| Speckle Interferometry at the U.S. Naval Observatory. XVIII |
May 2012 |
7 pages |
| Authors:
Brian D Mason; William I Hartkopf; Elizabeth A Friedman; NAVAL OBSERVATORY WASHINGTON DC
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 | The results of 2490 intensified CCD observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1462 mean relative positions and range in separation from 056 to 7180, with amean separation of 1481. This is the 18th in this series of papers and covers the ... |
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| Speckle Interferometry at Soar in 2010 and 2011: Measures, Orbits, and Rectilinear Fits |
Feb 2012 |
20 pages |
| Authors:
William I Hartkopf; Andrei Tokovinin; Brian D Mason; NAVAL OBSERVATORY WASHINGTON DC
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| We report on the results of speckle observations at the 4.1 m SOAR telescope in 2010 and 2011. A total of 639 objects were observed. We give 562 measurements of 418 resolved binaries, including 21 pairs resolved for the first time, and upper detection limits for 221 unresolved stars. New orbital elements have been determined for 42 physical pairs, of which 22 are first-time calculations; the rest are corrections, sometimes ... |
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| Visual Orbit Solutions from Observing Techniques Old and New |
Jan 2012 |
9 pages |
| Authors:
Brian D Mason; NAVAL OBSERVATORY WASHINGTON DC
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| For the past couple of decades, the primary double star observational technique utilized at the US Naval Observatory has been speckle interferometry. Our two speckle cameras have been used on a variety of telescopes: our 26 in Washington, the USNO (NOFS) 61, the McDonald 82, the Mt. Wilson 100 and the twin 4 meter telescopes of KPNO and CTIO. While these instruments have each yielded many observations, they have been ... |
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| Know the Star, Know the Planet. 2. Speckle Interferometry of Exoplanet Host Stars |
Nov 2011 |
7 pages |
| Authors:
Brian D Mason; William I Hartkopf; Deepak Raghavan; John P Subasavage; Jr Roberts Lewis C; Nils H Turner; Theo A ten Brummelaar; NAVAL OBSERVATORY WASHINGTON DC
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| A study of the host stars to exoplanets is important for understanding their environment. To that end, we report new speckle observations of a sample of exoplanet host primaries. The bright exoplanet host HD 8673 (= HIP 6702) is revealed to have a companion, although at this time we cannot definitively establish the companion as physical or optical. The observing lists for planet searches and for these observations have for ... |
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| Know the Star, Know the Planet |
Nov 2011 |
8 pages |
| Authors:
Jr Roberts Lewis C; Nils H Turner; Theo A ten Brummelaar; Brian D Mason; William I Hartkopf; NAVAL OBSERVATORY WASHINGTON DC
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| The results of an adaptive optics survey of exoplanet host stars for stellar companions are presented. We used the Advanced Electro-Optical System telescope and its adaptive optics system to collect deep images of the stars in the I band. Sixty-two exoplanet host stars were observed and fifteen multiple star systems were resolved. Of these eight are known multiples, while seven are new candidate binaries. For all binaries, we measured the ... |
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| Binary Star Orbits. 4. Orbits of 18 Southern Interferometric Pairs |
Sep 2010 |
10 pages |
| Authors:
Brian D Mason; William I Hartkopf; Andrei Tokovinin; NAVAL OBSERVATORY WASHINGTON DC
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| First orbits are presented for 3 interferometric pairs and revised solutions for 15 others, based in part on first results from a recently initiated program of speckle interferometric observations of neglected southern binaries. Eight of these systems contain additional components, with multiplicity ranging up to 6. |
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| A Survey of Stellar Families Multiplicity of Solar-Type Stars |
Sep 2010 |
44 pages |
| Authors:
Deepak Raghavan; Harold A McAlister; Todd J Henry; David W Latham; Geoffrey W Marcy; Brian D Mason; Douglas R Gies; Russel J ten White; Theo A Brummelaar; GEORGIA STATE UNIV ATLANTA CENTER FOR HIGH ANGULAR RESOLUTION ASTRONOMY
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| We present the results of a comprehensive assessment of companions to solar-type stars. A sample of 454 stars including the Sun, was selected from the Hipparcos catalog with pi 40 mas, sigma pi/pi 0.05, 0.5 less than or equal to B less than or equal to 1.0 (F6-K3), and constrained by absolute magnitude and color to exclude evolved stars. These criteria are equivalent to selecting all dwarf and subdwarf stars ... |
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| Binary Star Orbits. III. In which we Revisit the Remarkable Case of Tweedledum and Tweedledee |
14 Jun 2010 |
29 pages |
| Authors:
