Browsing by Author "Hajdu, G."

Now showing 1 - 12 of 12
  • Thumbnail Image
    Item
    A machine learned classifier for RR Lyrae in the VVV survey
    (2016) Elorrieta López, Felipe; Eyheramendy Duerr, Susana; Jordán Colzani, Andrés Cristóbal; Dekany, Istvan; Catelan, Márcio; Angeloni, Rodolfo; Alonso, J.; Contreras, R.; Gran, F.; Hajdu, G.; Espinoza, N.; Saito, R.; Minniti, D.
  • Thumbnail Image
    Item
    An UXor among FUors: Extinction-related Brightness Variations of the Young Eruptive Star V582 Aur
    (2018) Abraham, P.; Kospal, A.; Kun, M.; Feher, O.; Zsidi, G.; Acosta-Pulido, J. A.; Carnerero, M. I.; Garcia-Alvarez, D.; Moor, A.; Cseh, B.; Hajdu, G.; Hanyecz, O.; Kelemen, J.; Kriskovics, L.; Marton, G.; Mezo, Gy.; Molnar, L.; Ordasi, A.; R
  • Thumbnail Image
    Item
    Blazhko modulation in the infrared
    (2018) Jurcsik, J.; Hajdu, G.; Dekany, Istvan; Nuspl, J.; Catelan, Márcio; Grebel, E. K.
  • Thumbnail Image
    Item
    Discovery of a pair of classical cepheids in an invisible cluster beyond the galactic bulge
    (2015) Dekany, Istvan; Minniti, D.; Hajdu, G.; Alonso-Garcia, J.; Hempel, Maren; Palma, T.; Catelan, Márcio; Gieren Waiblinger, Wolfgang Paul; Majaess, D.
  • Thumbnail Image
    Item
    Milky Way metallicity gradient from Gaia DR2 F/1O double-mode Cepheids
    (2018) Lemasle, B.; Hajdu, G.; Kovtyukh, V.; Inno, L.; Grebel, E. K.; Catelan, Márcio; Bono, G.; François, P.; Kniazev, A.; da Silva, R.; Storm, J.
  • No Thumbnail Available
    Item
    Near-Field Cosmology with RR Lyrae Variable Stars: a first view of substructure in the southern sky
    (2016) Navarrete, C.; Duffau, S.; Vivas, A. K.; Catelan, Márcio; Hajdu, G.; Torrealba, G.; Cortés, C.; Belokurov, V.; Koposov, S.; Drake, A. J.
    We present the current status of the spectroscopic follow-up of a large number of RR Lyrae (RRL) halo overdensity candidates recently found by Torrealba et al. (2015) using southern-hemisphere data from the Catalina Real-time Transient Survey (CRTS). Characterizing the individual RRL stars in these overdensities is crucial to confirm them as real halo substructures. Low-resolution spectra have been obtained for RRL stars in 11 different overdensities, using the SOAR and Magellan telescopes. Radial velocities and metallicities have been derived so far for 123 and 99 RRL stars, respectively....
  • Thumbnail Image
    Item
    New galactic multi-mode cepheids from the ASAS-SN survey
    (2018) Jurcsik, J.; Hajdu, G.; Catelan, Márcio
  • Thumbnail Image
    Item
    Period change rates of Large Magellanic Cloud Cepheids using mesa
    (2022) Espinoza-Arancibia, F.; Catelan, Márcio; Hajdu, G.; Rodríguez-Segovia, N.; Boggiano, G.; Joachimi, K.; Muñoz-López, C.; Órdenes-Huanca, C.; Orquera-Rojas, C.; Torres, P.; Valenzuela-Navarro, Á.
  • Thumbnail Image
    Item
    Period-change rates in Large Magellanic Cloud Cepheids revisited
    (2021) Rodríguez-Segovia, N.; Hajdu, G.; Catelan, Márcio; Espinoza-Arancibia, F.; Boggiano, G.; Cenzano, C.; Garcés, E. H.; Joachimi, K.; Muñoz-López, C.; Órdenes-Huanca, C.; Orquera-Rojas, C.; Torres, P.; Valenzuela-Navarro, Á.
  • No Thumbnail Available
    Item
    Search for Evolutionary Changes in the Periods of Cepheids: V1033 Cyg, a Classical Cepheid at the First Crossing of the Instability Strip
    (2019) Berdnikov, L. N.; Pastukhova, E. N.; Kovtyukh, V. V.; Lemasle, B.; Kniazev, A. Yu; Usenko, I. A.; Bono, G.; Grebel, E.; Hajdu, G.; Zhuiko, S. V.; Udovichenko, S. N.; Keir, L. E.
    For the classical Cepheid V1033 Cyg we have constructed an OC diagram spanning a time interval of 117 years. The OC diagram has the shape of a parabola, which has made it possible to determine for the first time the quadratic light elements and to calculate the rate of evolutionary increase in the period dP/dt = 18.19 (+/- 0.08) syr(-1), in agreement with the results of theoretical calculations for the first crossing of the instability strip. Thus, V1033 Cyg is the second actually observed Cepheid (after UMi) that crosses the instability strip for the first time.
  • No Thumbnail Available
    Item
    The VVV Templates Project
    (2014) Contreras Ramos, R.; Catelan, Marcio; Gran, F.; Navarrete, C.; Angeloni, R.; Alonso-García, J.; Dékány, I.; Hajdu, G.; Hempel, M.; Jordán, A.; Townsend, B.; Borissova, J.; Navarro, C.; Pichara, K.; Eyheramendy, S.
    Until now, stellar variability in the near-IR has been a relatively ill-explored research field. In particular, the number of high-quality light curves is very limited and, even worse, many variability classes have not yet been observed in a sufficiently extensive way in the near-IR, so that good light curves are entirely lacking for some such classes. Since VVV is the first ever large survey dedicated to stellar variability in the near-infrared, the first problem we had to face has thus been the construction of a proper statistically significant database of high-quality (i.e., template) near-IR light curves for a significant sample of stars taken to be representative of the different variability classes under study. The main purpose of the VVV Templates Project is thus to build a large database of well-defined, high-quality, near-IR light curves for variable stars of different types, which will form the basis of the VVV automated classification algorithms...
  • Thumbnail Image
    Item
    The VVV Templates Project Towards an automated classification of VVV light-curves I. Building a database of stellar variability in the near-infrared
    (2014) Angeloni, Rodolfo; Contreras, R.; Catelan, Márcio; Dekany, Istvan; Gran Merino, Felipe Eduardo; Alonso García, J.; Hempel, Maren; Navarrete Silva, Camila Andrea; Andrews, H.; Beamin, J.; Berger Silva, Christian; Espinoza, N.; Eyheramendy Duerr, Susana; Hajdu, G.; Hempel, A.; Ita, Y.; Jordán Colzani, Andrés Cristóbal; Minniti, D.; Townsend, B.