| Imaging Disk Distortion of Be Binary System Delta Scorpii Near Periastron |
20 Sep 2012 |
19 pages |
| Authors:
X Che; J D Monnier; C Tycner; S Kraus; R T Zavala; F Baron; E Pedretti; T ten Brummelaar; H McAlister; S T Ridgway; NAVAL OBSERVATORY FLAGSTAFF AZ
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 | The highly eccentric Be binary system δ Sco reached periastron during early 2011 July, when the distance between the primary and secondary was a few times the size of the primary disk in the H band. This opened a window of opportunity to study how the gaseous disks around Be stars respond to gravitational disturbance. We first refine the binary parameters with the best orbital phase coverage data from the ... |
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| Orbit and Stellar Properties of the Young Triple V807 Tau |
10 Sep 2012 |
16 pages |
| Authors:
G H Schaefer; L Prato; M Simon; R T Zavala; NAVAL OBSERVATORY FLAGSTAFF AZ
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| We present new orbital measurements of the pre-main-sequence triple system, V807 Tau, using adaptive optics imaging at the Keck Observatory. We computed an orbit for the close pair, V807 Tau Ba--Bb, with a period of 12.312 + or - 0.058 years and a semi-major axis of 38.59 + or - 0.16 mas. By modeling the center of mass motion of the components in the close pair relative to the wide ... |
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| UCAC3 Proper Motion Survey. 2. Discovery of New Proper Motion Stars in UCAC3 with 0.40 yr-1 micro or = 0.18 yr-1 between Declinations -47 deg and 00 deg |
01 Feb 2012 |
12 pages |
| Authors:
Charlie T Finch; Norbert Zacharias; Mark R Boyd; Todd J Henry; Nigel C Hambly; NAVAL OBSERVATORY WASHINGTON DC
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| The third U.S. Naval Observatory (USNO) CCD Astrograph Catalog (UCAC3) (Zacharias et al. 2010) proper motion survey addresses the possibility that proper motion surveys using digitized scans of photographic plates might overlook some proper motion systems. The UCAC3 obtained accurate proper motions by combining CCD observations with early epoch photographic data. This survey utilizes the UCAC3 proper motions to discover new systems that have been missed in previous efforts. |
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| Lost Chevalier Pairs - A Followup |
Jan 2012 |
13 pages |
| Authors:
W I Hartkopf; NAVAL OBSERVATORY WASHINGTON DC
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| Erno Berko (2011) recently undertook the commendable effort of investigating a large number of doubles which had been discoverered by Chevalier (1908) but never confirmed. While checking over Berko's work in the course of entering his corrections into the WDS 1 , some patterns began to emerge in these corrections; this prompted an analysis of Chevalier's paper. A number of errors were found in that early work, including one significant ... |
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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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| Comparative Magnetic Minima: Characterizing Quiet Times in the Sun and Stars. Symposium of the International Astronomical Union (286th) Held in Mendoza, Argentina on October 3-7, 2011 |
Oct 2011 |
25 pages |
| Authors:
Cristina H Mandrini; David F Webb; BUENOS AIRES UNIV (ARGENTINA)
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| Solar and stellar minima represent times of low magnetic activity and simple helio/asterospheres. They are thus excellent targets for interdisciplinary, system-wide studies of the origins of stellar variability and consequent impacts on planetary systems. The recent solar minimum lasted longer and was quieter than any we have observed in the Space Age, inspiring both scientific and public interest. It also extends our knowledge of the dynamic range of solar activity ... |
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| Sky Glow from Cities: The Army Illumination Model v2 |
Sep 2011 |
48 pages |
| Authors:
Richard C Shirkey; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM
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| The increasing number of people living on earth and the corresponding increase in outdoor lighting has resulted in light pollution a brightening night sky that has obliterated the stars for much of the world s population. However, for military purposes, in particular Night Vision Goggle (NVG) users, this light can allow for detection of targets that might ordinarily not be seen. The amount of light scattered from an urban location ... |
