Proper-motion binaries in the Hipparcos catalogue: comparison with radial velocity data

Context. This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue. Aims. The comparison of the proper motions constructed from positions spanning a short (Hipparcos) or long time (Tycho-2) makes it possible to uncover binaries with periods of the order of or somewhat larger than the short time span (in this case, the 3 yr duration of the Hipparcos mission), since the unrecognised orbital motion will then add to the proper motion. Methods. A list of candidate proper motion binaries is constructed from a carefully designed χ2 test evaluating the statistical significance of the difference between the Tycho-2 and Hipparcos proper motions for 103 134 stars in common between the two catalogues (excluding components of visual systems). Since similar lists of proper-motion binaries have already been constructed, the present paper focuses on the evaluation of the detection efficiency of proper-motion binaries, using different kinds of control data (mostly radial velocities). The detection rate for entries from the Ninth Catalogue of Spectroscopic Binary Orbits (SB9) is evaluated, as well as for stars like barium stars, which are known to be all binaries, and finally for spectroscopic binaries identified from radial velocity data in the Geneva-Copenhagen survey of F and G dwarfs in the solar neighbourhood. Results. Proper motion binaries are efficiently detected for systems with parallaxes in excess of ∼20 mas, and periods in the range 1000-30 000 d. The shortest periods in this range (1000-2000 d, i.e. once to twice the duration of the Hipparcos mission) may appear only as DMSA/G binaries (accelerated proper motion in the Hipparcos Double and Multiple System Annex). Proper motion binaries detected among SB9 systems having periods shorter than about 400 d hint at triple systems, the proper-motion binary involving a component with a longer orbital period. A list of 19 candidate triple systems is provided. Binaries suspected of having low-mass (brown-dwarf-like) companions are listed as well. Among the 37 barium stars with parallaxes larger than 5 mas, only 7 exhibit no evidence for duplicity whatsoever (be it spectroscopic or astrometric). Finally, the fraction of proper-motion binaries shows no significant variation among the various (regular) spectral classes, when due account is taken for the detection biases. © ESO 2007.

Chemically tagging the Hyades stream: does it partly originate from the Hyades cluster?

The Hyades stream has long been thought to be a dispersed vestige of the Hyades cluster. However, recent analyses of the parallax distribution, of the mass function, and of the action-space distribution of stream stars have shown it to be rather composed of orbits trapped at a resonance of a density disturbance. This resonant scenario should leave a clearly different signature in the element abundances of stream stars than the dispersed cluster scenario, since the Hyades cluster is chemically homogeneous. Here, we study the metallicity as well as the element abundances of Li, Na, Mg, Fe, Zr, Ba, La, Ce, Nd and Eu for a random sample of stars belonging to the Hyades stream, and compare them with those of stars from the Hyades cluster. From this analysis: (i) we independently confirm that the Hyades stream cannot be solely composed of stars originating in the Hyades cluster; (ii) we show that some stars (namely 2/21) from the Hyades stream nevertheless have abundances compatible with an origin in the cluster; (iii) we emphasize that the use of Li as a chemical tag of the cluster origin of main-sequence stars is very efficient in the range 5500 K <= T(eff) <= 6200 K, since the Li sequence in the Hyades cluster is very tight, while at the same time spanning a large abundance range; (iv) we show that, while this evaporated population has a metallicity excess of similar to 0.2 dex with respect to the local thin-disc population, identical to that of the Hyades cluster, the remainder of the Hyades stream population has still a metallicity excess of similar to 0.06-0.15 dex, consistent with an origin in the inner Galaxy and (v) we show that the Hyades stream can be interpreted as an inner 4:1 resonance of the spiral pattern: this then also reproduces an orbital family compatible with the Sirius stream, and places the origin of the Hyades stream up to 1 kpc inwards from the solar radius, which might explain the observed metallicity excess of the stream population.