Brian D Mason; William I Hartkopf; Harold A McAlister; NAVAL OBSERVATORY WASHINGTON DC
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| Two of the most challenging objects for optical interferometry in the middle of the last century were the close components (FIN 332) of the wide visual binary STF2375 (= WDS 18455+0530 = HIP 92027 = ADS 11640). Each component of the wide pair was found to have subcomponents of approximately the same magnitude, position angle and separation and, hence, were designated by the tongue in cheek monikers Tweedledum and Tweedledee ... |
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| Binary Star Orbits. III. Revisting the Remarkable Case of Tweedledum and Tweedledee |
11 Jun 2010 |
13 pages |
| Authors:
Brian D Mason; William I Hartkopf; Harold A McAlister; NAVAL OBSERVATORY WASHINGTON DC
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| Two of the most challenging objects for optical interferometry in the middle of the last century were the close components of the wide visual binary STF2375. Each component of the wide pair was found to have subcomponents of approximately the same magnitude, position angle and separation and, hence, were designated by the tongue-in-cheek monikers Tweedledum and Tweedledee by the great visual interferometrist William S. Finsen in 1953. They were later ... |
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| Speckle Interferometry at the Blanco and Soar Telescopes in 2008 and 2009 |
Feb 2010 |
15 pages |
| Authors:
Andrei Tokovinin; Brian D Mason; William I Hartkopf; CERRO TOLOLO INTER-AMERICAN OBSERVATORY LA SERENA (CHILE)
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| The results of speckle interferometric measurements of binary and multiple stars conducted in 2008 and 2009 at the Blanco and SOAR 4 m telescopes in Chile are presented. A total of 1898 measurements of 1189 resolved pairs or sub-systems and 394 observations of 285 un-resolved targets are listed. We resolved for the first time 48 new pairs, 21 of which are new sub-systems in close visual multiple stars. Typical internal ... |
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| Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits |
May-2009 |
15 pages |
| Authors:
Brian D Mason; William I Hartkopf; NAVAL OBSERVATORY WASHINGTON DC
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| Results are presented for 607 speckle interferometric observations of double stars, as well as 222 measures of single stars or unresolved pairs. All data were obtained in 2006 and 2007 at the Mount Wilson Observatory, using the 2.5 m Hooker telescope. Separations range from 0.06 to 6.31, with a median of 0.34. These three observing runs concentrated on binaries in need of confirmation (mainly Hipparcos and Tycho pairs), as well ... |
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| Cool Subdwarf Investigations. II. Multiplicity |
Apr 2009 |
10 pages |
| Authors:
Wei-Chun Jao; Brian D Mason; William I Hartkopf; Todd J Henry; Stephanie N Ramos; GEORGIA STATE UNIV ATLANTA DEPT OF PHYSICS AND ASTRONOMY
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| Cool subdwarfs of types K and M are the fainter counterparts of cool main-sequence dwarfs that dominate the Galactic population. In this paper, we present the results of an optical speckle survey of 62 confirmed cool subdwarf systems within 60 pc. We have resolved two new companions and confirmed two previously known companions with separations 0.13-3. 29. After including previously known wide companions and all known spectroscopic binaries, we determine ... |
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| The High Angular Resolution Multiplicity of Massive Stars |
Feb-2009 |
21 pages |
| Authors:
Brian D Mason; William I Hartkopf; Douglas R Gies; Todd J Henry; John W Helsel; NAVAL OBSERVATORY WASHINGTON DC
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| We present the results of a speckle interferometric survey of Galactic massive stars that complements and expands upon a similar survey made over a decade ago. The speckle observations were made with the Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory 4 m telescopes and USNO speckle camera, and they are sensitive to the detection of binaries in the angular separation regime between 0.03 and 5 with relatively bright ... |
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| The Visual Orbit of the 1.1 Day Spectroscopic Binary Sigma2 Coronae Borealis From Interferometry at the Chara Array |
01 Jan 2009 |
14 pages |
| Authors:
Deepak Raghavan; Harold A McAlister; Guillermo Torres; David W Latham; Brian D Mason; Tabetha S Boyajian; Ellyn K Baines; Stephen J Williams; Theo A Brummelaar; Chris D Farrington; GEORGIA STATE UNIV ATLANTA CENTER FOR HIGH ANGULAR RESOLUTION ASTRONOMY
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| We present an updated spectroscopic orbit and a new visual orbit for the double-lined spectroscopic binary %2 Coronae Borealis (CrB) based on radial velocity measurements at the Oak Ridge Observatory in Harvard, MA and interferometer visibility measurements at the Center for High Angular Resolution Astronomy (CHARA) Array on Mount Wilson in California. sigma2 CrB is composed of two Sun-like stars of roughly equal mass in a circularized orbit with a ... |