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| Molecular and Dusty Layers of Asymptotic Giant Branch Stars Studied with the VLT Interferometer |
Sep 2011 |
6 pages |
| Authors:
Markus Wittkowski; Iva Karovicova; David A Boboltz; Eric Fossat; Michael Ireland; Keiichi Ohnaka; Michael Scholz; Francois van Wyk; Patricia Whitelock; Peter R Wood; Albert A Zijlstra; NAVAL OBSERVATORY WASHINGTON DC
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| Mass loss from asymptotic giant branch (AGB) stars is the most important driver for the evolution of low to intermediate mass stars towards planetary nebulae. It is also one of the most important sources of chemical enrichment of the interstellar medium. The mass-loss process originates in the extended atmosphere, whose structure is affected by stellar pulsations, and where molecular and dusty layers are formed. Optical interferometry resolves the extended atmospheres ... |
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| Speckle Interfermometry at the U.S. Naval Observatory. XVII |
AUG 2011 |
5 pages |
| Authors:
Brian D. Mason; William I. Hartkopf; Gary L. Wycoff; NAVAL OBSERVATORY WASHINGTON DC
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| The results of 3362 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 1970 mean relative positions and range in separation from 0. 78 to 72. 17, with amean separation of 14. 76. This is the 17th in this series of papers ... |
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| Star Tracker Attitude Estimation for an Indoor Ground-Based Spacecraft Simulator |
Aug 2011 |
20 pages |
| Authors:
Jack Tappe; Jae J Kim; Albert Jordan; Brij Agrawal; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This paper presents a study of star tracker attitude estimation algorithms and implementation on an indoor ground-based Three Axis Spacecraft Simulator (TASS). Angle, Planar Triangle, and Spherical Triangle algorithms are studied for star pattern recognition. Least squares, QUEST and TRIAD algorithms are studied for attitude determination. A star field image is suspended above TASS. The indoor laboratory environment restricts the placement of the star field to be in close proximity ... |
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| Discovery and Analysis of 21 micrometer Feature Sources in the Magellanic Clouds (Postprint) |
10 JUL 2011 |
32 pages |
| Authors:
Kevin Volk; Bruce J. Hrivnak; Mikako Matsuura; Jeronimo Bernard-Salas; Ryszard Szczerba; G. C. Sloan; Kathleen E. Kraemer; Jacco T. van Loon; F. Kemper; Paul M. Woods; Albert A. Zijlstra; Raghvendra Sahai; Margaret Meixner; Karl D. Gordon; Robert A. Gruendl; Alexander G. Tielens; Remy Indebetouw; Massimo Marengo; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
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| Spitzer Space Telescope mid-infrared spectroscopy has been obtained for 15 carbon-rich protoplanetary nebulae (PPNe) in the Large Magellanic Cloud (LMC) and for two other such stars in the Small Magellanic Cloud (SMC). Of these 17 PPNe, the unidentified 21 micrometer feature is strong in 7 spectra, weak in 2 spectra, and very weak or questionable in 4 spectra. Two of the four spectra without the 21 micrometer feature have a ... |
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| An Interferometric and Spectroscopic Analysis of the Multiple Star System HD 193322 |
JUL 2011 |
15 pages |
| Authors:
Theo A. ten Brummelaar; David P. O'Brien; Brian D. Mason; Christopher D. Farrington; Alexander W. Fullerton; Douglas R. Gies; Erika D. Grundstrom; William I. Harkopf; Rachel A. Matson; Harold A. McAlister; NAVAL OBSERVATORY WASHINGTON DC
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| The star HD 193322 is a remarkable multiple system of massive stars that lies at the heart of the cluster Collinder 419. Here we report on new spectroscopic observations and radial velocities of the narrow-lined component Ab1 which we use to determine its orbital motion around a close companion Ab2 (P = 312 days) and around a distant third star Aa (P = 35 years). We have also obtained long ... |
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| Ionizing Radiation in Earth's Atmosphere and in Space Near Earth |
MAY 2011 |
32 pages |
| Authors:
Wallace Friedberg; Kyle Copeland; FEDERAL AVIATION ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROSPACE MEDICAL INST
