A charge-coupled device photometric study of south hemispheric contact binary AE Phoenicis

The complete charge-coupled device light curves in B, V, R, and I bands of the short-period binary system, AE Phe, are presented. It is found that the light curves of AE Phe belong to typical EW-type light variation. Photometric solutions were derived by using the 2003 version of the Wilson–Devinney code. It showed that AE Phe is a Wsubtype shallow-contact system (f = 14.6%(±0.5%)) with a mass ratio of q = 2.5491(±0.0092). The temperature difference between the two components is 227 K. Analysis of the O − C curve suggests that the period of AE Phe shows a long-term continuous increase at a rate of dP /dt = +6.17(±0.44) × 10−8 days year−1. The longterm period increase, the marginal-contact configuration, and the astrophysical parameters of the binary system, all suggest that it is a shallow-contact binary undergoing a thermal relaxation oscillation evolving into a detached binary.Fil: He, J. J.. Chinese Academy of Sciences; República de ChinaFil: Qian, S. B.. Chinese Academy of Sciences; República de ChinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Fariña, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

A Close-in Substellar Object Orbiting the sdOB-type Eclipsing-Binary System NSVS14256825

NSVS 14256825 is the second sdOB + dM eclipsing binary systems with anorbital period of 2.65 hours. The special binary was reported to contain circumbinary planets or brown dwarfs by using the timing method. However, different results were derived by different authors because of the insufficient coverage of eclipse timings. Since 2008, we have monitored this binary for about 10 years by using several telescopes and 84 new times of light minimum in high precision were obtained. It is found that the O-C curve is increasing recently and it shows a cyclic variation with a period of 8.83 years and amplitude of 46.31 seconds. The cyclic change cannot be explained by magnetic activity cycles of the red-dwarf component because the required energy is much larger than that radiated by this component in one whole period. This cyclic change detected in NSVS1425 could be explained by the light-travel time effect via the presence of a third body. The lowest mass of the third body is determined as 14.15 Mjup that is in the transition between planets and brown dwarfs. The substellar object is orbiting around this evolved binary at an orbital separation around 3 AU with an eccentricity of 0.12. These results indicate that NSVS 14256825 is the first sdOB-type eclipsing binary consisting of a hierarchical substellar object. The detection of a close-in substellar companion to NSVS 14256825 will provide some insights on the formation and evolution of sdOB-type binaries and their companions.Fil: Zhu, Li-Ying. Yunnan Observatories, Chinese Academy Of Sciences; ChinaFil: Qian, Sheng Bang. Yunnan Observatories, Chinese Academy Of Sciences; ChinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Wang, Zhi Hua. Yunnan Observatories, Chinese Academy Of Sciences; ChinaFil: Li, Lin Jia. Yunnan Observatories, Chinese Academy Of Sciences; Chin

Photometric study of three ultrashort-period contact binaries

We carried out high-precision photometric observations of three eclipsing ultrashort-period contact binaries (USPCBs). Theoretical models were fitted to the light curves by means of the Wilson-Devinney code. The solutions suggest that the three targets have evolved to a contact phase. The photometric results are as follows: (a) 1SWASP J030749.87−365201.7, q= 0.439 ± 0.003 , f= 0.0 ± 3.6 % ; (b) 1SWASP J213252.93−441822.6, q= 0.560 ± 0.003 , f= 14.2 ± 1.9 % ; (c) 1SWASP J200059.78+054408.9, q= 0.436 ± 0.008 , f= 58.4 ± 1.8 %. The light curves show O’Connell effects, which can be modeled by the assumed cool spots. The cool spots models are strongly supported by the night-to-night variations in the I-band light curves of 1SWASP J030749.87−365201.7. For a comparative study, we collected the whole set of 28 well-studied USPCBs with P 50 %). Generally, contact binaries with deep fill-out factors are going to merge, but it is believed that USPCBs have just evolved to a contact phase. Hence, the deep USPCB 1SWASP J200059.78+054408.9 seems to be a contradiction, making it very interesting. Particularly, 1SWASP J030749.87−365201.7 is a zero contact binary in thermal equilibrium, implying that it should be a turn-off sample as predicted by the thermal relaxation oscillation (TRO) theory.Fil: Liu, L.. Chinese Academy of Sciences; República de ChinaFil: Qian, S. B.. Chinese Academy of Sciences; República de ChinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Essam, A.. National Research Institute of Astronomy and Geophysics; EgiptoFil: El Sadek, M. A.. National Research Institute of Astronomy and Geophysics; EgiptoFil: Xiong, X.. Chinese Academy of Sciences; República de Chin

