scholarly journals Detection of Double Stars with the Two-Color Refractometer

1983 ◽  
Vol 62 ◽  
pp. 28-35 ◽  
Author(s):  
James W. Christy ◽  
Dennis D. Wellnitz ◽  
Douglas G. Currie
Keyword(s):  
Position Angle ◽  
Angular Distance ◽  
Double Star ◽  
Measured Quantity ◽  
University Of Maryland ◽  
Additional Information ◽  
Double Stars ◽  
Color Differences ◽  
Nearby Stars ◽  
The University

AbstractAttempts to detect double stars are being made with the Two-Color Refractometer (TCR). The refractometer is an instrument developed by the Quantum Electronics Group of the University of Maryland to measure atmospheric refraction.During check-out observations using the U.S. Naval Observatory’s (USNO’s) 24“ reflecting telescope, the refractometer is being used to detect the astrometric separation of the ultraviolet and red photocenters of the combined light from a double star, differentially referenced to nearby stars. The refractometer contains two dispersive wedges which null the incoming dispersion; the positions of the wedges then provide a measure of the dispersion of the incoming light. The angular part of this measure immediately gives the position angle of the double. The angular distance between the two components of the pair is a combined function of the measured quantity and of the magnitude and color differences of the components of the double star, and is therefore obtainable only with additional information.

scholarly journals The Discovery of Double Stars at Occultations

1983 ◽  
Vol 62 ◽  
pp. 63-72 ◽  
Author(s):  
David S. Evans
Keyword(s):  
Position Angle ◽  
Visual Observation ◽  
Double Star ◽  
Double Stars ◽  
Photoelectric Observations ◽  
Vector Separation ◽  
Successful Observation

When systematic photoelectric observations of occultations were started some dozen years ago it was realised that they yielded a significant crop of double star discoveries and observations. The limitations of the method were well recognised: only about ten percent of the area of the sky would ever be available and one could not choose which stars to be observed. Moreover the data obtained from a successful observation of a double star are less comprehensive than the normal visual observation. The result is the vector separation or the true separation projected along a line perpendicular to the actual lunar limb, that is the position angle of the point of occultation modified by the slope of the limb at that point.

scholarly journals Systematic Errors in Double Star Observations

1992 ◽  
Vol 135 ◽  
pp. 311-313 ◽  
Author(s):  
Geoffrey G. Douglass ◽  
Charles E. Worley
Keyword(s):  
Root Mean Square ◽  
Proximity Effect ◽  
Position Angle ◽  
Systematic Errors ◽  
Double Star ◽  
Mean Square ◽  
Double Stars ◽  
Visual Double Stars ◽  
Systematic Effects

AbstractWe have examined the visual and speckle observations of visual double stars made by 31 experienced observers in order to evaluate possible systematic errors in these series. Using 57 “definitive” orbits, we find no appreciable errors in position angle. We do find systematic effects in separation for some observers, and, in particular, a “proximity” effect for measurements of pairs closer than 0″.5.Root-mean-square residuals are:

scholarly journals Occultation by (22) Kalliope and its satellite Linus

2007 ◽  
Vol 3 (S248) ◽  
pp. 130-131 ◽  
Author(s):  
M. Sôma ◽  
T. Hayamizu ◽  
K. Miyashita ◽  
T. Setoguchi ◽  
T. Hirose
Keyword(s):  
Major Axis ◽  
Position Angle ◽  
Angular Distance ◽  
Double Star

AbstractThe occultation of a 9.1 magnitude star by asteroid (22) Kalliope and its satellite Linus was successfully observed in Japan in 2006 November 7.826 UT. This was the first definite observation of an occultation of a satellite of an asteroid that was discovered previously by other means. As a result the position of the satellite relative to Kalliope was obtained to be d = 0.246 ± 0.011 (arcsec), and P = 313.8 ± 2.7 (deg), where d is the angular distance and P is the position angle. The derived size for Kalliope is (209 ± 40)km × (136 ± 26)km (with the major axis in position angle of (8 ± 17) deg), and that for Linus is (33 ± 3) km. From the observations, the occulted star is also found to be a close double star whose separation is about 0.7 mas in position angle of about 300 deg, and the magnitudes of the components are found to be almost the same (~9.9 mag).

scholarly journals Double Star Astrometry with the Hipparcos Data

1995 ◽  
Vol 166 ◽  
pp. 69-76
Author(s):  
F. Mignard
Keyword(s):  
Position Angle ◽  
Double Star ◽  
Recognition Procedure ◽  
Double Stars ◽  
Multiple Stars ◽  
Relative Coordinates ◽  
Double And Multiple Stars

As we approach the final processing of the observations carried out by HIPPARCOS, in particular for the double and multiple stars, it is possible to provide reliable statistics on the number of such objects detected and on the quality of the relative and absolute astrometry and photometry. About 24 000 stars have been recognized as non-single, including 11 000 already known as double and multiple before the mission and 13000 discovered by Hipparcos. Also, a subset of 16 000 stars among the 24 000 have been successfully solved for their relative coordinates (position angle and separation) with an accuracy in the range of 3 to 30 mas, including 7000 new double stars. I outline in this paper the principle of the internal recognition procedure and present some statistics on the solution.