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| The Civil Aerospace Medical Institute of the FAA is charged with identifying health hazards in air travel and in commercial human space travel. This report addresses one of these hazards - ionizing radiation. Ionizing radiation is a subatomic particle of matter or packet of energy (photon) with sufficient energy to eject an orbital electron from an atom. Charged subatomic particles from exploding stars (supernovae) are a constant source of ionizing ... |
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| Extragalactic Fields Optimized for Adaptive Optics |
MAR 2011 |
19 pages |
| Authors:
Ivana Damjanov; Roberto G. Abraham; Karl Glazebrook; Peter McGregor; Francois Rigaut; Patrick J. McCarthy; Jarle Brinchmann; Jean-Charles Cuillandre; Yannick Mellier; Henry J. McCracken; NAVAL OBSERVATORY WASHINGTON DC
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| In this paper we present the coordinates of 67 55' x 55' patches of sky which have the rare combination of both high stellar surface density (>0.5 arcmin^{-2} with 13 |
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| Characteristics of Kepler Planetary Candidates Based on the First Data Set |
20 Feb 2011 |
21 pages |
| Authors:
William J Borucki; David G Koch; Gibor Basri; Natalie Batalha; Alan Boss; Timothy M Brown; Douglas Caldwell; Joergen Christensen-Dalsgaard; William D Cochran; Edna DeVore; NAVAL OBSERVATORY FLAGSTAFF AZ
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| In the spring of 2009, the Kepler Mission commenced high-precision photometry on nearly 156,000 stars to determine the frequency and characteristics of small exoplanets, conduct a guest observer program, and obtain asteroseismic data on a wide variety of stars. On 2010 June 15, the Kepler Mission released most of the data from the first quarter of observations. At the time of this data release, 705 stars from this first data ... |
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| Modeling Kepler Transit Light Curves as False Positives: Rejection of Blend Scenarios for Kepler-9, and Validation of Kepler-9 d, a Super-Earth-Size Planet in a Multiple System |
20 Jan 2011 |
20 pages |
| Authors:
Guillermo Torres; Francois Fressin; Natalie M Batalha; William J Borucki; Timothy M Brown; Stephen T Bryson; Lars A Buchhave; David Charbonneau; David R Ciardi; Edward W Dunham; CALIFORNIA INST OF TECHNOLOGY PASADENA CA JET PROPULSION LAB
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| Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive we describe a procedure (BLENDER) to model the photometry in terms of a blend rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose ... |
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| Establishing Alpha Oph as a Prototype Rotator: Improved Astrometric Orbit |
10 Jan 2011 |
7 pages |
| Authors:
Sasha Hinkley; John D Monnier; Ben R Oppenheimer; Jr Roberts Lewis C; Michael Ireland; Neil Zimmerman; Douglas Brenner; Ian R Parry; Frantz Martinache; Olivier Lai; CALIFORNIA INST OF TECH PASADENA
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| The nearby star alpha Oph (Ras Alhague) is a rapidly rotating A5IV star spinning at approximately 89% of its breakup velocity. This system has been imaged extensively by interferometric techniques, giving a precise geometric model of the star's oblateness and the resulting temperature variation on the stellar surface. Fortuitously, alpha Oph has a previously known stellar companion, and characterization of the orbit provides an independent, dynamically based check of both ... |
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| CCD Photometry of the Open Cluster Tombaugh 5 in the Vilnius System |
Jan 2011 |
14 pages |
| Authors:
J Zdanavicius; F J Vrba; K Zdanavicius; V Straizys; R P Boyle; NAVAL OBSERVATORY FLAGSTAFF AZ
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| We present the results of eight-color CCD photometry of 674 stars in the direction of the open cluster Tombaugh 5 in Camelopardalis. The stars are observed in the Vilnius system supplemented by the broad-band I filter the field is of 22' diameter, the limiting magnitude is V = 17.7 mag. The catalog contains the coordinates, V magnitudes, seven color indices, two-dimensional spectral types determined from photometric parameters, interstellar extinctions and ... |
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| The Extended Atmospheres of Mira Variables Probed by VLTI, VLBA, and APEX |
Jan 2011 |
7 pages |
| Authors:
M Wittkowski; D A Boboltz; C de Breuck; M Gray; E Humphreys; M Ireland; I Karovicova; K Ohnaka; A E Ruiz-Velasco; M Scholz; NAVAL OBSERVATORY WASHINGTON DC