THE INFRARED COLORS OF THE SUN

Solar infrared colors provide powerful constraints on the stellar effective temperature scale, but they must be measured with both accuracy and precision in order to do so. We fulfill this requirement by using line-depth ratios to derive in a model-independent way the infrared colors of the Sun, and we use the latter to test the zero point of the Casagrande et al. effective temperature scale, confirming its accuracy. Solar colors in the widely used Two Micron All Sky Survey (2MASS) JHK(s) and WISE W1-4 systems are provided: (V - J)(circle dot) = 1.198, (V - H)(circle dot) = 1.484, (V - K-s)(circle dot) = 1.560, (J - H)(circle dot) = 0.286, (J - K-s)(circle dot) = 0.362, (H - K-s)(circle dot) = 0.076, (V - W1)(circle dot) = 1.608, (V - W2)(circle dot) = 1.563, (V - W3)(circle dot) = 1.552, and (V - W4)(circle dot) = 1.604. A cross-check of the effective temperatures derived implementing 2MASS or WISE magnitudes in the infrared flux method confirms that the absolute calibration of the two systems agrees within the errors, possibly suggesting a 1% offset between the two, thus validating extant near-and mid-infrared absolute calibrations. While 2MASS magnitudes are usually well suited to derive T-eff, we find that a number of bright, solar-like stars exhibit anomalous WISE colors. In most cases, this effect is spurious and can be attributed to lower-quality measurements, although for a couple of objects (3%+/- 2% of the total sample) it might be real, and may hint at the presence of warm/hot debris disks.

Efeitos do freio magnético sobre a distribuição da rotação estelar

The pioneering work proposed by Skumanich (1972) has shown that the projected mean rotational velocity < v sini > for solar type stars follows a rotation law decreases with the time given by t −1/2 , where t is the stellar age. This relationship is consistent with the theories of the angular momentum loss through the ionized stellar wind, which in turn is coupled to the star through its magnetic field. Several authors (e.g.: Silva et al. 2013 and de Freitas et al. 2014) have analyzed the possible matches between the rotational decay and the profile of the velocity distribution. These authors came to a simple heuristic relationship, but did not build a direct path between the exponent of the rotational decay (j) and the exponent of the distribution of the rotational velocity (q). The whole theoretical scenario has been proposed using an efficient and strong statistical mechanics well known as non-extensive statistical mechanics. The present dissertation proposes effectively to close this issue by elaborating a theoretical way to modify the q-Maxwellians’ distributions into q-Maxwellians with physics links extracted from the theory of magnetic braking. In order to test our distributions we have used the GenevaCapenhagen Survey data with approximately 6000 F and G field stars limited by age. As a result, we obtained that the exponents of the decay law and distribution follow a similar relationship to that proposed by Silva et al. (2013).

ZIM-1: (blueprint) Plat of Survey ... Town of Geneva, Kane County, IL, March 1921

original file name DSC_0004

ZIM-3: (blueprint) A Plat of Topo Survey for The Property of Mr. H.B. Zimmerman, Geneva, IL, October 1921

original file name DSC_0004

ZIM-2: A Plat of Topo Survey for The Property of Mr. H.B. Zimmerman, Geneva, IL, October 1921

original file name DSC_0004

Second Welland Canal - Book 1, Survey Map 11 - St. Catharines and Locks 3 and 4

Survey map of the Second Welland Canal created by the Welland Canal Company showing the Town of St. Catharines. Identified structures associated with the Canal include Lock 3 and its Lock House, Lock 4 and its Lock House, Hydraulic Race, and a floating tow path. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include streets and roads (ex. Geneva Street, Ontario Street, St. Paul Street, and Merritville Road), Lincoln Mills and its Store House, T. M. Merritt's Store House, Cooper Shop, L. Shickluna's Dry Dock, Peter McGill's Grist Mill, J. Flint's Saw Factory, T. Hosteter's Gristing Mill, J. Dougan Builder's shop or office, Norris and Nelson Mill, G. N. Oil Foundry and its Machine Shop and Boiler, a barrel shed, woolen factory, Estate of P. Nihen (or T. Nihan), Norris and Nelson's Wharf, the W. C. Office, and structures (possibly houses) or small properties belonging to T. Adams, and A. K. Boomer. Properties and property owners of note are: Concession 6 Lots 16, 17, and 18, Concession 7 Lots 16, 17, and 18, Alva Dittrick, James R. Benson, W. B. Robinson, and C. Phelps.

