TY - JOUR AU - Moór, Attila AU - Ábrahám, Péter AU - Su, K Y L AU - Henning, T AU - Marino, S AU - Chen, Lei AU - Kóspál, Ágnes AU - Pawellek, Nicole AU - Varga, József AU - Vida, Krisztián TI - Abundant sub-micron grains revealed in newly discovered extreme debris discs JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY J2 - MON NOT R ASTRON SOC VL - 528 PY - 2024 IS - 3 SP - 4528 EP - 4546 PG - 19 SN - 0035-8711 DO - 10.1093/mnras/stae155 UR - https://m2.mtmt.hu/api/publication/34566634 ID - 34566634 N1 - Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences, Konkoly-Thege Miklós út 15-17, Budapest, H-1121, Hungary CSFK, MTA Centre of Excellence, Konkoly Thege Miklós út 15-17., Budapest, H-1121, Hungary ELTE Eötvös Loránd University, Institute of Physics, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary Department of Astrophysics, University of Vienna, Türkenschanzstraße 17, Vienna, 1180, Austria Department of Astronomy, Steward Observatory, The University of Arizona, Tucson, AZ 85721-0009, United States Max-Planck-Institut für Astronomie, Königstuhl 17, Heidelberg, D-69117, Germany Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, EX4 4QL, United Kingdom Export Date: 18 April 2024 CODEN: MNRAA Correspondence Address: Moór, A.; Konkoly Observatory, Konkoly-Thege Miklós út 15-17, Hungary; email: moor@konkoly.hu AB - Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results of a mini-survey we conducted with the aim to increase the number of known EDDs, investigate the presence of solid-state features around 10 μm in eight EDDs, and classify them into the silica or silicate dominated groups. We identify four new EDDs and derive their fundamental properties. For these, and for four other previously known discs, we study the spectral energy distribution around 10 μm by means of VLT/VISIR photometryin three narrow-band filters and conclude that all eight objects likely exhibit solid-state emission features from sub-micron grains. We find that four discs probably belong to the silicate dominated subgroup. Considering the age distribution of the entire EDD sample, we find that their incidence begins to decrease only after 300 Myr, suggesting that the earlier common picture that these objects are related to the formation of rocky planets may not be exclusive, and that other processes may be involved for older objects (≳100 Myr). Because most of the older EDD systems have wide, eccentric companions, we suggest that binarity may play a role in triggering late giant collisions. LA - English DB - MTMT ER - TY - CONF AU - Raetz, Stefanie AU - Stelzer, Beate AU - Vicanek, Martinez Tobias AU - Bruno, Giovanni AU - Vida, Krisztián AU - Feliz, Dax AU - Stassun, Keivan TI - Stellar flares with PLATO T2 - PLATO Stellar Science Conference 2023 PY - 2023 DO - 10.5281/zenodo.8143624 UR - https://m2.mtmt.hu/api/publication/34718724 ID - 34718724 AB - Stellar flares are powerful localized eruptions caused by magnetic reconnection events in a star's magnetosphere that can be seen across the entire electromagnetic spectrum. Over short timescales of minutes to a few hours, they emit energies up to 10^38 erg. Flares are important diagnostics for our understanding of coronal physics as well as the evolution of planetary atmospheres. While flares with energies >10^34 erg can lead to an erosion of the ozone layer of the planet's atmosphere when they occur frequently enough, a minimum flare frequency and energy might be required to trigger chemical reactions that are necessary for the development of life. The PLATO mission with its unprecedented precision, short cadence and long observational baseline, is ideally suited to study stellar white-light flares in up to now unrivaled detail. Flares will be identified within the PLATO pipeline MSAP1 with a code developed by the PLATO WP 123 700 ("Stellar flares") both in order to remove stellar variability from the light curves and to extract astrophysically important information. The first prototype of the code was already delivered to the PDC. In this talk I provide a brief summary of the work carried out in the PLATO WP and I will show examples of applications of the flare detection algorithm we develop for MSAP1 to selected stellar samples, e.g. the TESS HZCat M dwarf sample or the Kepler