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| We present an overview on our project to study the extended atmospheres and dust formation zones of Mira stars using coordinated observations with the Very Large Telescope Interferometer (VLTI), the Very Long Baseline Array (VLBA), and the Atacama Pathfinder Experiment (APEX). The data are interpreted using an approach of combining recent dynamic model atmospheres with a radiative transfer model of the dust shell, and combining the resulting model structure with ... |
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| Multi-Epoch Mid-Infrared Interferometric Observations of the Oxygen-rich Mira Variable Star RR Aql with the VLTI/MIDI Instrument |
Jan 2011 |
6 pages |
| Authors:
I Karovicova; M Wittkowski; D A Boboltz; E Fossat; K Ohnaka; M Scholz; NAVAL OBSERVATORY WASHINGTON DC
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| This work is part of an on-going program of multi-epoch simultaneous observations of a sample of four evolved stars - RR Aql, GX Mon, S Ori, and AH Sco - using the VLTI and VLBA facilities. Different pulsating layers and their relative positions are monitored across phases and cycles. Here, we present mid-infrared interferometric observations of the oxygen-rich Mira variable RR Aql at 13 epochs covering 4 pulsation cycles with ... |
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| Inhomogeneities in Molecular Layers of Mira Atmospheres |
Jan 2011 |
7 pages |
| Authors:
M Wittkowski; D A Boboltz; M Ireland; I Karovicova; K Ohnaka; M Scholz; F van Wyk; P Whitelock; P R Wood; A A Zijlstra; NAVAL OBSERVATORY WASHINGTON DC
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| Aims. We investigate the structure and shape of the photospheric and molecular layers of the atmospheres of four Mira variables. Methods. We obtained near-infrared K-band spectro-interferometric observations of the Mira variables R Cnc, X Hya, W Vel, and RW Vel with a spectral resolution of about 1500 using the AMBER instrument at the VLTI. We obtained concurrent JHKL photometry using the Mk II instrument at the SAAO. Results. The Mira ... |
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| Mid-Infrared Interferometric Monitoring of Evolved Stars: The Dust Shell Around the Mira Variable RR Aquilae at 13 Epochs |
Jan 2011 |
16 pages |
| Authors:
I Karovicova; M Wittkowski; D A Boboltz; E Fossat; K Ohnaka; M Scholz; NAVAL OBSERVATORY WASHINGTON DC
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| Aims: We present a unique multi-epoch infrared interferometric study of the oxygen-rich Mira variable RR Aql in comparison to radiative transfer models of the dust shell. We investigate flux and visibility spectra at 8-13 microns with the aim of better understanding the pulsation mechanism and its connection to the dust condensation sequence and mass-loss process. Methods: We obtained 13 epochs of mid-infrared interferometry with the MIDI instrument at the VLTI ... |
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| UCAC and URAT: Optical Astrometric Catalog Observing Programs |
21 Sep 2010 |
43 pages |
| Authors:
Norbert Zacharias; Ralph Gaume; NAVAL OBSERVATORY WASHINGTON DC
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| The third USNO CCD Astrograph Catalog (UCAC3) all-sky catalog was released in August 2009. The final release, UCAC4, is in preparation and will include corrections and improvements to positions and proper motions, as well as publication of intermediate data. Properties of UCAC products are presented. The USNO Robotic Astrometric Telescope (URAT) project uses the optics of the UCAC telescope with a new, wide-field camera to cover 28 square degrees per ... |
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| The Solar Neighborhood. 22. Parallax Results from the CTIOPI 0.9 m Program: Trigonometric Parallaxes of 64 Nearby Systems With 0.5 < or = mu < or = 1.0 yr-1 (SLOWMO Sample) |
SEP 2010 |
16 pages |
| Authors:
Adric R. Riedel; John P. Subasavage; Charlie T. Finch; Wei-Chun Jao; Todd J. Henry; Jennifer G. Winters; Misty A. Brown; Philip A. Ianna; Edgardo Costa; Rene A. Mendez; NAVAL OBSERVATORY WASHINGTON DC ASTROMETRY DEPT
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| We present trigonometric parallaxes of 64 stellar systems with proper motions between 0".5 yr(exp -1)and 1".0 yr(exp -1) from the ongoing Research Consortium On Nearby Stars parallax program at the Cerro Tololo Inter-American Observatory. All of the systems are south of decl. = +30, and 58 had no previous trigonometric parallaxes. In addition to parallaxes for the systems, we present proper motions, Johnson-Kron-Cousins VRI photometry, variability measurements, and spectral types. ... |
