Browsing by Author "Jordan, A."
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- ItemDiscovery of VVV CL001 A low-mass globular cluster next to UKS 1 in the direction of the Galactic bulge(EDP SCIENCES S A, 2011) Minniti, D.; Hempel, M.; Toledo, I.; Ivanov, V. D.; Alonso Garcia, J.; Saito, R. K.; Catelan, M.; Geisler, D.; Jordan, A.; Borissova, J.; Zoccali, M.; Kurtev, R.; Carraro, G.; Barbuy, B.; Claria, J.; Rejkuba, M.; Emerson, J.; Moni Bidin, C.Context. It is not known how many globular clusters may remain undetected towards the Galactic bulge.
- ItemHAT-P-27b: A HOT JUPITER TRANSITING A G STAR ON A 3 DAY ORBIT(2011) Beky, B.; Bakos, G. A.; Hartman, J.; Torres, G.; Latham, D. W.; Jordan, A.; Arriagada, P.; Bayliss, D.; Kiss, L. L.; Kovacs, Geza; Quinn, S. N.; Marcy, G. W.; Howard, A. W.; Fischer, D. A.; Johnson, J. A.; Esquerdo, G. A.; Noyes, R. W.; Buchhave, L. A.; Sasselov, D. D.; Stefanik, R. P.; Perumpilly, G.; Lazar, J.; Papp, I.; Sari, P.We report the discovery of HAT-P-27b, an exoplanet transiting the moderately bright G8 dwarf star GSC 0333-00351 (V = 12.214). The orbital period is 3.039586 +/- 0.000012 days, the reference epoch of transit is 2455186.01879 +/- 0.00054 (BJD), and the transit duration is 0.0705 +/- 0.0019 days. The host star with its effective temperature 5300 +/- 90 K is somewhat cooler than the Sun and is more metal-rich with a metallicity of +0.29 +/- 0.10. Its mass is 0.94 +/- 0.04 M-circle dot and radius is 0.90(-0.04)(+0.05) R-circle dot. For the planetary companion we determine a mass of 0.660 +/- 0.033 M-J and radius of 1.038(-0.058)(+0.077) R-J. For the 30 known transiting exoplanets between 0.3 M-J and 0.8 M-J, a negative correlation between host star metallicity and planetary radius and an additional dependence of planetary radius on equilibrium temperature are confirmed at a high level of statistical significance.
- ItemHATS-2b: A transiting extrasolar planet orbiting a K-type star showing starspot activity(2013) Mohler-Fischer, M.; Mancini, L.; Hartman, J. D.; Bakos, G. A.; Penev, K.; Bayliss, D.; Jordan, A.; Csubry, Z.; Zhou, G.; Rabus, M.; Nikolov, N.; Brahm, R.; Espinoza, N.; Buchhave, L. A.; Beky, B.; Suc, V.; Csak, B.; Henning, T.; Wright, D. J.; Tinney, C. G.; Addison, B. C.; Schmidt, B.; Noyes, R. W.; Papp, I.; Lazar, J.; Sari, P.; Conroy, P.We report the discovery of HATS-2b, the second transiting extrasolar planet detected by the HATSouth survey. HATS-2b is moving on a circular orbit around a V = 13.6 mag, K-type dwarf star (GSC 6665-00236), at a separation of 0.0230 +/- 0.0003 AU and with a period of 1.3541 days. The planetary parameters have been robustly determined using a simultaneous fit of the HATSouth, MPG/ESO 2.2m/GROND, Faulkes Telescope South/Spectral transit photometry, and MPG/ESO 2.2m/FEROS, Euler 1.2m/CORALIE, AAT 3.9m/CYCLOPS radial-velocity measurements. HATS-2b has a mass of 1.37 +/- 0.16 MJ, a radius of 1.14 +/- 0.03 RJ, and an equilibrium temperature of 1567 +/- 30 K. The host star has a mass of 0.88 +/- 0.04 M fi and a radius of 0.89 +/- 0.02 R fi, and it shows starspot activity. We characterized the stellar activity by analyzing two photometric follow-up transit light curves taken with the GROND instrument, both obtained simultaneously in four optical bands (covering the wavelength range of 3860 9520 angstrom). The two light curves contain anomalies compatible with starspots on the photosphere of the host star along the same transit chord.
- ItemMapping Milky Way And Local Volume Structure With LSST(2011) Geha, Marla C.; Willman, B.; Bochanski, J.; Bullock, J.; Catelan, Márcio; Debattista, V.; Grillmair, C.; Jordan, A.; Juric, M.; Kalirai, J.; Kallivayalil, N.; McGehee, P.; Minniti, D.; Munoz, R.; Roskar, R.; Sarajedini, A.; Simon, J.; Strader, J.The LSST will yield revolutionary, multi-dimensional maps of the Milky Way (MW) galaxy and its neighbors. With its planned 1000 epochs over 6 bands and a final limiting magnitude of r=27.5 (AB mag; 5-sigma), it will provide an excellent resource for mapping the structure and accretion history of the MW and beyond in a way that the present generation of surveys can only hint at. LSST is expected to catalog 10 billion stars, including photometric metallicities for the 200 million F/G stars within 100 kpc and map the tangential velocity field of stars bright than r=24 mag to at least 10 kpc (at 10 km/s precision) and as far as 25 kpc (at 60 km/s precision). Specific related science to be enabled by LSST includes: mapping the 3D distribution of dust in the MW's disk, including variations in RV; understanding the smooth distribution of stars in the MW and other nearby galaxies; understanding large-scale chemical gradients in the MW; discovering lumps and streams in metallicity and phase-space; inferring the mass distribution in the MW; discovering ultra-faint galaxies throughout the Local Volume....