Superflare sample. Furthermore, I will show how the derived flare properties help to estimate the effects of flaring on the habitability of exoplanets. LA - English DB - MTMT ER - TY - CHAP AU - Bódi, Attila AU - Vida, Krisztián ED - Bufano, F. ED - Riggi, S. ED - Sciacca, E. ED - Schilliro, F. TI - Finding Stellar Flares with Recurrent Deep Neural Networks T2 - 1st International Conference on Machine Learning for Astrophysics, ML4ASTRO 2022 VL - 60 PB - Springer Science+Business Media SN - 9783031341663 T3 - Astrophysics and Space Science Proceedings, ISSN 1570-6591 ; 60. PY - 2023 SP - 105 EP - 109 PG - 5 DO - 10.1007/978-3-031-34167-0_21 UR - https://m2.mtmt.hu/api/publication/34683543 ID - 34683543 N1 - Export Date: 25 February 2024; Cited By: 0; Correspondence Address: A. Bódi; Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network, Budapest, Hungary; email: bodi.attila@csfk.org LA - English DB - MTMT ER - TY - JOUR AU - Ertini, K. AU - Folatelli, G. AU - Martinez, L. AU - Bersten, M. C. AU - Anderson, J. P. AU - Ashall, C. AU - Baron, E. AU - Bose, S. AU - Brown, P. J. AU - Burns, C. AU - DerKacy, J. M. AU - Ferrari, L. AU - Galbany, L. AU - Hsiao, E. AU - Kumar, S. AU - Lu, J. AU - Mazzali, P. AU - Morrell, N. AU - Orellana, M. AU - Pessi, P. J. AU - Phillips, M. M. AU - Piro, A. L. AU - Polin, A. AU - Shahbandeh, M. AU - Shappee, B. J. AU - Stritzinger, M. AU - Suntzeff, N. B. AU - Tucker, M. AU - Elias-Rosa, N. AU - Kuncarayakti, H. AU - Gutiérrez, C. P. AU - Kozyreva, A. AU - Müller-Bravo, T. E. AU - Chen, T. -W. AU - Hinkle, J. T. AU - Payne, A. V. AU - Székely, Péter AU - Szalai, Tamás AU - Barna, Barnabás AU - Könyves-Tóth, Réka AU - Bánhidi, D. AU - Bíró, I. B. AU - Csányi, István AU - Kriskovics, Levente AU - Pál, András AU - Szabó, Zs AU - Szakáts, Róbert AU - Vida, Krisztián AU - Vinkó, József AU - Gromadzki, M. AU - Harvey, L. AU - Nicholl, M. AU - Paraskeva, E. AU - Young, D. R. AU - Englert, B. TI - SN 2021gno: a calcium-rich transient with double-peaked light curves JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY J2 - MON NOT R ASTRON SOC VL - 526 PY - 2023 IS - 1 SP - 279 EP - 298 PG - 20 SN - 0035-8711 DO - 10.1093/mnras/stad2705 UR - https://m2.mtmt.hu/api/publication/34232492 ID - 34232492 N1 - Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, La Plata, B1900FWA, Argentina Instituto de Astrofísica de La Plata (IALP), CCT-CONICET-UNLP, Paseo del Bosque S/N, La Plata, B1900FWA, Argentina Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Chiba, Kashiwa, 277-8583, Japan Universidad Nacional de Río Negro. Sede Andina, Mitre 630, Bariloche, 8400, Argentina European Southern Observatory, Alonso de Córdova 3107, Casilla 19, Vitacura, Santiago, 8320000, Chile Millennium Institute of Astrophysics MAS, Nuncio Monsenor Sotero Sanz 100, Off. 104, Providencia, Santiago, 8320000, Chile Department of Physics, Virginia Tech, Blacksburg, VA 24061, United States Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks, Norman, OK 73019-2061, United States Hamburger Sternwarte, Gojenbergsweg 112, Hamburg, D-21029, Germany Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210, United States Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210, United States Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A&M University, 4242 TAMU, College Station, TX 77845, United States The Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101, United States Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans, s/n, Barcelona, E-08193, Spain Institut d'Estudis Espacials de Catalunya (IEEC), Barcelona, E-08034, Spain Department of Physics, Florida State University, 77 Chieftain Way, Tallahassee, FL 32306, United States Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool, L3 5RF, United Kingdom Max-Planck-Institut für Astrophysik, Karl-Schwarzschild Str 1, Garching, D-85748, Germany Carnegie Observatories, Las Campanas Observatory, Casilla 601, La Serena, 1700000, Chile Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Capital FederalC1425FQD, Argentina TAPIR, Walter Burke Institute for Theoretical Physics, 350-17, Caltech, Pasadena, CA 91125, United States Institute for Astronomy, University of Hawai'i at Manoa, 2680 Woodlawn Dr, Honolulu, HI 96822, United States Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, DK-8000, Denmark