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| Size and Albedo of Kuiper Belt Object 55636 from a Stellar Occultation |
JUN 2010 |
5 pages |
| Authors:
J. L. Elliot; M. J. Person; C. A. Zuluaga; A. S. Bosh; E. R. Adams; T. C. Brothers; A. A. Gulbis; S. E. Levine; M. Lockhart; A. M. Zangari; NAVAL OBSERVATORY FLAGSTAFF AZ
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| The Kuiper belt is a collection of small bodies (Kuiper belt objects, KBOs) that lie beyond the orbit of Neptune and which are believed to have formed contemporaneously with the planets. Their small size and great distance make them difficult to study. KBO 55636 (2002 TX300) is a member of the water-ice-rich Haumea KBO collisional family. The Haumea family are among the most highly reflective objects in the Solar System. ... |
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| Visitors from the Halo: 11 Gyr Old White Dwarfs in the Solar Neighborhood |
20 MAY 2010 |
6 pages |
| Authors:
Mukremin Kilic; Jeffrey A. Munn; Kurtis A. Williams; P. W. Kowalski; Ted von Hippel; Hugh C. Harris; Elizabeth J. Jeffery; Steven DeGennaro; Warren R. Brown; B. McLeod; NAVAL OBSERVATORY FLAGSTAFF AZ
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| We report the discovery of three nearby old halo white dwarf (WD) candidates in the Sloan Digital Sky Survey (SDSS), including two stars in a common proper motion binary system. These candidates are selected from our 2800 deg2 proper motion survey on the Bok and U.S. Naval Observatory Flagstaff Station 1.3m telescopes, and they display proper motions of 0".4-0".5 yr(exp -1). Follow-up MMT spectroscopy and near-infrared photometry demonstrate that all ... |
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| Selection, Prioritization, and Characteristics of Kepler Target Stars |
20 Apr 2010 |
7 pages |
| Authors:
Natalie M Batalha; William J Borucki; David G Koch; Stephen T Bryson; Michael R Hass; Timothy M Brown; Douglas A Caldwell; Jennifer R Hall; Ronald L ; David W Latham; NAVAL OBSERVATORY FLAGSTAFF AZ
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| The Kepler Mission began its 3.5 year photometric monitoring campaign in 2009 May on a select group of approximately 150,000 stars. The stars were chosen from the approximately half million in the field of view that are brighter than 16th magnitude. The selection criteria are quantitative metrics designed to optimize the scientific yield of the mission with regard to the detection of Earth-size planets in the habitable zone. This yields ... |
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| Kepler Mission Design, Realized Photometric Performance, and Early Science |
20 Apr 2010 |
9 pages |
| Authors:
David G Koch; William J Borucki; Gibor Basri; Natalie M Batalha; Timothy M Brown; Douglas Caldwell; Joergen Christensen-Dalsgaard; William D Cochran; Edna DeVore; Edward W Dunham; NAVAL OBSERVATORY FLAGSTAFF AZ
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| The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in the habitable zone of solar-like stars using the transit photometry method. Results from just 43 days of data along with ground-based follow-up observations have identified five new transiting planets with measurements of their masses, radii, and orbital periods. Many aspects of stellar astrophysics also benefit from the unique, precise, extended, and ... |
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| Kepler-4b: A Hot Neptune-Like Planet of a G0 Star Near Main-Sequence Turnoff |
20 Apr 2010 |
6 pages |
| Authors:
William J Borucki; David G Koch; Timothy M Brown; Gibor Basri; Natalie M Batalha; Douglas A Caldwell; William D Cochran; Edward W Dunham; III Gautier Thomas N; John C Geary; Ronald L Gilliland; Steve B Howell; Jon M Jenkins; David W Latham; Jack J Lissauer; Geoffrey W Marcy; David Monet; Jason F Rowe; Dimitar Sasselov; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| Early time-series photometry from NASA's Kepler spacecraft has revealed a planet transiting the star we term Kepler-4, at R.A. = 19h02m27.s68, declination = +50 deg 08 min 08 sec.7. The planet has an orbital period of 3.213 days and shows transits with a relative depth of 0.87 x 10(exp -3) and a duration of about 3.95 hr. Radial velocity (RV) measurements from the Keck High Resolution Echelle Spectrometer show a ... |
