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Magnitude differences obtained from speckle imaging are used in combination with other data in the literature to place the components of binary star systems on the H-R diagram. Isochrones are compared with the positions obtained, and a best-fit isochrone is determined for each system, yielding both masses of the components as well as an age range consistent with the system parameters. Seventeen systems are studied, 12 of which were observed with the 0.6 m Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and six of which were observed with the WIYN 3.5 m Telescope (The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories) at Kitt Peak. One system was observed from both sites. In comparing photometric masses to mass information from orbit determinations, we find that the photometric masses agree very well with the dynamical masses, and are generally more precise. For three systems, no dynamical masses exist at present, and therefore the photometrically determined values are the first mass estimates derived for these components.

First results of a new speckle imaging system, the Differential Speckle Survey Instrument, are reported. The instrument is designed to take speckle data in two filters simultaneously with two independent CCD imagers. This feature results in three advantages over other speckle cameras: (1) twice as many frames can be obtained in the same observation time which can increase the signal-to-noise ratio for astrometric measurements, (2) component colors can be derived from a single observation, and (3) the two colors give substantial leverage over atmospheric dispersion, allowing for subdiffraction-limited separations to be measured reliably. Fifty-four observations are reported from the first use of the instrument at the Wisconsin-Indiana-Yale-NOAO 3.5 m Telescope9The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories. in 2008 September, including seven components resolved for the first time. These observations are used to judge the basic capabilities of the instrument.

A total of 1067 speckle observations of 345 binary stars are presented. Of these, 161 are double stars first resolved by Hipparcos, 17 are resolved for the first time in the observations presented here, and 21 are stars previously discovered by our program and reported in earlier papers in the series. In 947 cases, a magnitude difference is reported along with the relative astrometry. When comparing to systems with very well-known orbits, we find that the root mean square (rms) deviation in separation residuals is 2.81 ± 0.28 mas, and the rms deviation in position angle residuals is 0.88 ± 0.07°. The magnitude difference measures show no significant deviation from Hipparcos photometry, and have average standard deviation of approximately 0.10 mag as judged from repeat observations. Five important systems discovered by Hipparcos are discussed.

We describe a high-precision, deep (to V ~ 19-21) absolute proper-motion survey that samples ~50 lines of sight in the Kapteyn Selected Areas along declination zones -15, 0 and 15 degrees. In many fields the astrometric baseline reaches nearly a century. We demonstrate that these data provide typical per star precisions between ~ 1 and 3 mas/yr to the above magnitude limits, with the absolute reference frame established by numerous extragalactic sources in each survey field. Combined with existing and ongoing photometric and radial velocity surveys in these fields, these astrometric data will enable, among other things, accurate, detailed dynamical modeling of satellite interactions with our Galaxy. In this contribution we describe the astrometric part of our survey and show preliminary results along the trailing tail of the Sagittarius dwarf galaxy, and in the Monoceros ring region., Accepter for publication in the Astronomical Journal

Position angle and separation measures of 482 primarily southern binary stars are presented. These were obtained from speckle observations taken at the Carlos U. Cesco Observatory, El Leoncito, Argentina, using a multianode microchannel array detector during the period 1994 July to 1996 July. When comparing our measures to the ephemeris predictions in the case of objects with well-determined orbits, we find that our measures have a precision of approximately 13 mas per observation in separation and 075/ρ in position angle, where ρ is the separation in arcseconds. We briefly discuss the photometric properties of the data and highlight four southern binaries of particular interest that emerge from the list presented.

An analysis of 15 speckle observations taken at the Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and 6 speckle observations taken at the WIYN Telescope at Kitt Peak National Observatory indicates that it is possible to characterize the separations, position angles, and magnitude differences of binary stars down to at least one quarter of the diffraction limit with CCD-based speckle imaging. This is made possible by the fact that CCD-based speckle imaging permits the retrieval of reliable photometric information from speckle data, and therefore the elongation of the speckles due to a blended companion may be reliably measured. When observations in two colors are obtained, atmospheric dispersion, which also affects the speckle shape, can be distinguished from binarity in a large number of cases. A regimen for observing sub-diffraction-limited speckle binaries is proposed that could lead to efficient surveys of small-separation binary stars.