INAF - Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, Padova, I-35122, Italy Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Turku, FI-20014, Finland Heidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, Heidelberg, D-69118, Germany The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, Stockholm, SE-10691, Sweden Department of Experimental Physics, Institute of Physics, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary ELKH-SZTE Stellar Astrophysics Research Group, Szegediút, Kt. 766, Baja, H-6500, Hungary Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Konkoly Thege Miklós út 15-17, Budapest, H-1121, Hungary CSFK, MTA Centre of Excellence, Konkoly Thege Miklós út 15-17, Budapest, H-1121, Hungary Gothard Astrophysical Observatory, ELTE Eötvös Loránd University, Szombathely, H-9400, Hungary Baja Astronomical Observatory of University of Szeged, Szegedi út, Kt. 766, Baja, H-6500, Hungary Eötvös Loránd University, Department of Astronomy, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary Institute of Physics, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02109, United States Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, Bonn, D-53121, Germany Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom Department of Optics & Quantum Electronics, Institute of Physics, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, Warszawa, PL-00-478, Poland School of Physics, Trinity College Dublin, The University of Dublin, Dublin, Ireland Birmingham Institute for Gravitational Wave Astronomy and School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, United Kingdom Department of Physics and Astronomy, University of California, One Shields Avenue, Davis, CA 95616, United States Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, United Kingdom Combate de los Pozos 1028, C1222AAL Ciudad Autónoma de Buenos Aires, Argentina Export Date: 22 March 2024 CODEN: MNRAA Correspondence Address: Ertini, K.; Facultad de Ciencias Astronómicas y Geofísicas, Paseo del Bosque S/N, Argentina; email: keilaertini@gmail.com AB - We present extensive ultraviolet (UV) and optical photometric and optical spectroscopic follow-up of supernova (SN) 2021gno by the 'Precision Observations of Infant Supernova Explosions' (POISE) project, starting less than 2 d after the explosion. Given its intermediate luminosity, fast photometric evolution, and quick transition to the nebular phase with spectra dominated by [Ca II] lines, SN 2021gno belongs to the small family of Calcium-rich transients. Moreover, it shows double-peaked light curves, a phenomenon shared with only four other Calcium-rich events. The projected distance from the centre of the host galaxy is not as large as other objects in this family. The initial optical light-curve peaks coincide with a very quick decline of the UV flux, indicating a fast initial cooling phase. Through hydrodynamical modelling of the bolometric light curve and line velocity evolution, we found that the observations are compatible with the explosion of a highly stripped massive star with an ejecta mass of $0.8\\, M_\\odot$ and a 56Ni mass of 0.024 M⊙. The initial cooling phase (first light-curve peak) is explained by the presence of an extended circumstellar material comprising ~$10^{-2}\\, {\\rm M}_{\\odot }$ with an extension of $1100\\, R_{\\odot }$. We discuss if hydrogen features are present in both maximum-light and nebular spectra, and their implications in terms of the proposed progenitor scenarios for Calcium-rich transients. LA - English DB - MTMT ER - TY - JOUR AU - Barna, Barnabás AU - Nagy, Andrea AU - Bora, Zs. AU - Czavalinga, Donát Róbert AU - Könyves-Tóth, Réka AU - Szalai, Tamás AU - Székely, Péter AU - Zsíros, Szanna AU - Banhidi, D. AU - Biro, I. B. AU - Csanyi, I. AU - Kriskovics, Levente AU - Pál, András AU - Szabo, Zs. M. AU - Szakáts, Róbert AU - Vida, Krisztián AU - Bodola, Zsófia Réka AU - Vinkó, József TI - Three is the magic number: Distance measurement of NGC 3147 using SN 2021hpr and its siblings JF - ASTRONOMY & ASTROPHYSICS J2 - ASTRON ASTROPHYS VL - 677 PY - 2023 PG - 16 SN - 0004-6361 DO - 10.1051/0004-6361/202346395 UR - https://m2.mtmt.hu/api/publication/34221293 ID - 34221293 AB - Context. The nearby spiral galaxy NGC 3147 hosted three