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| Kepler-6b: A Transiting Hot Jupiter Orbiting a Metal-Rich Star |
20 Apr 2010 |
5 pages |
| Authors:
Edward W Dunham; William J Borucki; David G Koch; Natalie M Batalha; Lars A Buchhave; Timothy M Brown; Douglas A Caldwell; William D Cochran; Michael Endl; Debra Fischer; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| The Kepler Mission was launched on 2009 March 6, to undertake a search for Earth-size planets orbiting in the habitable zones of stars similar to the Sun. Kepler uses the transit photometry approach for this task (Borucki et al. 2010a). Kepler s commissioning process went very well and the system provides data of exceptional photometric quality (Koch et al. 2010a). Indeed, the final commissioning data, 9.7 days of science-like observations ... |
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| Kepler Observations of Transiting Hot Compact Objects |
20 Apr 2010 |
6 pages |
| Authors:
Jason F Rowe; William J Borucki; David Koch; Steve B Howell; Gibor Basri; Natalie Batalha; Timothy M Brown; Douglas Caldwell; William D Cochran; Edward Dunham; David G Monet; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| Kepler photometry has revealed two unusual transiting companions: one orbiting an early A-star and the other orbiting a late B-star. In both cases, the occultation of the companion is deeper than the transit. The occultation and transit with follow-up optical spectroscopy reveal a 9400 K early A-star, KOI-74 (KIC 6889235), with a companion in a 5.2 day orbit with a radius of 0.08 solar radius and a 10,000 K late ... |
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| Kepler Planet-Detection Mission: Introduction and First Results |
19 Feb 2010 |
6 pages |
| Authors:
William J Borucki; David Koch; Gibor Basri; Natalie Batalha; Timothy Brown; Douglas Caldwell; John Caldwell; Joergen Christensen-Dalsgaard; William D Cochran; Edna DeVore; Edward W Dunham; Andrea K Dupree; III Gautier Thomas N; John C Geary; Ronald Gilliland; Alan Gould; Steve B Howell; Jon M Jenkins; Yoji Kondo; David W Latham; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet's surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 ... |
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| Achieving Milli-Arcsecond Residual Astrometric Error for the JMAPS Mission |
2010 |
7 pages |
| Authors:
Gregory S. Hennessy; Benjamin F. Lane; Dan Veilette; Christopher Dieck; NAVAL OBSERVATORY WASHINGTON DC
|
| The Joint Milliarcsecond Pathfinder Survey (JMAPS) is a small, space-based, all-sky, visible wavelength astrometric and photometric survey mission for 0th through 14th I-band magnitude stars with a planned 2013 launch. The primary objective of the JMAPS mission is the generation of an astrometric star catalog with 1 milliarcsecond (mas) positional accuracy or better, and photometry to the 1% accuracy level or better at 1st to 12th mag. Achieving this level ... |
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| Speckle Interferometry at Mount Wilson Observatory: Observations Obtained in 2006-2007 and 35 New Orbits |
May-2009 |
15 pages |
| Authors:
William I Hartkopf; Brian D Mason; NAVAL OBSERVATORY WASHINGTON DC
|
| 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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| 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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| CO Fundamental Emission from V836 Tauri |
10-Nov-2008 |
13 pages |
| Authors:
Joan R Najita; Nathan Crockett; John S Carr; NATIONAL OPTICAL ASTRONOMY OBSERVATORIES TUCSON AZ
|
| We present high-resolution 4.7 micron CO fundamental spectroscopy of V836 Tau, a young star with properties that are between those of classical and weak T Tauri stars and which may be dissipating its circumstellar disk. We find that the CO line profiles of V836 Tau are unusual in that they are markedly double-peaked, even after correcting for stellar photospheric absorption in the spectrum. This suggests that the CO emission arises ... |
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| Speckle Interferometry at the USNO Flagstaff Station: Observations Obtained in 2003-2004 and 17 New Orbits |
APR 2008 |
10 pages |
| Authors:
William I. Hartkopf; Brian D. Mason; Theodore J. Rafferty; NAVAL OBSERVATORY WASHINGTON DC
|