Five hundred seventy-six magnitude difference measures are presented for 260 binary stars. These measures are derived from CCD-based speckle observations taken at the WIYN 3.5 m telescope at Kitt Peak National Observatory during the period 1997–2000. Separations of the systems range from over 1'' down to near the diffraction limit of the telescope. A study of multiple measures of the same targets indicates that the measures have a typical uncertainty of better than 0.13 mag per 2 minute observation, and that multiple observations can be averaged to arrive at smaller uncertainties. Results presented here are also compared, insofar as it is possible, with measures in the Hipparcos Catalogue and to previous studies using adaptive optics. No major systematic errors were identified.

Spectrophotometric data have been obtained with the 2dF spectrograph at Cerro Tololo Inter-American Observatory and with Hydra at the WIYN telescope for nearly 2000 A, F, and G stars toward the south Galactic pole. Using 1305 radial velocities, 2311 uvbyHβ photometric measurements, and 1621 Yale–San Juan SPM (Southern Proper Motion) absolute proper motions, peculiar velocities were derived to determine the galactic gravitational force K(z) perpendicular to the Galactic plane, first described by Oort (published in 1932). Our results in local volume density, as derived from early-type stars (A0–F5) and giants, support Bahcall's ρ = 0.1 M⊙ pc-3, implying that dark matter exists in the galactic disk. Our result for the total surface density derived using late-type stars (G1 and later) is equal to 34 M⊙ pc-2, about 30% smaller than 46 ± 9 M⊙ pc-2 computed by Kuijken & Gilmore, but greater than 23 M⊙ pc-2 listed for the extended halo mass for z < 1.1 kpc (Cox 1999). The derived behavior of K(z) versus distance from the Galactic plane shows a well-known peak at about 400 pc. A second peak at about 1100 pc exhibited by dwarf main-sequence stars, but not for the giants, suggests that this second peak is likely due to a thick-disk population of metal-poor objects.

We have measured the absolute proper motions of four low-latitude, inner-Galaxy globular clusters. These clusters are: NGC 6266 (M62), NGC 6304, NGC 6316 and NGC 6723. The proper motions are on the Hipparcos system, as no background extragalactic objects are found in these high-extinction regions. The proper-motion uncertainties range between 0.3 and 0.6 mas/yr. We discuss the kinematics of these clusters and of three additional bulge clusters -- NGC 6522, NGC 6528 and NFC 6553 -- whose proper motions with respect to bulge stars had been determined previously. We find that all of the clusters have velocities that confine them to the bulge region. Of the three metal poor clusters ([Fe/H] < -1.0), NGC 6522, and NGC 6723 have kinematics consistent with halo membership. The third cluster, NGC 6266 however, appears to belong to a rotationally-supported system. Of the four metal rich clusters ([Fe/H] >= -1.0), NGC 6304 and NGC 6553 also have kinematics consistent with membership to a rotationally-supported system. NGC 6528 has kinematics, metallicity and mass that argue in favor of a genuine Milky-Way bar cluster. NGC 6316's kinematics indicate membership to a hotter system than the bar., 4 figures, 5 tables; accepted for publication in AJ

Two hundred thirty nearby main-sequence stars with spectral types in the range of A to G have been observed by way of speckle interferometry using the WIYN 3.5 m telescope at Kitt Peak, Arizona. The stars had no previous mention of duplicity in the literature. Of those observed, 14 showed clear evidence of a companion, and 63 were classified as suspected nonsingle based on a power spectrum analysis. The remaining stars discussed show no evidence of duplicity to the limit of the detection system in high-quality observations.

The field of direct imaging is experiencing a considerable growth in the number of available CCD mosaic imagers, especially on large telescopes. To fully exploit the astrometric potential of these imaging devices, we develop a technique, utilizing an astrometric standard, for precision transformation of pixel coordinates into a global coordinate system. We have constructed a new astrometric standard set of 1863 stars in the field of NGC 188 to derive the CCD chip constants for the NOAO CCD Mosaic Imager. The multiple-epoch data on the Mosaic's metrics indicate that this CCD mosaic device may have experienced a one-time nonelastic expansion. We also present a new determination of the pixel scale and the optical field angle distortion constants for the KPNO Mayall 4 m telescope prime focus field corrector. To establish a reliable history of the CCD mosaic imager metrics for current and potential future astrometric applications, we recommend obtaining astrometric calibrations for CCD mosaic imagers on a regular basis. Apart from mechanical positioning of the CCD mosaic camera on the telescope, noticeable changes in the thermal environment of CCD mosaic chips should also prompt new astrometric calibrations. It is shown that, following all precautions, the NOAO CCD Mosaic Imager can produce excellent astrometric results on the Mayall 4 m telescope.