V606 Cen: A Newly Formed Massive Contact Binary in a Hierarchical Triple System

V606 Centauri (V606 Cen) is an early B-type close binary with an orbital period of 1.4950935 days, and its complete light curves are very difficult to observe on the ground. By analyzing the continuous light curve obtained by TESS, we found that it is a marginal contact binary with a very low fill-out factor of about 2%. The O - C diagram of V606 Cen is constructed for the first time based on 118.8 yr of eclipse times. The O - C diagram has been found to show a downward parabolic change together with a cyclic oscillation with a semiamplitude of 0.0545 days and a period of 88.3 yr. The downward parabolic variation reveals a linear period decrease at a rate of dP/dt = -2.08 × 10-7 days yr-1 that can be explained by the mass transfer from the more massive component to the less massive one. Both the marginal contact configuration and the continuous period decrease suggest that V606 Cen is a newly formed contact binary via Case A mass transfer. The cyclic change in the O - C diagram can be explained by the light-travel time effect via the presence of a third body. The lowest mass of the tertiary companion is determined to be M 3 = 4.51 (±0.43) M o˙ and the tertiary is orbiting around the central eclipsing binary in a nearly circular orbit (e = 0.33). All of the results indicate that V606 Cen is a newly formed massive contact binary in a hierarchical triple system.Fil: Li, F. X.. Chinese Academy of Sciences; República de China. Yunnan Observatories; China. Chinese Academy of Sciences; República de ChinaFil: Liao, W. P.. Yunnan Observatories; China. Chinese Academy of Sciences; República de ChinaFil: Qian, S. B.. Yunnan Observatories; China. Chinese Academy of Sciences; República de ChinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Zhang, J.. Chinese Academy of Sciences; República de China. Yunnan Observatories; ChinaFil: Zhao, E. G.. Chinese Academy of Sciences; República de China. Yunnan Observatories; Chin

Planet-star interactions with precise transit timing: II. The radial-velocity tides and a tighter constraint on the orbital decay rate in the WASP-18 system

From its discovery, the WASP-18 system with its massive transiting planet on a tight orbit was identified as a unique laboratory for studies on tidal planet-star interactions. In an analysis of Doppler data, which include five new measurements obtained with the HIRES/Keck-I instrument between 2012 and 2018, we show that the radial velocity signal of the photosphere following the planetary tidal potential can be distilled for the host star. Its amplitude is in agreement with both theoretical predictions of the equilibriumtide approximation and an ellipsoidalmodulation observed in an orbital phase curve. Assuming a circular orbit, we refine system parameters using photometric time series from TESS. With a new ground-based photometric observation, we extend the span of transit timing observations to 28 yr in order to probe the rate of the orbital period shortening. Since we found no departure from a constant-period model, we conclude that the modified tidal quality parameter of the host star must be greater than 3.9×106with 95% confidence. This result is in line with conclusions drawn from studies of the population of hot Jupiters, predicting that the efficiency of tidal dissipation is 1 or 2 orders of magnitude weaker. As the WASP-18 system is one of the prime candidates for detection of orbital decay, further timing observations are expected to push the boundaries of our knowledge on stellar interiors.Fil: Maciejewski, G.. Nicolaus Copernicus University; PoloniaFil: Knutson, H. A.. California Institute of Technology; Estados UnidosFil: Howard, A. W.. University of Hawaii; Estados UnidosFil: Isaacson, H.. University of California at Berkeley; Estados UnidosFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Di Sisto, Romina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Migaszewski, C.. Nicolaus Copernicus University; Poloni

Rapid Decreasing in the Orbital Period of the Detached White Dwarf?main Sequence Binary SDSS J143547.87+373338.5

SDSS J143547.87+373338.5 is a detached eclipsing binary that contains a white dwarf with a mass of 0.5 M⊙ and a fully convective star with a mass of 0.21 M⊙. The eclipsing binary was monitored photometrically from 2009 March 24 to 2015 April 10, by using two 2.4-m telescopes in China and in Thailand. The changes in the orbital period are analyzed based on eight newly determined eclipse times together with those compiled from the literature. It is found that the observed?calculated (O?C) diagram shows a downward parabolic change that reveals a continuous period decrease at a rate of dot{P}=-8.04× {10}-11 s s‑1. According to the standard theory of cataclysmic variables, angular momentum loss (AML) via magnetic braking (MB) is stopped for fully convective stars. However, this period decrease is too large to be caused by AML via gravitational radiation (GR), indicating that there could be some extra source of AML beyond GR, but the predicted mass-loss rates from MB seem unrealistically large. The other possibility is that the O?C diagram may show a cyclic oscillation with a period of 7.72 years and a small amplitude of 0.ͩ000525. The cyclic change can be explained as the light-travel-time effect via the presence of a third body because the required energy for the magnetic activity cycle is much larger than that radiated from the secondary in a whole cycle. The mass of the potential third body is determined to be {M}3{sin}{i}prime =0.0189(+/- 0.0016) M⊙ when a total mass of 0.71 M⊙ for SDSS J143547.87+373338.5 is adopted. For orbital inclinations {i}prime ≥slant 15uildrel{circ}over{.} 9, it would be below the stable hydrogen-burning limit of M3 ∼ 0.072 M⊙, and thus the third body would be a brown dwarf.Fil: Qian, S. B.. Chinese Academy of Sciences; República de ChinaFil: Han, Z. T.. Chinese Academy of Sciences; República de ChinaFil: Soonthornthum, B.. National Astronomical Research Institute of Thailand; TailandiaFil: Zhu, L. Y.. Chinese Academy of Sciences; República de ChinaFil: He, J. J.. Chinese Academy of Sciences; República de ChinaFil: Rattanasoon, S.. National Astronomical Research Institute of Thailand; TailandiaFil: Aukkaravittayapun, S.. National Astronomical Research Institute of Thailand; TailandiaFil: Liao, W. P.. Chinese Academy of Sciences; República de ChinaFil: Zhao, E. G.. Chinese Academy of Sciences; República de ChinaFil: Zhang, J.. Chinese Academy of Sciences; República de ChinaFil: Fernandez Lajus, Eduardo Eusebio. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica la Plata; Argentin

