Browsing by Author "Villanueva, V."

Now showing 1 - 4 of 4
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    Discovery of a brown dwarf companion to the A3V star beta Circini
    (2015) Smith, L.; Lucas, P.; Pena, C.; Kurtev, R.; Marocco, F.; Jones, H.; Beamin Muhlenbrock, Juan Carlos; Napiwotzki, R.; Borissova, J.; Burningham, B.; Faherty, J.; Pinfield, D.; Gromadzki, M.; Ivanov, V.; Minniti, D.; Stimson, W.; Villanueva, V.
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    VALES V : a kinematic analysis of the molecular gas content in H-ATLAS galaxies at z similar to 0.03-0.35 using ALMA
    (2019) Molina, J.; Ibar, Edo; Villanueva, V.; Escala, A.; Cheng, C.; Baes, M.; Messias, H.; Yang, C.; Bauer, Franz Erik; Werf, van der
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    VVV high proper motion stars - I. The catalogue of bright K-S <= 13.5 stars
    (OXFORD UNIV PRESS, 2017) Kurtev, R.; Gromadzki, M.; Beamin, J. C.; Folkes, S. L.; Ramirez, K. Pena; Ivanov, V. D.; Borissova, J.; Villanueva, V.; Minniti, D.; Mendez, R.; Lucas, P. W.; Smith, L. C.; Pinfield, D. J.; Kuhn, M. A.; Jones, H. R. A.; Antonova, A.; Yip, A. K. P.
    Knowledge of the stellar content near the Sun is important for a broad range of topics ranging from the search for planets to the study of Milky Way (MW) structure. The most powerful method for identifying potentially nearby stars is proper motion (PM) surveys. All old optical surveys avoid, or are at least substantially incomplete, near the Galactic plane. The depth and breadth of the 'VISTA Variables in Via Lactea' (VVV) near-IR survey significantly improves this situation. Taking advantage of the VVV survey data base, we have measured PMs in the densest regions of the MW bulge and southern plane in order to complete the census of nearby objects. We have developed a custom PM pipeline based on VVV catalogues from the Cambridge Astronomy Survey Unit, by comparing the first epoch of JHKS with the multiepoch K-S bands acquired later. Taking advantage of the large time baseline between the Two Micron All Sky Survey (2MASS) and the VVV observations, we also obtained 2MASS-VVV PMs. We present a near-IR PMcatalogue for the whole area of the VVV survey, which includes 3003 moving stellar sources. All of these have been visually inspected and are real PM objects. Our catalogue is in very good agreement with the PM data supplied in IR catalogues outside the densest zone of the MW. The majority of the PM objects in our catalogue are nearby M-dwarfs, as expected. This new data base allows us to identify 57 common PM binary candidates, among which are two new systems within 30 pc of the Sun.
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    VVV IR high proper motion stars
    (UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA, 2015) Kurtev, R.; Gromadzki, M.; Beamin Muhlenbrock, Juan Carlos; Pena, K.; Folkes, S.; Ivanov, V. D.; Borissova, J.; Kuhn, M.; Villanueva, V.; Minniti, D.; Mendez, R.; Lucas, P.; Smith, L.; Pinfield, D.; Antonova, A.; Vieira, K; VanAltena, W; Mendez, RA
    We used the VISTA Variables en Via Lactea (VVV) survey to search for large proper motion (PM) objects in the zone of avoidance in the Milky Way bulge and southern Galactic disk. This survey is multi-epoch and already spans a period of more than four years, giving us an excellent opportunity for proper motion and parallax studies. We found around 1700 PM objects with PM>30 mas yr(-1). The majority of them are early and mid M-dwarfs. There are also few later spectral type objects, as well as numerous new K- and G-dwarfs. 75 of the stars have PM>300 mas(-1) and 189 stars have PM>200 mas(-1). There are only 42 previously known stars in the VVV area with proper motion PM>200 mas(-1). We also found three dM+WD binaries and new members of the immediate solar vicinity of 25 pc. We generated a catalog which will be a complementary to the existing catalogs outside this zone.