Five hundred twelve relative astrometry measures are presented for 253 double stars, including 53 double stars discovered by Hipparcos. In 15 cases, relative astrometry is reported for the first time for newly confirmed pairs. In addition, 20 high-quality nondetections of companions are reported for stars suspected of being nonsingle by Hipparcos. Observations were taken using a fast-readout CCD camera system at the WIYN 3.5 m telescope at Kitt Peak, Arizona. In comparing these measures with ephemeris predictions for binary stars with very well known orbits, we find that the measurement precision is better than 3 mas in separation and 1° in position angle per individual observation. Measurement precision and detection capabilities are fully discussed, and confirmed orbital motion is reported in four cases of the Hipparcos double star discoveries.

Relative astrometry is presented for 198 observations of 160 double stars. The data were obtained at the 2.15 m telescope at the Complejo Astronomico El Leoncito (Argentina) with a multianode microchannel array (MAMA) detector system. Five high-quality nondetections are also reported. When judged against ephemeris positions for binaries with very well determined orbits, the separation residuals exhibit a root mean square deviation of 13.2 mas and the position angle residuals exhibit rms deviation of 29. Factors affecting the measurement precision are discussed.

We have compiled a catalog of absolute proper motions of globular clusters from various sources. The sample consists of 38 clusters, from which most of the southern ones (15 clusters) were measured in our previous papers in this series. We have integrated orbits assuming two different Galactic potential models adopted from the literature and have calculated orbital parameters. The uncertainties associated with the orbital parameters were derived in a Monte Carlo approach, and we conclude that, overall, at the present level of measurement errors, orbital differences due to Galactic potential models are not significant. Three metal-poor clusters are found to have orbits similar to prototypical metal-rich disk clusters. These clusters are NGC 6254 (M10), NGC 6626 (M28), and NGC 6752. We interpret this as a potentially significant constraint on the formation of the disk. It is thus possible that part of the inner metal-poor halo is the low-metallicity tail of the thick disk. In this case, the ages of these clusters indicate that the formation of the disk partially overlapped with that of the halo. The clusters classified as young halo or red horizontal-branch by Zinn show a radially anisotropic velocity distribution, their orbits are of high total energy, with apocentric radii larger than 10 kpc and highly eccentric. In this sense they may represent an accreted component of our Galaxy. We also discuss ω Cen's orbit characteristics in the view of an accreted origin. We investigate the effect of the orbital motion on the internal dynamics of clusters. Adopting the formalism from Gnedin & Ostriker and their destruction rates due to two-body relaxation, we find that, in most cases, this internal process is more important than the destruction processes due to disk and bulge shocking. Hubble Space Telescope (HST) observations argue that NGC 6397's luminosity function is depleted at the faint end, and this is blamed on its high total destruction rate. We propose a list of clusters with similar destruction rates that may also have depleted luminosity functions. We also note the bias toward deriving higher destruction rates in studies that statistically assign tangential velocities based on a kinematic model of the globular cluster system, in contrast to the rates derived from the measured tangential velocities. Clusters prone to such biases are those that have circular orbits (kinematically thick-disk clusters) and some of those with orbits of high total energy.

Absolute proper motions have been measured for 10 clusters, in addition to the sample of five clusters presented in an earlier paper. These newly measured clusters are NGC 1904 (M79), NGC 2298, NGC 4590 (M68), NGC 5139 (ω Cen), NGC 5897, NGC 6093 (M80), NGC 6121 (M4), NGC 6144, NGC 6809 (M55), and NGC 7099 (M30). The correction to absolute proper motion is determined based on galaxies, except for one field with high extinction, for which we used the Hipparcos system. This latter correction proves to be very useful for fields at low Galactic latitude, provided magnitude-dependent systematics are well controlled. The errors in absolute proper motion per cluster range between 0.4 and 1.0 mas yr-1. Space velocities are also determined, and the kinematics are briefly discussed; a companion paper will present a detailed analysis of orbits in conjunction with other physical parameters of clusters.