- ItemThe nature of UCDs(2008) Mieske, S.; Hilker, M.; Jordan, A.; Infante, L.; Kissler-Patig, M.; Rejkuba, M.; Richtler, T.; Cote, P.; Baumgardt, H.; West, M. J.; Ferrarese, L.; Peng, E. W.Context. The internal dynamics of ultra-compact dwarf galaxies (UCDs) has attracted increasing attention, with most of the UCDs studied to date located in the Virgo cluster.
- ItemThe White Dwarf Binary Pathways Survey -III. Contamination from hierarchical triples containing a white dwarf(2020) Lagos, F.; Schreiber, M. R.; Parsons, S. G.; Zurlo, A.; Mesa, D.; Gansicke, B. T.; Brahm, R.; Caceres, C.; Canovas, H.; Hernandez, M-S; Jordan, A.; Koester, D.; Schmidtobreick, L.; Tappert, C.; Zorotovic, M.The White Dwarf Binary Pathways Survey aims at increasing the number of known detached A, F, G, and K main-sequence stars in close orbits with white dwarf companions (WD+AFGK binaries) to refine our understanding about compact binary evolution and the nature of Supernova Ia progenitors. These close WD+AFGK binary stars are expected to form through common envelope evolution, in which tidal forces tend to circularize the orbit. However, some of the identified WD+AFGK binary candidates show eccentric orbits, indicating that these systems are either formed through a different mechanism or perhaps they are not close WD+AFGK binaries. We observed one of these eccentric WD+AFGK binaries with SPHERE and find that the system TYC 7218-934-1 is in fact a triple system where the WD is a distant companion. The inner binary likely consists of the G-type star plus an unseen low-mass companion in an eccentric orbit. Based on this finding, we estimate the fraction of triple systems that could contaminate the WD+AFGK sample. We find that less than 15 per cent of our targets with orbital periods shorter than 100 d might be hierarchical triples.
- ItemTwo long-period transiting exoplanets on eccentric orbits: NGTS-20 b (TOI-5152 b) and TOI-5153 b(2022) Ulmer-Moll, S.; Lendl, M.; Gill, S.; Villanueva, S.; Hobson, M. J.; Bouchy, F.; Brahm, R.; Dragomir, D.; Grieves, N.; Mordasini, C.; Anderson, D. R.; Acton, J. S.; Bayliss, D.; Bieryla, A.; Burleigh, M. R.; Casewell, S. L.; Chaverot, G.; Eigmueller, P.; Feliz, D.; Gaudi, B. S.; Gillen, E.; Goad, M. R.; Gupta, A. F.; Gunther, M. N.; Henderson, B. A.; Henning, T.; Jenkins, J. S.; Jones, M.; Jordan, A.; Kendall, A.; Latham, D. W.; Mireles, I; Moyano, M.; Nadol, J.; Osborn, H. P.; Pepper, J.; Pinto, M. T.; Psaridi, A.; Queloz, D.; Quinn, S.; Rojas, F.; Sarkis, P.; Schlecker, M.; Tilbrook, R. H.; Torres, P.; Trifonov, T.; Udry, S.; Vines, J., I; West, R.; Wheatley, P.; Yao, X.; Zhao, Y.; Zhou, G.Context. Long-period transiting planets provide the opportunity to better understand the formation and evolution of planetary systems. Their atmospheric properties remain largely unaltered by tidal or radiative effects of the host star, and their orbital arrangement reflects a different and less extreme migrational history compared to close-in objects. The sample of long-period exoplanets with well-determined masses and radii is still limited, but a growing number of long-period objects reveal themselves in the Transiting Exoplanet Survey Satellite (TESS) data.
