718 research outputs found

    On the stellar content of the open clusters Melotte 105, Hogg 15, pismis 21 and Ruprecht 140

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    CCD observations in the B, V and I passbands have been used to generate colour-magnitude diagrams reaching down to V = 19 mag for two slightly characterized (Melotte 105 and Hogg 15) and two almost unstudied (Pismis 21 and Ruprecht 140) open clusters. The sample consists of about 1330 stars observed in fields of about 4'x4'. Our analysis shows that neither Pismis 21 nor Ruprecth 140 are genuine open clusters since no clear main sequences or other meaningful features can be seen in their colour-magnitude diagrams. Melotte 105 and Hogg 15 are open clusters affected by E(B-V) = 0.42 +/- 0.03 and 0.95 +/- 0.05, respectively. Their distances to the Sun have been estimated as 2.2 +/- 0.3 kpc and 2.6 +/- 0.8 kpc, respectively, while the corresponding ages estimated from empirical isochrones fitted to the main sequence cluster sequences are approximately 350 Myr and 300 Myr, respectively. The present data are not consistent with the membership of the WN6 star HDE 311884 to Hogg 15.Fil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    The apparent overdensity of open clusters in the Canis Major overdensity

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    The exciting debate on the existence and nature of the relatively recent discovery of the so-called Canis Major (CMa) overdensity is re-examined here based on the positions, reddenings, ages and metallicities of Galactic open clusters (OCs). The data used to carry out the current study were taken from the recently updated version of the Dias et al.'s 1776 OC catalogue. We found that only Tombaugh 2 is physically located within the main body of CMa. Even if we take into account the whole sample of catalogued OCs with unknown distances, it is statistically expected that only one additional OC could be found within the CMa region. Since the CMa overdensity appears to be quite transparent to dust, only a few OCs in that zone could have been missed. Both metallicity and age distributions of OCs located in the Galactic outer disc, including Tombaugh 2 and those projected on to CMa, are in good agreement with the paradigm of a main dispersion of age and metallicity values. There are only marginal indications for a radial abundance variation. We conclude that CMa does not contain a significant population of OCs which share its properties. This result does not favour the dwarf galaxy scenario. © 2008 The Authors. Journal compilation © 2008 RAS.Fil: Piatti, Andres Eduardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Claria Olmedo, Juan Jose. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentin

    NGC2587: a sparse open cluster projected on to a populous star field

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    We present CCD photometry in the Johnson U, B and V and Kron–Cousins I passbands for the open cluster NGC 2587. The sample consists of 4406 stars reaching down to V∼ 21.0. We developed a new method to clean statistically the colour–magnitude diagrams. NGC 2587 appears to be a sparse, relatively bright open cluster, with a few tens of members projected on to a populous star field. The comparatively bright F7/8 II type star HD 70927, located close to the cluster centre, seems not to be a member. Our analysis suggests that NGC 2587 is slightly younger than the Hyades and probably of solar metallicity. A cluster radius of roughly 8 arcmin was estimated from the radial stellar density profile. From 18 probable cluster members with measured proper motions, we derive the following mean values for NGC 2587: μα=−4.3 ± 3.6 mas yr−1 and μδ=−2.5 ± 3.4 mas yr−1. Adopting the theoretical metal content Z= 0.02, which provides the best global fit, we derive a cluster age of 500+60−50. Simultaneously, colour excesses E(B−V) = 0.10 and E(V−I) = 0.15 and an apparent distance modulus of V−MV= 12.50 are obtained. The interstellar extinction in the cluster direction is found to follow the normal law. NGC 2587 is located at a distance of (2.70 ± 0.70) kpc from the Sun and ∼9.8 kpc from the Galactic centre.Fil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Ahumada, Andrea Veronica. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. European Southern Observatory; Chil