BVRI photometric observations, light curve solutions and orbital period analysis of BF Pav

A new ephemeris, period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this study. Light curves of the system taken in BVRI filters from two observatories, in Australia and Argentina, were modeled using the Wilson-Devinney code. The results of this analysis demonstrate that BF Pav is a contact binary system with a photometric mass ratio q = 1.460 ± 0.014, a fillout factor f = 12.5%, an inclination of 87.97 ± 0.45 deg and a cold spot on the secondary component. By applying the distance modulus formula, the distance of BF Pav was calculated to be d = 268 ± 18 pc which is in good agreement with the Gaia EDR3 distance. We obtain an orbital period increase at a rate of 0.142 s century−1 due to a quadratic trend in the O − C diagram. Also, an alternative sudden period jump probably occurred which could be interpreted as a rapid mass transfer from the lower mass star to its companion of about ∆M = 2.45×10−6 M. Furthermore, there is an oscillatory behavior with a period of 18.3 ± 0.3 yr. Since BF Pav does not seem to have significant magnetic activity, this behavior could be interpreted as the light-time effect caused by an undetected third body in this system. In this case, the probability for the third body to be a low mass star with M ≥ 0.075 M or a brown dwarf is 5.4% and 94.6% respectively. If we assume i0 = 90◦, a3 = 8.04 ± 0.33 AU. The mass of the secondary component was also determined following two different methods which result close to each other.Fil: Poro, Atila. The International Occultation Timing Association Middle East section; IránFil: Alicavus, Fahri. Canakkale Onsekiz Mart University; TurquíaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Davoudi, Fatemeh. The International Occultation Timing Association Middle East section; IránFil: MirshafieKhozani, PegahSadat. The International Occultation Timing Association Middle East section; IránFil: Blackford, Mark G.. Congarinni Observatory; AustraliaFil: Budding, Edwin. Université du Québec a Montreal; CanadáFil: Jalalabadi, Behjat Zarei. Carter Observatory; Nueva ZelandaFil: Rahimi, Jabar. The International Occultation Timing Association Middle; IránFil: Farahani, Farzaneh Ahangarani. The International Occultation Timing Association Middle; Irá

Changes in the surface irradiance during the total solar eclipse 2020 in Valcheta, Argentina

On December 14, 2020, southern South America experienced a total solar eclipse close to the solar noon. The path of totality, about 90 km wide, extended over the continental region from the Chilean west coast to the Argentine east coast, passing through the provinces of Neuquén, Río Negro and the extreme south of Buenos Aires. In order to study the effects on the atmosphere produced by the total eclipse, the Servicio Meteorológico Nacional Argentino (SMN) and Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF) carried out a surface radiometric monitoring campaign in Valcheta (40.69°S; 66.15°W), Río Ne-gro, Argentina. In this work, we explore the global surface solar irradiance on a horizontal plane (GHI) with the main objective of quantifying the changes in this parameter for cloudy and clear sky atmospheric conditions, combining ground-based measurements and modeling. A solar limb-darkening function was successfully im-plemented in the calculation of the irradiance at the top of the atmosphere (TOA) during the eclipse. We estimated a significant GHI attenuation of 41 % between the first (C1) and last (C4) contacts of eclipse compared to similar atmospheric conditions without the total eclipse, which represent a daily reduction of 12 %. In terms of irradiation, a reduction of 3360.1 KJ/m2 was calculated.Fil: Orte, Pablo Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; ArgentinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Di Sisto, Romina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; Argentina. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Lusi, Anabela Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Nicora, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; ArgentinaFil: D'elia, Raul Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Verstraeten, Federico. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Papandrea, Sebastián Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Carmona, Facundo. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff"; Argentin