Two hundred seventy-seven position angle and separation measures of 154 double stars are presented. Three of the systems were previously unknown to be double, and 16 other systems were discovered earlier this decade by the Hipparcos satellite. Measures are derived from speckle observations taken with the Wisconsin-Indiana-Yale-NOAO (WIYN) 3.5 m telescope located at Kitt Peak, Arizona. Speckle images were obtained using two different imaging detectors, namely, a multianode microchannel array (MAMA) detector and a fast-readout CCD. A measurement precision study was performed on a sample of binaries with extremely well known orbits by comparing the measures obtained here to the ephemeris predictions. For the CCD, the root mean square (rms) deviation of residuals was found to be 3.5 milliarcseconds (mas) in separation and 12 in position angle, while the residuals of the MAMA data varied depending on the magnification used and seeing conditions but can be comparable or superior to the CCD values. In addition, the two cameras were compared in terms of the detection limit in total magnitude and magnitude difference of the systems under study. The MAMA system has the ability to detect some systems with magnitude differences larger than 3.5, although reliable astrometry could not be obtained on these objects. Reliable astrometry was obtained on a system of magnitude difference of 5.3 with the CCD system.

We describe the Yale/San Juan Southern Proper Motion (SPM) Catalog 1.0, which provides positions, absolute proper motions, and photographic BV photometry for 58,880 objects at the South Galactic pole. The sky coverage of the SPM Catalog 1.0 is about 720 deg2 in the magnitude range 5 < V < 18.5. About 55% of all catalog stars are randomly chosen, whereas the remainder contains numerous astrophysically interesting objects drawn from various lists and databases. The accuracy of positions and absolute proper motions is 40–150 mas and 3–8 mas yr-1, respectively, depending on the star's magnitude. The high-end astrometric accuracy applies to the stars brighter than V = 15. A great deal of effort was put into correcting positions and proper motions for the magnitude-dependent systematic errors. The catalog can be used for Galactic structure studies and deep CCD-frame astrometric calibration and as a database for stars, galaxies, and other objects at the south Galactic pole. The catalog is supplemented by calibrated CCD BV photometry in selected 13' × 13' areas.

The M dwarf binary, Wolf 1062 (Gliese 748), has been observed with the Hubble Space Telescope (HST) Fine Guidance Sensor 3 in the transfer function scan mode to determine the apparent orbit. This is the first orbit defined fully and exclusively with HST, and is the most accurate definitive orbit for any resolved, noneclipsing system. The orbital period is 2.4490 ± 0.0119 yr and the semimajor axis is 01470 ± 00007—both quantities are now known to better than 1%. Using the weighted mean of seven parallax measurements and these HST data, we find the system mass to be 0.543 ± 0.031 M⊙, where the error of 6% is due almost entirely to the parallax error. An estimated fractional mass from the infrared brightness ratio and infrared mass-luminosity relation yields a mass for the primary of 0.37 M⊙, and the secondary falls in the regime of very low mass stars, with a mass of only 0.17 M⊙.

As with virtually all photographic plate material, the astrograph plates from which the Southern Proper Motion (SPM) catalog is being compiled suffer from magnitude-dependent systematic shifts in the image positions, i.e., a magnitude equation. If left uncorrected, these would adversely affect both the primary goals of the SPM catalog, the absolute proper motions, and the faint secondary reference frame. Using the diffraction-grating images present on the plates, a procedure is adopted that allows a spatially variant magnitude equation correction to be derived individually for each SPM plate. Application of the method to ~120 SPM fields, primarily around the south Galactic pole and the -30° and -35° declination zones, demonstrates its effectiveness. Indeed, the method proves superior, in the case of the SPM, to a direct calibration of the magnitude equation using the newly available Tycho Catalogue. The result of the diffraction-grating technique is final SPM positions and proper motions that are largely magnitude equation–free, as verified by numerous internal and external checks.