| Results are presented for 353 speckle interferometric observations of double stars, obtained in 2003 and 2004 at the USNO Flagstaff Station using the 1.55 m Kaj Strand Astrometric Reflector. Separations range from 0".12 to 7".42, with a median of 0".42. These two observing runs concentrated on systems in need of improved orbital elements, and new solutions have been determined for 17 systems as a result. |
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| The Sixth Data Release of the Sloan Digital Sky Survey |
APR 2008 |
18 pages |
| Authors:
Jennifer K. Adelman-McCarthy; Marcel A. Agueros; Sahar S. Allam; Carlos A. Prieto; Kurt S. Anderson; Scott F. Anderson; James Annis; Neta A. Bahcall; C. A. Bailer-Jones; Ivan K. Baldry; FERMI NATIONAL ACCELERATOR LAB BATAVIA IL
|
| This paper describes the Sixth Data Release of the Sloan Digital Sky Survey. With this data release, the imaging of the northern Galactic cap is now complete. The survey contains images and parameters of roughly 287 million objects over 9583 deg2, including scans over a large range of Galactic latitudes and longitudes. The survey also includes 1.27 million spectra of stars, galaxies, quasars, and blank sky (for sky subtraction) selected ... |
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| Discovery of Planetary Systems With SIM |
01-Jan-2008 |
5 pages |
| Authors:
Geoffrey W Marcy; Paul R Butler; Sabine Frink; Debra Fischer; Ben Oppenheimer; David G Monet; Andreas Quirrenbach; Jeffrey D Scargle; NAVAL OBSERVATORY WASHINGTON DC
|
| We are witnessing the birth of a new observational science: the discovery and characterization of extrasolar planetary systems. In the past five years, over 70 extrasolar planets have been discovered by precision Doppler surveys, most by members of this SIM team. We are using the data base of information gleaned from our Doppler survey to choose the best targets for a new SIM planet search. In the same way that ... |
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| Large Synoptic Survey Telescope: From Science Drivers to Reference Design |
Jan-2008 |
14 pages |
| Authors:
Z Ivezic; S M Kahn; J P Kantor; V Krabbendam; R H Lupton; D G Monet; P A Pinto; A Saha; T L Schalk; R L Jones; S H Jacoby; T Axelrod; W N Brandt; D L Burke; C F Claver; A Connolly; K H Cook; P Gee; D K Gillmore; D P Schneider; WASHINGTON UNIV SEATTLE DEPT OF ASTRONOMY
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| In the history of astronomy, major advances have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time ... |
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| Autonomous Sensing of Layered Structures in Hawaiian Waters |
Jan-2008 |
6 pages |
| Authors:
Margaret A McManus; HAWAII UNIV AT MANOA HONOLULU DEPT OF OCEANOGRAPHY
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| Our long-term goals are (1) to determine the spatial and temporal scales of thin layers, (2) to identify the processes responsible for the formation, maintenance and dissipation of vertically thin layers, and (3) to develop the capability to predict thin layer formation and presence in the sea. The central focus of our research is to investigate: the spatial and temporal scales of thin layers, the relationship between physical processes (from ... |
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| Two Stellar Components in the Halo of the Milky Way |
13 DEC 2007 |
8 pages |
| Authors:
Daniela Carollo; Timothy C. Beers; Young-Sun Lee; Masashi Chiba; John E. Norris; Ronald Wilhelm; Thirupathi Sivarani; Brian Marsteller; Jeffrey A. Munn; Coryn A. Bailer-Jones; NAVAL OBSERVATORY FLAGSTAFF AZ
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| The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, and this information can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for its dichotomy has slowly emerged in recent years from inspection of small samples of halo objects. Here we show that the halo ... |
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| Speckle Interferometry at the US Naval Observatory. XIII |
OCT 2007 |
9 pages |
| Authors:
Brian D. Mason; William I. Hartkopf; Gary L. Wycoff; Gary Wieder; NAVAL OBSERVATORY WASHINGTON DC
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| The results of 1424 speckle interferometric observations of double stars, made with the 26 inch (66 cm) refractor of the US Naval Observatory, are presented. Each speckle interferometric observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1053 mean relative positions and range in separation from 0.360" to 61.92", with a median separation of 10.31". This is the 13th in a series ... |
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| The Fifth Data Release of the Sloan Digital Sky Survey |
OCT 2007 |
