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A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)
Lépine, Sébastien; Shara, Michael M.
The LSPM catalog is a comprehensive list of 61,977 stars north of the J2000 celestial equator that have proper motions larger than 0.15" yr-1 (local-background-stars frame). The catalog has been generated primarily as a result of our systematic search for high proper motion stars in the Digitized Sky Surveys using our SUPERBLINK softwar…
Herbig Ae/Be Stars in nearby OB Associations
Berlind, Perry; Hartmann, Lee; Calvet, Nuria +3 more
We have carried out a study of the early-type stars in nearby OB associations spanning an age range of ~3-16 Myr, with the aim of determining the fraction of stars that belong to the Herbig Ae/Be class. We studied the B, A, and F stars in the nearby (<=500 pc) OB associations Upper Scorpius, Perseus OB2, Lacerta OB1, and Orion OB1, with members…
Statistical Constraints for Astrometric Binaries with Nonlinear Motion
Makarov, V. V.; Kaplan, G. H.
Useful constraints on the orbits and mass ratios of astrometric binaries in the Hipparcos catalog are derived from the measured proper motion differences of Hipparcos and Tycho-2 (Δµ), accelerations of proper motions (µ˙), and second derivatives of proper motions (µ̈). It is shown how, in some cases, statistical bounds can be esti…
Confirmation of Errors in Hipparcos Parallaxes from Hubble Space Telescope Fine Guidance Sensor Astrometry of the Pleiades
Soderblom, David R.; Benedict, G. Fritz; McArthur, Barbara +4 more
We present absolute trigonometric parallaxes and relative proper motions for three members of the Pleiades, obtained with the Hubble Space Telescope's Fine Guidance Sensor 1r, a white-light interferometer. We estimate spectral types and luminosity classes of the stars comprising the astrometric reference frame from R~2000 spectra, VJHK photometry,…
Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry
Fitzpatrick, E. L.; Massa, D.
We present a new calibration of optical (UBV, Strömgren uvbyβ, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars derived from Kurucz ATLAS9 model atmospheres. Our sample of stars consists of 45 normal nearby B and early A stars that have high-quality, low-resolution IUE spectra and accurate Hi…
Keck HIRES Spectroscopy of Four Candidate Solar Twins
King, Jeremy R.; Boesgaard, Ann M.; Schuler, Simon C.
We use high signal-to-noise ratio, high-resolution Keck HIRES spectroscopy of four solar twin candidates (HIP 71813, 76114, 77718, and 78399) pulled from our Hipparcos-based Ca II H and K survey to carry out parameter and abundance analyses of these objects. Our spectroscopic Teff estimates are ~100 K hotter than the photometric scale of the recen…
HD 166181 = V815 Herculis, a Single-lined Spectroscopic Multiple System
Pourbaix, D.; Fekel, Francis C.; Scarfe, C. D. +2 more
We have obtained extensive spectroscopic and velocity spectrometer observations of HD 166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343 days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the…
An Astrometric Study of the Binary Star α Ophiuchi
Gatewood, George
The work reported here combines data from the Multichannel Astrometric Photometer (MAP), the European astrometric satellite, Hipparcos, and infrared speckle observations of the nearby subgiant binary star system α Oph. The A5 IV primary is found to have a mass of 2.84+/-0.19 Msolar, while the approximately K2 V companion has a mass of 0…
Orbit, Dynamical Mass, and MK Type of Visual Binary WOR 2
Docobo, J. A.; Balega, Y. Y.; Tamazian, V. S. +2 more
On the basis of new speckle measurements with the 6 m telescope of the Special Astrophysical Observatory (Russia) and Hipparcos astrometry, an improved orbital solution with a period of P=24.1 yr for the visual binary WOR 2 is obtained. The dynamical mass of the system is 1.40+/-0.25 Msolar. Differential photometry (Δm=0.55 mag) allowed…