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| Division IV/Commission 26/Working Group. Binary and Multiple System Nomenclature. Triennial report 2006-2009 |
Jan-2009 |
3 pages |
| Authors:
Brian D Mason; William I Hartkopf; Dimitri Pourbaix; Colin D Scarfe; Marion Schmitz; Andrei A Tokovinin; NAVAL OBSERVATORY WASHINGTON DC
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| The Working Group on Binary and Multiple System Nomenclature was formed within Commission 26 following Special Session 3 held during the 2003 Sydney General Assembly. Its purpose is to create the Washington Multiplicity Catalog, a comprehensive database first introduced at a multi-commission meeting at the IAU XXIV General Assembly in Manchester, 2000. Data are being compiled from the US Naval Observatory visual binary catalogs and supplemented with binary and multiple ... |
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| Densification of the Optical Reference Frame |
Jan-2009 |
4 pages |
| Authors:
Norbert Zacharias; Jean Souchay; Jose L Haro; David G Muinos Monet; Francois Mignard; Brian D Mason; Irina I Kumkova; Ralph A Gaume; Dafydd W Evans; Christine Ducourant; Thomas E Corbin; Beatrice Bucciarelli; William F Altena; Imants van Platais; Sean E Urban; NAVAL OBSERVATORY WASHINGTON DC
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| A continuation of this WG was voted for at the IAU GA 2006 in Prague. The International Celestial Reference Frame (ICRF) is defined by the positions of 212 distant quasars at radio wavelengths. The primary, optical reference frame is the Hipparcos Celestial Reference Frame (HCRF), which is the Hipparcos Catalog without astrometric problem stars (in: H. Rickman (ed.) 2001, Proceedings IAU XXIV General Assembly, Transactions IAU XXIVB (San Francisco: ASP), ... |
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| Speckle Interferometry at the U.S. Naval Observatory. XIV |
Dec 2008 |
5 pages |
| Authors:
Brian D Mason; William I Hartkopf; Gary L Wycoff; NAVAL OBSERVATORY WASHINGTON DC
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| The results of 2033 intensified CCD observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1297 mean relative positions and range in separation from 0. 54 to 58. 96, with a mean separation of 14. 99. This is the 14th in this series of ... |
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| New Frontiers in Binary Stars: Science at High Angular Resolution |
Jan 2008 |
9 pages |
| Authors:
Gail Schaefer; Tom Armstrong; Chad Bender; Michelle Creech-Eakman; Francis Fekel; Otto Franz; William Hartkopf; Donald Hutter; Brian D Mason; John Monnier; Matthew Muterspaugh; Lisa Prato; Stephen Ridgway; Michal Simon; Theo Brummelaar; Lawrence Wasserman; Ming Zhao; GEORGIA STATE UNIV ATLANTA CENTER FOR HIGH ANGULAR RESOLUTION ASTRONOMY
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| The mass of a star determines how it evolves throughout its lifetime from beginning to end. Understanding the fundamental relationships between stellar mass, luminosity, and radius over a range of metallicities from the current solar values to the extremely low metallicities representative of the early universe is essential to the study of stellar astrophysics. This requires measuring high precision masses for stars over a wide range of evolutionary stages. Such ... |
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| O Type and Other Hot Binaries: Current Statistics of the USNO Database |
01-Jan-2007 |
11 pages |
| Authors:
Brian D Mason; NAVAL OBSERVATORY WASHINGTON DC
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| The first speckle survey of O stars (Mason et al. 1998) conducted on NOAO 4-m telescopes in 1994-6 had success far in excess of our expectations. In addition to the conclusions in the multiplicity analysis, many of the new systems which were first resolved in this paper have very significant astrophysical interest. This updates the statistics from 1998 based on new results from the double star catalogs maintained at the ... |
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| Adaptive Optics Photometry and Astrometry of Binary Stars. III. A Faint Companion Search of O-Star Systems |
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13 pages |
| Authors:
Brian D Mason; Nils H Turner; Theo A Brummelaar; Lewis C Roberts; William I Hartkoff; Douglas R Gies; NAVAL OBSERVATORY WASHINGTON DC ASTROMETRY DEPT
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| We present the results of an adaptive optics survey for faint companions among Galactic O-type star systems (with V 8) using the Advanced Electro-Optical System (AEOS) 3.6 m telescope on Haleakala. We surveyed these O-star systems in the I -band, typically being able to detect a companion with a magnitude difference of deltam(sub I) < or ~ 6 in the projected separation range 0".5 < rho < 1".0, and deltam(sub ... |
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