12 pages |
| Authors:
Gregory S. Hennessy; NAVAL OBSERVATORY WASHINGTON DC
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| This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through 2005 June and represents the completion of the SDSS-I project (whose successor, SDSS-II, will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 deg squared and 1,048,960 spectra of galaxies, quasars, and stars selected from 5713 deg squared of that imaging ... |
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| CallFUSE Version 3: A Data Reduction Pipeline for the Far Ultraviolet Spectroscopic Explorer |
MAY 2007 |
30 pages |
| Authors:
W. V. Dixon; D. J. Sahnow; P. E. Barrett; T. Civeit; J. Dupuis; A. W. Fullerton; B. Godard; J. Hsu; M. E. Kaiser; J. W. Kruk; JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF PHYSICS AND ASTRONOMY
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| Since its launch in 1999, the Far Ultraviolet Spectroscopic Explorer (FUSE) has made over 4900 observations of some 2500 individual targets. The data are reduced by the principal investigator team at the Johns Hopkins University and archived at the Multimission Archive at STScI (MAST). The data reduction software package, called CalFUSE, has evolved considerably over the lifetime of the mission. The entire FUSE data set has recently been reprocessed with ... |
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| Gas at the Inner Disk Edge |
MAY 2007 |
13 pages |
| Authors:
John S. Carr; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
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| Infrared molecular spectroscopy is a key tool for the observation of gas in the innermost region of disks around T Tauri stars. In this contribution, we examine how infrared spectroscopy of CO can be used to study the inner truncation region of disks around T Tauri stars. The inferred inner gas radii for T Tauri star disks are compared to the inner dust radii of disks, to the expectations of ... |
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| Trigonometric Parallaxes of Central Stars of Planetary Nebulae |
FEB 2007 |
9 pages |
| Authors:
Hugh C. Harris; Conard C. Dahn; Blaise Canzian; Harry H. Guetter; S. K. Leggett; Stephen E. Levine; Christian B. Luginbuhl; Alice K. Monet; David G. Monet; Jeffrey R. Pier; NAVAL OBSERVATORY FLAGSTAFF AZ
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| Trigonometric parallaxes of 16 nearby planetary nebulae are presented, including reduced errors for seven objects with previous initial results and results for six new objects. The median error in the parallax is 0.42 mas, and 12 nebulae have parallax errors of less than 20%. The parallax for PHL 932 is found here to be smaller than was measured by Hipparcos, and this peculiar object is discussed. Comparisons are made with ... |
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| Initial Results From the USNO Dispersed Fourier Transform Spectrograph |
25 JAN 2007 |
19 pages |
| Authors:
Arsen R. Hajian; Bradford B. Behr; Andrew T. Cenko; Robert P. Olling; David Mozurkewich; J. T. Armstrong; Brian Pohl; Sevan Petrossian; Kevin H. Knuth; Robert B. Hindsley; NAVAL OBSERVATORY WASHINGTON DC
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| We have designed and constructed a dispersed Fourier transform spectrometer (dFTS), consisting of a conventional FTS followed by a grating spectrometer. By combining these two devices,we negate a substantial fraction of the sensitivity disadvantage of a conventional FTS for high-resolution, broadband, optical spectroscopy, while preserving many of the advantages inherent to interferometric spectrometers. In addition, we have implemented a simple and inexpensive laser metrology system, which enables very precise calibration ... |
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| Habitable Planets for Man |
2007 |
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| Authors:
Stephen H. Dole; RAND CORP SANTA MONICA CA
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 | "Habitable Planets for Man" examines and estimates the probabilities of finding planets habitable to human beings, where they might be found, and the number there may be in our own galaxy. The author presents in detail the characteristics of a planet that can provide an acceptable environment for humankind, itemizes the stars nearest the earth most likely to possess habitable planets, and discusses how to search for habitable planets. Interestingly ... |
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