Second Welland Canal - Book 1, Survey Map 12 - St. Catharines and Lock 4

Survey map of the Second Welland Canal created by the Welland Canal Company showing the Town of St. Catharines. Identified structures associated with the Canal include Lock 4, Hydraulic Race, floating tow path, and the Canal waterway itself. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include streets and roads (ex. Geneva Street, St. Paul Street, Queenston Street, Niagara Street and Mill Street), C. Phelp's Grist Mill and Store House, Stinson's Distillery, and several unnamed bridges. Properties and property owners of note are: Concession 6 Lot 16, J. R. Benson, Calvin Phelps, J. Hudson, David Gray, A. Roberts, Mrs. McDonell, J. S. McDonell, T. B. Wragg, J. Donaldson, W. Barr Jr., C. L. Hall, G. Ward, Ridout Bros and Co., and the St. Catharines Grass Co.

Second Welland Canal - Book 1, Survey Map 13 - St. Catharines and Locks 4 and 5

Survey map of the Second Welland Canal created by the Welland Canal Company showing the Town of St. Catharines. Identified structures associated with the Canal include Lock 4, Lock House, Lock 5, Small Lock House, the towing path, and Gasometer for Canal. The surveyors' measurements and notes can be seen in red and black ink and pencil. Local area landmarks are also identified and include streets and roads (ex. Geneva Street, Queenston Street, and Academy Street), C. Phelps Mill and Store House, St. Catharines and Welland Canal Gas Works, William Mahony's Tannery, Cooper Shop, a barrel shed, barn, and gas tanks. Properties and property owners of note are: Concession 6 Lots 14, 14, and 16, Concession 7 Lots 14, 15, and 16, C. Phelps, R. M. Clement, Orson Phelps, R. Collier, D. P. Haynes, W. Chace, and John Soper.

Abordajes teóricos en la comprensión de la influencia de los recursos económicos en la actividad física

Estudio cualitativo que analiza los abordajes teóricos utilizados por diferentes autores en la comprensión de la influencia de los recursos económicos en la actividad física desde los modelos de determinantes y determinación social.

Usage of complementary medicine across Switzerland. Results of the Swiss Health Survey 2007

QUESTIONS UNDER STUDY: This study investigated the use among the Swiss adult population and regional dissemination of various methods of complementary medicine (CM) provided by physicians or therapists in Switzerland. METHODS: Data of the Swiss Health Survey 2007 were used, which comprised a telephone interview followed by a written questionnaire (18,760 and 14,432 respondents, respectively) and included questions about people's state of health, health insurance and usage of health services. Users and non-users of CM were compared using logistic regression models. RESULTS: The most popular CM methods were homeopathy, osteopathy, acupuncture and shiatsu/foot reflexology. 30.5% of women and 15.2% of men used at least one CM method in the 12 months preceding the survey. Lake Geneva region and central Switzerland had more CM users than the other regions. Women, people between 25 and 64 years of age and people with higher levels of education were more likely to use CM. 53.5% of the adult population had a supplemental health insurance for CM treatments. 32.9% of people with such an insurance used CM during the 12 months preceding the survey, and so did 12.0% of people without additional insurance. CONCLUSIONS: Almost one fourth of the Swiss adult population had used CM within the past 12 months. User profiles were comparable to those in other countries. Despite a generally lower self-perceived health status, elderly people were less likely to use CM.

Low prevalence of atrial fibrillation in asymptomatic adults in Geneva, Switzerland

Aims To determine the prevalence of atrial fibrillation (AF) in a population-based sample of adults. Methods and results Between January 2005 and December 2007 individuals aged >/=50 years, residents of the city of Geneva, who had participated in a previous random survey were invited for follow-up examination. AF was assessed on a single resting 6-lead ECG. Reported prevalences were standardized for the age distribution of Canton Geneva. Overall participation was 72.8%. Twenty-nine cases of AF (22 men) were diagnosed among 3285 subjects (1696 men). The crude prevalence of AF (95% CI) was 0.88% (0.86, 0.90) overall, but higher in men [1.30% (1.26, 1.34)] than in women [0.44% (0.41, 0.47)]. The age-standardized AF prevalence was slightly higher [overall: 0.94% (0.91, 0.97), men: 1.23% (1.19, 1.27), women: 0.54% (0.47, 0.61)]. AF prevalence increased with age in both sexes. A 'history of suspected arterial embolism' (brain or legs) was higher in the AF cases (10.3 vs. 3.3%; P = 0.03). Conclusion This population-based survey of a general Swiss population indicates that the prevalence of AF remains below 1%. These results are less alarming than those from previous studies based on patients seeking medical care.