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Light Curve Analysis of the AP Dor Binary system using Ground-based and Tess Observations

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天文和天体物理学研究:英文版 2023年第9期23卷 114-128页

作者： A.Poro e.fernández-laj.s M.Madani G.sabbaghian F.Nasrollahzadeh F.Jahediparizi Astronomy Department of the Raderon AI Lab. BurnabyBCCanada Instituto de Astrofísica de La Plata(CCT La Plata-CONICeT-UNLP) La PlataArgentina Facultad de Ciencias Astronómicas y Geofísicas Universidad Nacional de La PlataPaseo del BosqueB1900FWALa PlataArgentina BsN Project Transiting Exoplanets DepartmentTehranIran Department of Physics Shahid Bahonar University of KermanKermanIran

The short-period eclipsing binary AP Dor’s first in-depth and multiband photometric solutions are *** made use of our eight nights of ground-based opportunity at a southern hemisphere observatory,and twelve sectors of Tess *** extracted eight and 1322 minima from our observations and Tess,*** suggest a new linear ephemeris based on the trend of orbital period variations using the Markov chain Monte Carlo(MCMC)*** PHysics Of eclipsing Binaries(PHOeBe)Python code and the MCMC approach were utilized for the light curve *** system did not require a starspot for the light curve *** calculated the absolute parameters of the system by applying the Gaia DR3 parallax *** orbital angular momentum(J_(0))of AP Dor indicates that this system is located in a region corresponding to contact *** to our results,this system is an overcontact binary system with a mass ratio of 0.584,a fillout factor of 48%,and an inclination of 53°.The positions of component stars in the AP Dor system on the Hertzsprung–Russell diagram are found.

关键词： (stars )binaries eclipsing-methods observational-stars individual(AP Dor)

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

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Research in Astronomy and Astrophysics 2021年第8期21卷 193-202页

作者： Atila Poro Fahri Alicavus eduardo fernández-laj.s Fatemeh Davoudi Pegahsadat MirshafieKhozani Mark G.Blackford edwin Budding Behjat Zarei Jalalabadi Jabar Rahimi Farzaneh Ahangarani Farahani The International Occultation Timing Association Middle east section Iran Astronomy Department of the Raderon Lab BurnabyBCCanada Canakkale Onsekiz Mart University Faculty of Arts and SciencesDepartment of Physics17020CanakkaleTurkey Canakkale Onsekiz Mart University Astrophysics Research Center and Ulupnar Observatory17020CanakkaleTurkey Instituto de Astrofisica de La Plata(CCT La Plata-CONICeT-UNLP) La PlataArgentina Facultad de Ciencias Astronomicas y Geofisicas Universidad Nacional de La PlataPaseo del BosqueB1900FWALa PlataArgentina Variable stars south(Vss) Congarinni ObservatoryCongarinniNSW2447Australia Carter Observatory 40 Salamanca RdKelburnWellington 6012New Zealand

A new ephemeris,period change analysis and light curve modeling of the W UMa-type eclipsing binary BF Pav are presented in this *** curves of the system taken in BVRI filters from two observatories,in Australia and Argentina,were modeled using the Wilson-Devinney *** 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 *** 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 *** obtain an orbital period increase at a rate of 0.142 s century-1 due to a quadratic trend in the O-C ***,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 ΔM=2.45 × 10-6 M⊙.Furthermore,there is an oscillatory behavior with a period of 18.3±0.3 *** 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 *** 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% *** we assume i’=90°,a3=8.04±0.33 *** mass of the secondary component was also determined following two different methods which result close to each other.

关键词： techniques:photometric binaries:eclipsing stars:individual(BF Pav)

Oxidized organic molecules in the tropical free troposphere over Amazonia

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National science Review 2024年第1期11卷 174-184页

作者： Qiaozhi Zha Diego Aliaga Radovan Krejci Victoria A.sinclair Cheng Wu Giancarlo Ciarelli Wiebke scholz Liine Heikkinen eva Partoll Yvette Gramlich Wei Huang Markus Leiminger Joonas enroth Otso Per?kyl? Runlong Cai Xuemeng Chen Alkuin Maximilian Koenig fernando Velarde Isabel Moreno Tuukka Pet?j? Paulo Artaxo Paolo laj Armin Hansel samara Carbone Markku Kulmala Marcos Andrade Douglas Worsnop Claudia Mohr Federico Bianchi Institute for Atmospheric and earth system Research/Physics University of Helsinki Joint International Research Laboratory of Atmospheric and earth system sciences Nanjing University Department of environmental science & Bolin Centre for Climate Research Stockholm University Department of Chemistry and Molecular Biology University of Gothenburg Institute for Ion and Applied Physics University of Innsbruck Ionicon Analytik GmbH Laboratory for Atmospheric Physics Institute for Physics Research Universidad Mayor de San Andrés Institute of Physics University of Sao Paulo Institute for Geosciences and environmental Research (IGe) University of Grenoble Alpes Agrarian sciences Institute Federal University of Uberl?ndia Beijing Advanced Innovation Center for soft Matter science and engineering Beijing University of Chemical Technology Department of Atmospheric and Oceanic sciences University of Maryland Aerodyne Research Inc. Department of environmental system science ETH Zürich switzerland and Laboratory of Atmospheric Chemistry Paul Scherrer Institute

New particle formation(NPF) in the tropical free troposphere(FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules(OOMs)produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 m above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4–5 carbon atoms, in both gas-phase and particle-phase(in terms of mass contribution) measurements in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to NPF, at least the growth of newly formed nanoparticles, in the tropical FT on a continental scale. Thus, our study is a fundamental and significant step in understanding the aerosol formation process in the tropical FT.

关键词： oxidized organic molecules tropical aerosol formation Amazon free troposphere

High black carbon and ozone concentrations during pollution transport in the Himalayas: Five years of continuous observations at NCO-P global GAW station

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Journal of environmental sciences 2013年第8期25卷 1618-1625页

作者： A. Marinoni P. Cristofanelli P. laj R. Duchi D. Putero F. Calzolari T. C. Landi e. Vuillermoz M. Maione P. Bonasoni Institute for Atmospheric sciences and Climate National Research Council of Italy Laboratoire de Glaciologie et Géophysique de l'environnement Université Grenoble 1 CNRS eV-K2-CNR Committee Urbino University DiSBeF

To study the influence of polluted air-mass transport carrying ozone （O3） and black carbon （BC） in the high Himalayas, since March 2006 the Nepal Climate Observatory at Pyramid （NCO-P） GAW-WMO global station （Nepal, 5079 m a.s.l.） is operative. During the first 5-year measurements, the O3 and BC concentrations have shown a mean value of 48 ± 12 ppb （± standard deviation） and 208 ± 374 ng/m3, respectively. Both O3 and BC showed well defined seasonal cycles with maxima during pre-monsoon （O3 ： 61.3 ± 7.7 ppbV; BC： 444 ± 433 ng/m3） and minima during the summer monsoon （O3 ： 40.1 ± 12.4 ppbV; BC： 64 ± 101 ng/m3）. The analysis of the days characterised by the presence of a significant BC increase with respect to the typical seasonal cycle identified 156 days affected by ＂acute＂ pollution events, corresponding to 9.1% of the entire data-set. such events mostly occur in the pre-monsoon period, when the O3 diurnal variability is strongly related to the transport of polluted air-mass rich on BC. On average, these ＂acute＂ pollution events were characterised by dramatic increases of BC （352%） and O3 （29%） levels compared with the remaining days.

关键词： ozone black carbon Himalayas pollution biomass burning troposphere