Five hundred thirty-one speckle measures of binary stars are reported. These data were taken mainly during the period 2008 June through 2009 October at the WIYN 3.5 m Telescope at Kitt Peak and represent the last data set of single-filter speckle observations taken in the WIYN speckle program prior to the use of the current two-channel speckle camera. The astrometric and photometric precision of these observations is consistent with previous papers in this series: we obtain a typical linear measurement uncertainty of approximately 2.5 mas, and the magnitude differences reported have typical uncertainties in the range of 0.1-0.14 mag. In combination with measures already in the literature, the data presented here permit the revision of the orbit of A 1634AB (= HIP 76041) and the first determination of visual orbital elements for HDS 1895 (= HIP 65982).

In this paper, we study the ability of CCD- and electron-multiplying-CCD-based speckle imaging to obtain reliable astrometry and photometry of binary stars below the diffraction limit of the WIYN 3.5 m Telescope. We present a total of 120 measures of binary stars, 75 of which are below the diffraction limit. The measures are divided into two groups that have different measurement accuracy and precision. The first group is composed of standard speckle observations, that is, a sequence of speckle images taken in a single filter, while the second group consists of paired observations where the two observations are taken on the same observing run and in different filters. The more recent paired observations were taken simultaneously with the Differential Speckle Survey Instrument, which is a two-channel speckle imaging system. In comparing our results to the ephemeris positions of binaries with known orbits, we find that paired observations provide the opportunity to identify cases of systematic error in separation below the diffraction limit and after removing these from consideration, we obtain a linear measurement uncertainty of 3-4 mas. However, if observations are unpaired or if two observations taken in the same filter are paired, it becomes harder to identify cases of systematic error, presumably because the largest source of this error is residual atmospheric dispersion, which is color dependent. When observations are unpaired, we find that it is unwise to report separations below approximately 20 mas, as these are most susceptible to this effect. Using the final results obtained, we are able to update two older orbits in the literature and present preliminary orbits for three systems that were discovered by Hipparcos.

We present absolute parallaxes and proper motions for seven members of the Hyades open cluster, pre-selected to lie in the core of the cluster. Our data come from archival astrometric data from FGS 3, and newer data for 3 Hyads from FGS 1R, both white-light interferometers on the Hubble Space Telescope (HST). We obtain member parallaxes from six individual Fine Guidance Sensor (FGS) fields and use the field containing van Altena 622 and van Altena 627 (= HIP 21138) as an example. Proper motions, spectral classifications and VJHK photometry of the stars comprising the astrometric refer- ence frames provide spectrophotometric estimates of reference star absolute parallaxes. Introducing these into our model as observations with error, we determine absolute parallaxes for each Hyad. The parallax of vA 627 is significantly improved by including a perturbation orbit for this previously known spectroscopic binary, now an astrometric binary. Compared to our original (1997) determina- tions, a combination of new data, updated calibration, and improved analysis lowered the individual parallax errors by an average factor of 4.5. Comparing parallaxes of the four stars contained in the Hipparcos catalog, we obtain an average factor of 11 times improvement with the HST . With these new results, we also have better agreement with Hipparcos for the four stars in common. These new parallaxes provide an average distance for these seven members, < D > = 47.5 pc, for the core a \pm 1 - �� dispersion depth of 3.6 pc, and a minimum depth from individual components of 16.0 \pm 0.9 pc. Absolute magnitudes for each member are compared to established main sequences, with excellent agreement. We obtain a weighted average distance modulus for the core of the Hyades of m-M=3.376 \pm 0.01, a value close to the previous Hipparcos values, m-M=3.33\pm 0.02., 21 pages, 7 figures, Astronomical Journal, accepted 2011-3-7

Relative proper motions for 663 stars in the field of the old open cluster M67 have been determined using 44 Yerkes 40-in refractor plates. The resulting proper-motion marginal distributions have been fit with a two-component model representing the sum of a cluster distribution and a much wider field distribution, both of which are assumed to be intrinsically Gaussian in form. The observed marginal distributions are actually quite non-Gaussian due to the effects of the proper-motion measurement errors, and thus a modeling procedure that realistically includes the measurement errors has been devised. The procedure yields excellent fits to the observed distributions, and thus allows reliable cluster-membership probabilities to be calculated. The cluster's intrinsic velocity dispersion is estimated from the proper motions of the about 80 brightest cluster stars to be 0.81 + or - 0.10 km/s. This is marginally higher than a dispersion estimate based on published radial-velocity measurements of a similar sample of cluster members. 16 refs.