- ItemVISTA Variables in the Via Lactea (VVV): The public ESO near-IR variability survey of the Milky Way(ELSEVIER, 2010) Minniti, D.; Lucas, P. W.; Emerson, J. P.; Saito, R. K.; Hempel, M.; Pietrukowicz, P.; Ahumada, A. V.; Alonso, M. V.; Alonso Garcia, J.; Arias, J. I.; Bandyopadhyay, R. M.; Barba, R. H.; Barbuy, B.; Bedin, L. R.; Bica, E.; Borissova, J.; Bronfman, L.; Carraro, G.; Catelan, M.; Claria, J. J.; Cross, N.; de Grijs, R.; Dekany, I.; Drew, J. E.; Farina, C.; Feinstein, C.; Fernandez Lajus, E.; Gamen, R. C.; Geisler, D.; Gieren, W.; Goldman, B.; Gonzalez, O. A.; Gunthardt, G.; Gurovich, S.; Hambly, N. C.; Irwin, M. J.; Ivanov, V. D.; Jordan, A.; Kerins, E.; Kinemuchi, K.; Kurtev, R.; Lopez Corredoira, M.; Maccarone, T.; Masetti, N.; Merlo, D.; Messineo, M.; Mirabel, I. F.; Monaco, L.; Morelli, L.; Padilla, N.; Palma, T.; Parisi, M. C.; Pignata, G.; Rejkuba, M.; Roman Lopes, A.; Sale, S. E.; Schreiber, M. R.; Schroeder, A. C.; Smith, M.; Sodre, L., Jr.; Soto, M.; Tamura, M.; Tappert, C.; Thompson, M. A.; Toledo, I.; Zoccali, M.; Pietrzynski, G.We describe the public ESO near-IR variability survey (VVV) scanning the Milky Way bulge and an adjacent section of the mid-plane where star formation activity is high. The survey will take 1929 h of observations with the 4-m VISTA telescope during 5 years (2010-2014), covering similar to 10(9) point sources across an area of 520 deg(2), including 33 known globular clusters and similar to 350 open clusters. The final product will be a deep near-IR atlas in five passbands (0.9-2.5 mu m) and a catalogue of more than 106 variable point sources. Unlike single-epoch surveys that, in most cases, only produce 2-D maps, the VVV variable star survey will enable the construction of a 3-D map of the surveyed region using well-understood distance indicators such as RR Lyrae stars, and Cepheids. It will yield important information on the ages of the populations. The observations will be combined with data from MACHO, OGLE, EROS, VST, Spitzer, HST, Chandra, INTEGRAL, WISE, Fermi LAT, XMM-Newton, GAIA and ALMA for a complete understanding of the variable sources in the inner Milky Way. This public survey will provide data available to the whole community and therefore will enable further studies of the history of the Milky Way, its globular cluster evolution, and the population census of the Galactic Bulge and center, as well as the investigations of the star forming regions in the disk. The combined variable star catalogues will have important implications for theoretical investigations of pulsation properties of stars. (C) 2009 Elsevier B.V. All rights reserved.
- ItemVVV DR1: The first data release of the Milky Way bulge and southern plane from the near-infrared ESO public survey VISTA variables in the Via Lactea(EDP SCIENCES S A, 2012) Saito, R. K.; Hempel, M.; Minniti, D.; Lucas, P. W.; Rejkuba, M.; Toledo, I.; Gonzalez, O. A.; Alonso Garcia, J.; Irwin, M. J.; Gonzalez Solares, E.; Hodgkin, S. T.; Lewis, J. R.; Cross, N.; Ivanov, V. D.; Kerins, E.; Emerson, J. P.; Soto, M.; Amores, E. B.; Gurovich, S.; Dekany, I.; Angeloni, R.; Beamin, J. C.; Catelan, M.; Padilla, N.; Zoccali, M.; Pietrukowicz, P.; Bidin, C. Moni; Mauro, F.; Geisler, D.; Folkes, S. L.; Sale, S. E.; Borissova, J.; Kurtev, R.; Ahumada, A. V.; Alonso, M. V.; Adamson, A.; Arias, J. I.; Bandyopadhyay, R. M.; Barba, R. H.; Barbuy, B.; Baume, G. L.; Bedin, L. R.; Bellini, A.; Benjamin, R.; Bica, E.; Bonatto, C.; Bronfman, L.; Carraro, G.; Chene, A. N.; Claria, J. J.; Clarke, J. R. A.; Contreras, C.; Corvillon, A.; de Grijs, R.; Dias, B.; Drew, J. E.; Farina, C.; Feinstein, C.; Fernandez Lajus, E.; Gamen, R. C.; Gieren, W.; Goldman, B.; Gonzalez Fernandez, C.; Grand, R. J. J.; Gunthardt, G.; Hambly, N. C.; Hanson, M. M.; Helminiak, K. G.; Hoare, M. G.; Huckvale, L.; Jordan, A.; Kinemuchi, K.; Longmore, A.; Lopez Corredoira, M.; Maccarone, T.; Majaess, D.; Martin, E. L.; Masetti, N.; Mennickent, R. E.; Mirabel, I. F.; Monaco, L.; Morelli, L.; Motta, V.; Palma, T.; Parisi, M. C.; Parker, Q.; Penaloza, F.; Pietrzynski, G.; Pignata, G.; Popescu, B.; Read, M. A.; Rojas, A.; Roman Lopes, A.; Ruiz, M. T.; Saviane, I.; Schreiber, M. R.; Schroeder, A. C.; Sharma, S.; Smith, M. D.; Sodre, L., Jr.; Stead, J.; Stephens, A. W.; Tamura, M.; Tappert, C.; Thompson, M. A.; Valenti, E.; Vanzi, L.; Walton, N. A.; Weidmann, W.; Zijlstra, A.Context. The ESO public survey VISTA variables in the Via Lactea (VVV) started in 2010. VVV targets 562 sq. deg in the Galactic bulge and an adjacent plane region and is expected to run for about five years.