RW Doradus: A solar-type shallow contact binary with a new orbital period investigation

New CCD photometric light curves of the short-period (P = 0.285 d) eclipsing binary RW Dor are presented. The observations were performed with the PROMPT-8 robotic telescope at CTIO in Chile between 2015 March and 2017 March. Other eclipse timings were obtained from the 2.15 m JS telescope at CASLEO, San Juan, Argentina in 2011 December. Based on a light curve analysis, it is found that RW Dor is a W-type shallow contact binary with a fill-out factor f ∼ 11% and a high mass ratio q ∼ 1.587 (1/q = 0.63), where the hotter component is the less massive one (M1 ∼ 0.52 M and M2 ∼ 0.82 M). For orbital-period investigation, 15 new eclipse times and those previously published were compiled. O − C analysis with very weak evidence suggests that a long-term decrease in period with a rate of dP/dt = −9.61 × 10−9 d yr−1 is superimposed on a cyclic variation(A3 = 0.0054 d and P3 = 49.9 yr). The long-term decrease can be interpreted as mass transfer from the more massive component to the less massive one, or combined with angular momentum loss via magnetic braking. In addition, the marginal contact phase, high mass ratio (1/q > 0.4), and long-term decrease in period all suggest that RW Dor is a newly formed contact binary via Case A mass transfer, and it will evolve into a deepernormal contact binary. If the cyclic change is correct, the light travel-time effect via the presence of a cool third body will be a more plausible explanation for this.Fil: Sarotsakulchai, Thawicharat. University of Chinese Academy of Sciences; China. National Astronomical Research Institute of Thailand; Tailandia. Chinese Academy of Sciences; República de ChinaFil: Qian, Sheng Bang. Chinese Academy of Sciences; República de China. University of Chinese Academy of Sciences; ChinaFil: Soonthornthum, Boonrucksar. National Astronomical Research Institute of Thailand; TailandiaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Liu, Nian Ping. Chinese Academy of Sciences; República de ChinaFil: Zhou, Xiao. Chinese Academy of Sciences; República de ChinaFil: Zhang, Jia. Chinese Academy of Sciences; República de ChinaFil: Liao, Wen Ping. Chinese Academy of Sciences; República de ChinaFil: Reichart, Daniel E.. University of North Carolina; Estados UnidosFil: Haislip, Joshua B.. University of North Carolina; Estados UnidosFil: Kouprianov, Vladimir V.. University of North Carolina; Estados UnidosFil: Poshyachinda, Saran. National Astronomical Research Institute of Thailand; Tailandi

Multi-band behaviour of the TeV blazar PG 1553+113 in optical range on diverse timescales. Flux and spectral variations

Context. The TeV BL Lac object PG1553+113 is one of the primary candidates for a binary supermassive black hole system.Aims. We study the flux and spectral variability of PG1553+113 on intra-night to long-term timescales using (i) BVRI data collected over 76 nights from January 2016 to August 2019 involving nine optical telescopes and (ii) historical VR data (including ours) obtained for the period from 2005 to 2019.Methods. We analysed the light curves using various statistical tests, fitting and cross-correlation techniques, and methods for the search for periodicity. We examined the colour-magnitude diagrams before and after the corresponding light curves were corrected for the long-term variations.Results. Our intra-night monitoring, supplemented with literature data, result in a low duty cycle of ∼(10?18)%. In April 2019, we recorded a flare, which marks the brightest state of PG1553+113 for the period from 2005 to 2019: R ≃ 13.2mag. This flare is found to show a clockwise spectral hysteresis loop on its VR colour-magnitude diagram and a time lag in the sense that the V-band variations lead the R-band ones.We obtain estimates of the radius, the magnetic field strength, and the electron energy that characterize the emission region related to the flare.We find a median period of (2.21±0.04) years using the historical light curves. In addition, we detect a secondary period of about 210 days using the historical light curves corrected for the long-term variations. We briefly discuss the possible origin of this period.Fil: Agarwal, A.. Indian Institute Of Astrophysics; India. Raman Research Institute; IndiaFil: Mihov, B.. Institute Of Astronomy And Nao; BulgariaFil: Andruchow, Ileana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Cellone, Sergio Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Anupama, G. C.. Indian Institute Of Astrophysics; IndiaFil: Agrawal, V.. Embibe; IndiaFil: Zola, S.. Jagiellonian University; PoloniaFil: Slavcheva Mihova, L.. Institute Of Astronomy And Nao; BulgariaFil: Özdönmez, A.. Ataturk University; TurquíaFil: Ege, E.. Istanbul University; TurquíaFil: Raj, A.. University Enclave; IndiaFil: Mammana, Luis Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Zibecchi, Lorena Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentin