =3.36 ± 0.02, with a possible trend of decreasing q for later spectral type stars. We compare our results to a range of theoretical models of collisional cascades, from the standard self-similar, steady-state size distribution (q = 3.5) to solutions that incorporate more realistic physics such as alternative velocity distributions and material strengths, the possibility of a cutoff at small dust sizes from radiation pressure, as well as results from detailed dynamical calculations of specific disks. Such effects can lead to size distributions consistent with the data, and plausibly the observed scatter in spectral indices. -
Cosmic Evolution Through Uv Surveys (Cetus) Final Report
COSMIC EVOLUTION THROUGH UV SURVEYS (CETUS) FINAL REPORT Thematic Activity: Project (probe mission concept) Program: Electromagnetic observations from space Authors of Final Report: Jonathan Arenberg, Northrop Grumman Corporation Sally Heap, Univ. of Maryland, [email protected] Tony Hull, Univ. of New Mexico Steve Kendrick, Kendrick Aerospace Consulting LLC Bob Woodruff, Woodruff Consulting Scientific Contributors: Maarten Baes, Rachel Bezanson, Luciana Bianchi, David Bowen, Brad Cenko, Yi-Kuan Chiang, Rachel Cochrane, Mike Corcoran, Paul Crowther, Simon Driver, Bill Danchi, Eli Dwek, Brian Fleming, Kevin France, Pradip Gatkine, Suvi Gezari, Lea Hagen, Chris Hayward, Matthew Hayes, Tim Heckman, Edmund Hodges-Kluck, Alexander Kutyrev, Thierry Lanz, John MacKenty, Steve McCandliss, Harvey Moseley, Coralie Neiner, Goren Östlin, Camilla Pacifici, Marc Rafelski, Bernie Rauscher, Jane Rigby, Ian Roederer, David Spergel, Dan Stark, Alexander Szalay, Bryan Terrazas, Jonathan Trump, Arjun van der Wel, Sylvain Veilleux, Kate Whitaker, Isak Wold, Rosemary Wyse Technical Contributors: Jim Burge, Kelly Dodson, Chip Eckles, Brian Fleming, Jamie Kennea, Gerry Lemson, John MacKenty, Steve McCandliss, Greg Mehle, Shouleh Nikzad, Trent Newswander, Lloyd Purves, Manuel Quijada, Ossy Siegmund, Dave Sheikh, Phil Stahl, Ani Thakar, John Vallerga, Marty Valente, the Goddard IDC/MDL. September 2019 Cosmic Evolution Through UV Surveys (CETUS) TABLE OF CONTENTS INTRODUCTION TO CETUS ................................................................................................................ -
Publications Year: 2012 1. Auriere, M
Publications year: 2012 1. Auriere, M., Konstantinova-Antova, R., Petit, P., Charbonnel, C., Van Eck, S., Donati, J.-F., Lignieres, F., Roudier, T., 14 Ceti: a probable Ap-star-descendant entering the Hertzsprung gap, 2012, A&A, 543, A118 2. Bachev, R., Rapid optical variability of QSO GB6 J1604+5714, 2012, ATel, 4184, 1 3. Bachev, R., Semkov, E., Strigachev, A., Gupta, A. C., Gaur, H., Mihov, B., Boeva, S., Slavcheva- Mihova, L., The nature of the intra-night optical variability in blazars, 2012, MNRAS, 424, 2625– 2634 4. Bachev, R., Peneva, S., Recent optical activity of flaring blazars, 2012, ATel, 4437, 1 5. Bachev, R., Spassov, B., Ibryamov, S., Boeva, S., Stoyanov, K., Semkov, E., Peneva, S., Strigachev, A., No evidence for enhanced optical emission from BL Lacertae, 2012, ATel, 4568, 1 6. Boeva, S., Bachev, R., Antov, A., Tsvetkova, S., Stoyanov, K. A., Low State of KR Aurigae (2008 - 2010), 2012, Publ. Astron. Society R. Boskovic, 11, 369-373, ISBN 978-86-89035-01-8 7. Borisov, G., Bonev, T., Iliev, I., Stateva, I., Low and high resolution spectroscopy of the comet C/ 2009 R1 (McNaught), 2012, Bulgarian Astronomical Journal, 18(1), 47-55, 8. Borisov, G.; Stanchev, O., Assigning WCS Standards to Rozhen Fits Archive. Preliminary Tests, 2012, Publ. Astron. Society R. Boskovic, 11, 253-257 9. Borisova, A. P., Hambaryan, V. V., Innis, J. L., Bayesian approach to the cyclic activity of CF Oct, 2012, MNRAS, 420, 2539-2545 10. Borisova, A., Hambaryan, V., Laskov, L., Bayesian Probability Theory in Astronomy: Looking for Stellar Activity Cycles in Photometric Data-Series, 2012, Publ. -