    THE ANALYSIS OF FORMS AND MEANINGS OF PREFIXES FOUND IN BALI ADVERTISER

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    The title of this research is The Analysis Forms and Meanings of Prefixes Found in Bali Advertiser. The scopes of discussions in this research are the forms of prefixes found in Bali Advertiser and their meanings. The method in doing this research is qualitative research. The data source which is used in writing this research is Bali Advertiser, a newspaper which is used for advertisement for foreign community, and it is also used as the official English language media for the Direktorat Jenderal Pajak (Bali Tax Office). The main theory which is used in this research is the theory of Quirk in the book entitled A University Grammar of English. The books which are used as supporting theory are Morphology by Katamba and English Word - Formation by Bauer. After collecting and analyzing the data, there are many forms and meanings of prefixes found, they are: negative prefixes such as non-,and in-, reversative or privative prefixes such as un- and dis-, pejorative prefixes that is mis-, prefixes of degree or size such as super-, out-, sur-, over-, ultra- and mini-, prefixes of attitude such as co- and anti-, locative prefixes that is inter-, prefixes of time and order such as pre-, ex-, and re-, number prefixes such as bi- and multi-, other prefixes such as auto- and semi-, and conversion prefixes such as be- and en-

    LEKSIKOGRAMATIKA PADA IKLAN PARFUM POWER MUSK

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    Leksikogramatika dalam teori Linguistik Sistemik Fungsional selalu terikat dengan fungsi bahasa sebagai sebuah landasan dari terciptanya metafungsi bahasa. Tujuan penelitian ini adalah untuk melihat aplikasi dari leksikogramatika pada teks iklan parfum Power Musk dengan menggunakan kajian Linguistik Sistemik Fungsional. Data dalam penelitian ini berupa teks iklan parfum Power Musk yang dianalisis menggunakan metode deskriptif kualitatif. Pada level leksikogramatika ada tiga bagian penting yang merealisasikan metafungsi bahasa yaitu transitivitas, modus dan tema pada teks. Ketiga hal tersebut juga ditemukan pada penggunaan teks iklan parfum Power Musk yang merupakan hasil dari penelitian ini. Hasil penelitian menunjukkan dari segi transitivitas terdapat empat jenis proses yang digunakan dalam teks iklan parfum Power Musk dalam mempresentasikan pengalamannya yaitu proses mental, material, verbal dan relasional. Dalam segi keselarasan makna yang ingin disampaikan melalui teks ditemukan bahwa modus dan tema yang digunakan mampu mendeskripsikan pesan dari teks iklan parfum Power Musk

    Integrated spectral properties of 7 galactic open clusters

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    This paper presents flux-calibrated integrated spectra in the range 3600 - 9000 Å for 7 concentrated, relatively populous Galactic open clusters. We perform simultaneous estimates of age and foreground interstellar reddening by comparing the continuum distribution and line strengths of the cluster spectra with those of template cluster spectra with known parameters. For five clusters these two parameters have been determined for the first time (Ruprecht 144, BH 132, Pismis 21, Lyngå11 and BH 217), while the results here derived for the remaining two clusters (Hogg 15 and Melotte 105) show very good agreement with previous studies based mainly on colour-magnitude diagrams. We also provide metallicity estimates for six clusters from the equivalent widths of CaII triplet and TiO features. The present cluster sample improves the age resolution around solar metal content in the cluster spectral library for population synthesis. We compare the properties of the present sample with those of clusters in similar directions. Hogg 15 and Pismis 21 are among the most reddened clusters in sectors centered at l = 270° and l = 0°, respectively. Besides, the present results would favour an important dissolution rate of star clusters in these zones.Fil: Ahumada, Andrea Veronica. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Claria Olmedo, Juan Jose. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Bica, Eduardo. Universidade Federal do Rio Grande do Sul; BrasilFil: Piatti, Andres Eduardo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentin

    CREATING AN ENGLISH MATERIALS IN ORAL DISCOURSE ASPECT FOR THE TAXI DRIVERS

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    This research was concerned in creating an English material in oral discourse aspect for the Taxi Drivers. The research conducted based on the problems faced by the taxi drivers in the tourism object which need English as a main language in communicating with the international passenger. The improvement in English skill especially in oral discourse for the taxi drivers was aimed to provide a better service in their job which runs in tourism field. The method used in conducting the research consists of three steps; they are chose the data source, collect the data, and analyse the data. The data was taken by doing the interview and spread the questionnaire to the taxi drivers in Sanur. The material selection was done by selecting the most difficult aspect that the drivers thought in learning English especially in oral discourse aspect. The analysed data provide the basis in creating an English material for the drivers. The theory applied in this research are theory of Hutchinson and Waters in their book entitled English for Specific purpose (1987) as the main theory and the theory of Van Dijk (1993) in his book entitled Principles od Discourse analysis and Searle, J. R. (1696) in her book entitled Speech Acts, an essay in the philosophy of language as supporting theories. As the result, the English materials was created based on Hutchinson and Waters theory which consists of input, content focus, language focus and task. Those model of learning was the most suitable to the taxi driver seen from the layout and also the English material has more specific material organization by applied this model

    CCD Washington photometry of four poorly studied open clusters in the two inner quadrants of the galactic plane

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    Complementing our Washington photometric studies on Galactic open clusters (OCs), we now focus on four poorly studied OCs located in the first and fourth Galactic quadrants, namely BH 84, NGC 5381, BH 211 and Czernik 37. We have obtained CCD photometry in the Washington system CC and T1T_1 passbands down to T1T_1 \sim 18.5 magnitudes for these four clusters. Their positions and sizes were determined using the stellar density radial profiles. We derived reddening, distance, age and metallicity of the clusters from extracted (CT1,T1)(C-T_1,T_1) color-magnitude diagrams (CMDs), using theoretical isochrones computed for the Washington system. There are no previous photometric data in the optical band for BH 84, NGC 5381 and BH 211. The CMDs of the observed clusters show relatively well defined main sequences, except for Czernik 37, wherein significant differential reddening seems to be present. The red giant clump is clearly seen only in BH 211. For this cluster, we estimated the age in (1000200+260^{+260}_{-200}) Myr, assuming a metallicity of ZZ = 0.019. BH 84 was found to be much older than it was previously believed, while NGC 5381 happened to be much younger than previously reported. The heliocentric distances to these clusters are found to range between 1.4 and 3.4 kpc. BH 84 appears to be located at the solar galactocentric distance, while NGC 5381, BH 211 and Czernik 37 are situated inside the solar ring.Comment: 30 pages, 9 figures, 10 table

    Ca II triplet spectroscopy of small magellanic cloud red giants. II. abundances for a sample of field stars

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    We have obtained metallicities of ∼360 red giant stars distributed in 15 Small Magellanic Cloud (SMC) fields from near-infrared spectra covering the Ca II triplet lines using the VLT + FORS2. The errors of the derived [Fe/H] values range from 0.09 to 0.35 dex per star, with a mean of 0.17 dex. The metallicity distribution (MD) of the whole sample shows a mean value of [Fe/H] = -1.00 ± 0.02, with a dispersion of 0.32 0.01, in agreement with global mean [Fe/H] values found in previous studies. We find no evidence of a metallicity gradient in the SMC. In fact, on analyzing the MD of each field, we derived mean values of [Fe/H] = -0.99 ± 0.08 and [Fe/H] = -1.02 ± 0.07 for fields located closer and farther than 4° from the center of the galaxy, respectively. In addition, there is a clear tendency for the field stars to be more metal-poor than the corresponding cluster they surround, independent of their positions in the galaxy and of the clusters' age. We argue that this most likely stems from the field stars being somewhat older and therefore somewhat more metal-poor than most of our clusters. © 2010. The American Astronomical Society.Fil: Parisi, Maria Celeste. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Geisler, Doug. Universidad de Concepción; ChileFil: Grocholski, A. J.. University of Florida; Estados Unidos. Space Telescope Science Institute; Estados UnidosFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Sarajedini, A.. University of Florida; Estados Unido
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