scholarly journals HIPPARCOS First Results in the Double Star Processing by the FAST Consortium

1992 ◽  
Vol 135 ◽  
pp. 403-411
Author(s):  
F. Mignard ◽  
M. Badiali ◽  
P.L. Bernacca ◽  
H. Bernstein ◽  
D. Cardini ◽  
...  
Keyword(s):  
Position Angle ◽  
Double Star ◽  
Double Stars ◽  
Multiple Stars ◽  
Relative Coordinates ◽  
First Results ◽  
Double And Multiple Stars ◽  
Quantitative Results ◽  
One Year

AbstractAfter the processing of one year of observations carried out by HIPPARCOS it is possible to provide quantitative results as to the number of new double and multiple stars to be detected and the real capacity of this mission to perform relative astrometry on double stars. We present and discuss the methods developed to this end and include the first results concerning the detection statistics and the determination of separation and position angle for double stars. About 16,000 stars have been recognized as non-single, including 9,000 already known as double and mutliple before the mission. Also, a subset of 10,500 stars have been successfully solved for their relative coordinates with an accuracy in the range of 3 to 10 mas.

scholarly journals First speckle interferometric measurements of binary stars at the Observatorio Astrofísico Guillermo Haro

2020 ◽  
Vol 495 (1) ◽  
pp. 806-815 ◽  
Author(s):  
C A Guerrero ◽  
F F Rosales-Ortega ◽  
G Escobedo ◽  
J Martínez ◽  
E Castillo ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Binary Stars ◽  
Position Angle ◽  
Double Star ◽  
Fast Imaging ◽  
Star Catalog ◽  
Double Stars ◽  
New Instrument ◽  
Imaging Camera ◽  
Magnitude Difference

ABSTRACT In this paper, we present the first multiband speckle interferometric measurements of binary stars performed using the 2.1 m telescope of the Observatorio Astrofísico Guillermo Haro, Cananea, Sonora, México. We describe here FICCO: Fast Imaging Camera for Cananea Observatory, a new instrument developed to perform speckle observations from the Northern Hemisphere. We tested this new instrument with objects from the Washington Double Star Catalog, that were observed during three runs allocated in 2019. We report 480 astrometric measurements of 138 pairs, with angular separations ranging from 0.06 to 5.76 arcsec, including 347 measurements with separations smaller than 1 arcsec. We estimated a mean error in separation of 14 mas, 1.6° in position angle, and 0.45 mag for the magnitude difference. We confirmed 12 double stars discovered by Hipparcos. Finally, we present a correction to four previously published orbital solutions of visual binaries.

Production of New and Revised A.A.V.S.O. Charts

1979 ◽  
Vol 46 ◽  
pp. 368
Author(s):  
Clinton B. Ford
Keyword(s):  
Variable Star ◽  
Standard Form ◽  
Original Data ◽  
University Of Pennsylvania ◽  
Standard Format ◽  
Additional Information ◽  
The Gift ◽  
The University

A “new charts program” for the Americal Association of Variable Star Observers was instigated in 1966 via the gift to the Association of the complete variable star observing records, charts, photographs, etc. of the late Prof. Charles P. Olivier of the University of Pennsylvania (USA). Adequate material covering about 60 variables, not previously charted by the AAVSO, was included in this original data, and was suitably charted in reproducible standard format.Since 1966, much additional information has been assembled from other sources, three Catalogs have been issued which list the new or revised charts produced, and which specify how copies of same may be obtained. The latest such Catalog is dated June 1978, and lists 670 different charts covering a total of 611 variables none of which was charted in reproducible standard form previous to 1966.

scholarly journals SUSI’s Potential for Double Star Research

1992 ◽  
Vol 135 ◽  
pp. 521-526
Author(s):  
John Davis
Keyword(s):  
Angular Resolution ◽  
Double Star ◽  
Double Stars ◽  
Stellar Interferometer ◽  
New Instrument

AbstractThe Sydney University Stellar Interferometer (SUSI) is currently undergoing commissioning and will soon commence its astronomical program in which observations of double stars will form a major component. With its 640-m long North–South array of input siderostats, the new instrument will have unprecedented angular resolution.

scholarly journals The McDonaldization of Academic Libraries?

2015 ◽  
Vol 76 (3) ◽  
pp. 339-352 ◽  
Author(s):  
Brian Quinn
Keyword(s):  
Academic Libraries ◽  
Fast Food ◽  
Food Industry ◽  
Fast Food Industry ◽  
University Of Maryland ◽  
The University

George Ritzer, a sociologist at the University of Maryland, has proposed an influential thesis that suggests that many aspects of the fast food industry are making their way into other areas of society. This article explores whether his thesis, known as the McDonaldization thesis, is applicable to academic libraries. Specifically, it seeks to determine to what extent academic libraries may be considered McDonaldized, and if so, what effect McDonaldization may be having on them. It also investigates some possible alternatives to McDonaldization, and their implications for academic libraries.

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