194 9 Ce Le B Rating 65 Ye Ars O F Br Inging As Tr on Omy T O No Rth Te X As 2
1949 Celebrating 65 Years of Bringing Astronomy to North Texas 2014 Contact information: Inside this issue: Info Officer (General Info) – [email protected] Website Administrator – [email protected] Page Postal Address: November Club Calendar 3 Fort Worth Astronomical Society Celestial Events 4 c/o Matt McCullar 5801 Trail Lake Drive Sky Chart 5 Fort Worth, TX 76133 Moon Phase Calendar 6 Web Site: http://www.fortworthastro.org Facebook: http://tinyurl.com/3eutb22 Lunar Occultations/Conjs 7 Twitter: http://twitter.com/ftwastro Yahoo! eGroup (members only): http://tinyurl.com/7qu5vkn Mercury/Venus Chart 8 Officers (2014-2015): Mars/Minor Planets Charts 9 President – Bruce Cowles, [email protected] Jupiter Charts 10 Vice President – Russ Boatwright, [email protected] Sec/Tres – Michelle Theisen, [email protected] Planet Vis & ISS Passes 11 Board Members: CSAC Event Update 12 2014-2016 Mike Langohr Young Astronomer News 12 Tree Oppermann ‘66 Leonids Remembered 13 2013-2015 Bill Nichols Cloudy Night Library 15 Jim Craft Cover Photo: Monthly AL Observing Club 17 Composite image taken by FWAS mem- bers: Left to right, from top to bottom— Constellation of the Month 18 Laura Cowles, Mike Ahner, Brian Wortham, Constellation Mythology 19 Shawn Kirchdorfer, Mark Wainright, Phil Stage, Patrick McMahon, Dennis Webb, Ben Prior Club Meeting Minutes 20 Hudgens, Shawn Kirchdorfer, John McCrea, and Chris Mlodnicki General Club Information 21 That’s A Fact 21 Observing Site Reminders: Be careful with fire, mind all local burn bans! Full Moon Name 21 Dark Site Usage Requirements (ALL MEMBERS): FWAS Foto Files 22 Maintain Dark-Sky Etiquette (http://tinyurl.com/75hjajy) Turn out your headlights at the gate! Sign the logbook (in camo-painted storage shed. -
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, -
The Observer, November
The OBSERVER The Newsletter of the Twin City Amateur Astronomers, Inc. November 2001 Volume 26, Number 11 Adventures in Meteor Hunting — Duane Yockey In This Issue: REETINGS to my brother and and binoculars just in case the meteors sister sky watchers, didn't live up to their billing. Saturday G was clear here in central Illinois, and • Meteor Hunting Adventures ...1 when I got back from a Duane shows that he has the The long awaited day play at Illinois State right stuff as he tears after the of the Leonid meteor University around Leonids and finds them! shower arrived Satur- 10:30 p.m. the sky was day. I was really still showing lots of • TCAA Calendar ........................1 looking forward to stars. I called Laura Use our calendar to mark going out to the (my oldest daughter), your calendar. observatory with who said the skies were other Twin City clear down in southern • TCAA Annual Holiday Bash....3 Amateur Indiana and I could Party like it’s, um, 2001, at Astronomers and see- drive down there, if the Vic & Cindy’s! ............................ ing the "show" from clouds rolled in (ha, 2:00 a.m. to 6:00 a.m. ha). I assured her that • Club Notes................................4 early Sunday morn- the sky would cooper- Wow, it’s been a busy month! ing. So I packed my ate, and it was looking car early with a lawn good then, and I wished • Software Review: DSE ...........5 chair and threw in my her good luck (if she And just think, if you never telescope, star charts turn to page 5, you’ll never know continued on next page what DSE stands for.. -
Stdt0903for Pub00.Pub
Star Dust National Capital Astronomers, Inc. http://capitalastronomers.org Volume 62, Number 1 September 2003 ISSN 0898-7548 September Speaker: Dr. David E. Smith, The President’s “Update on Mars Research: What’s been Corner Discovered and Future Missions” Welcome to the 2003-2004 NCA Submitted by Jeff Guerber series of meetings. I hope people have been able to observe Mars Dr. David E. Smith will present the fea- Terrestrial Physics at NASA Goddard. He through the rain and clouds. tured talk for the September 6 meeting of was the Principal Investigator for the Mars the National Capital Astronomers. Orbiter Laser Altimeter (MOLA) instru- I’ve been interested in rejoining the Astronomical League and there are Dr. Smith will give us an update on Mars ment on Mars Global Surveyor, and is cur- “pro” and “con” paragraphs in this research: what's been discovered by the rently for the Mercury MESSENGER La- month’s issue of Star Dust on this. recent missions (Mars Global Surveyor ser Altimeter. He is also a member of the Please vote on this (once) at the Sep- and Mars Odyssey), and look ahead to the science team for the DAWN mission to as- upcoming ones. The meeting will be held tember meeting or by contacting teroids Ceres and Vesta. He received his Nancy Grace Roman. at 3:00 P.M. in the Bethesda-Chevy bachelor's and master's degrees from the Chase Regional Services Center of University of Durham, and his Ph.D. in Note that the October meeting will Montgomery County, 4805 Edgemoor satellite geodesy in 1966 from the Univer- be on the 11th rather than the 4th to Lane (Second Floor), Bethesda, MD. -
407 a Abell Galaxy Cluster S 373 (AGC S 373) , 351–353 Achromat
Index A Barnard 72 , 210–211 Abell Galaxy Cluster S 373 (AGC S 373) , Barnard, E.E. , 5, 389 351–353 Barnard’s loop , 5–8 Achromat , 365 Barred-ring spiral galaxy , 235 Adaptive optics (AO) , 377, 378 Barred spiral galaxy , 146, 263, 295, 345, 354 AGC S 373. See Abell Galaxy Cluster Bean Nebulae , 303–305 S 373 (AGC S 373) Bernes 145 , 132, 138, 139 Alnitak , 11 Bernes 157 , 224–226 Alpha Centauri , 129, 151 Beta Centauri , 134, 156 Angular diameter , 364 Beta Chamaeleontis , 269, 275 Antares , 129, 169, 195, 230 Beta Crucis , 137 Anteater Nebula , 184, 222–226 Beta Orionis , 18 Antennae galaxies , 114–115 Bias frames , 393, 398 Antlia , 104, 108, 116 Binning , 391, 392, 398, 404 Apochromat , 365 Black Arrow Cluster , 73, 93, 94 Apus , 240, 248 Blue Straggler Cluster , 169, 170 Aquarius , 339, 342 Bok, B. , 151 Ara , 163, 169, 181, 230 Bok Globules , 98, 216, 269 Arcminutes (arcmins) , 288, 383, 384 Box Nebula , 132, 147, 149 Arcseconds (arcsecs) , 364, 370, 371, 397 Bug Nebula , 184, 190, 192 Arditti, D. , 382 Butterfl y Cluster , 184, 204–205 Arp 245 , 105–106 Bypass (VSNR) , 34, 38, 42–44 AstroArt , 396, 406 Autoguider , 370, 371, 376, 377, 388, 389, 396 Autoguiding , 370, 376–378, 380, 388, 389 C Caldwell Catalogue , 241 Calibration frames , 392–394, 396, B 398–399 B 257 , 198 Camera cool down , 386–387 Barnard 33 , 11–14 Campbell, C.T. , 151 Barnard 47 , 195–197 Canes Venatici , 357 Barnard 51 , 195–197 Canis Major , 4, 17, 21 S. Chadwick and I. Cooper, Imaging the Southern Sky: An Amateur Astronomer’s Guide, 407 Patrick Moore’s Practical