Type Ia supernovae (SNe Ia) in the past decades that have been the subjects of intense follow-up observations. Simultaneous analysis of their data provides a unique opportunity for testing different methods of light curve fitting and distance estimation.Aims. The detailed optical follow-up of SN 2021hpr allows us to revise the previous distance estimations to NGC 3147 and compare the widely used light curve fitting algorithms to each other. After the combination of the available and newly published data of SN 2021hpr, its physical properties can also be estimated with higher accuracy.Methods. We present and analyse new BVgriz and Swift photometry of SN 2021hpr to constrain its general physical properties. Together with its siblings, SNe 1997bq and 2008fv, we cross-compared the individual distance estimates of these three SNe given by the Spectral Adaptive Lightcurve Template (SALT) code, and we also checked their consistency with the results from the Multi-Color Light Curve Shape (MLCS) code. The early spectral series of SN 2021hpr was also fit with the radiative spectral code TARDIS to verify the explosion properties and constrain the chemical distribution of the outer ejecta.Results. After combining the distance estimates for the three SNe, the mean distance to their host galaxy, NGC 3127, is 42.5 +/- 1.0 Mpc, which matches with the distance inferred by the most up-to-date light curve fitters, SALT3 and BayeSN. We confirm that SN 2021hpr is a Branch-normal Type Ia SN that ejected -1.12 +/- 0.28 M-circle dot from its progenitor white dwarf and synthesized -0.44 +/- 0.14 M-circle dot of radioactive Ni-56. LA - English DB - MTMT ER - TY - JOUR AU - Kriskovics, Levente AU - Kővári, Zsolt AU - Seli, Bálint Attila AU - Oláh, Katalin Ilona AU - Vida, Krisztián AU - Henry, G. W. AU - Granzer, T. AU - Görgei, A. TI - EI Eridani: A star under the influence. The effect of magnetic activity in the short and long term JF - ASTRONOMY & ASTROPHYSICS J2 - ASTRON ASTROPHYS VL - 674 PY - 2023 SN - 0004-6361 DO - 10.1051/0004-6361/202245767 UR - https://m2.mtmt.hu/api/publication/34053151 ID - 34053151 N1 - Funding Agency and Grant Number: Hungarian National Research, Development and Innovation Office [OTKA K-131508, KKP-143986, 2019-2.1.11-TeT-2019-00056]; Bolyai+ [UNKP-22-5-ELTE-1093]; DNew National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund; NASA; NSF; State of Tennessee through its Centers of Excellence Program Funding text: The authors would like to thank Albert Washuettl and the original MUSICOS team for organizing and gathering the data used in this work. The authors acknowledge the Hungarian National Research, Development and Innovation Office grants OTKA K-131508, KKP-143986 (Elvonal), and 2019-2.1.11-TeT-2019-00056. L.K. acknowledges the Hungarian National Research, Development and Innovation Office grant OTKA PD-134784. L.K. and K.V. are Bolyai Janos research Fellows. K.V. is supported by the Bolyai+ grant UNKP-22-5-ELTE-1093, BS is supported by the UNKP-22-3 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. G.W.K. acknowledges long-term support from NASA, NSF, and the State of Tennessee through its Centers of Excellence Program. AB - Context. Homogeneous photometric time series spanning decades provide a unique opportunity to study the long-term cyclic behavior of active spotted stars such as our target EI Eridani. In addition, with ultraprecise space photometry data, it is possible to investigate the accompanying flare activity in detail. However, the rotation period of ≈2 days for EI Eri makes it impossible to achieve time-resolved surface images from a single ground-based observing site. Therefore, for this purpose, spectroscopic data from a multi-site observing campaign are needed. LA - English DB - MTMT ER - TY - GEN AU - Szabo, Z. M. AU - Kóspál, Ágnes AU - Ábrahám, Péter AU - Park, Sunkyung AU - Siwak, Michal AU - Green, J. D. AU - Moór, Attila AU - Pál, András AU - Acosta-Pulido, J. A. AU - Lee, J. -E. AU - Cseh, B. AU - Csornyei, G. AU - Hanyecz, O. AU - Könyves-Tóth, Réka AU - Krezinger, M. AU - Kriskovics, Levente AU - Ordasi, A. AU - Sárneczky, Krisztián AU - Seli, B. AU - Szakáts, Róbert AU - Szing, A. AU - Vida, Krisztián TI - VizieR Online Data Catalog: Opt-to-IR monitoring obs. of V1057 Cyg (Szabo+, 2021) PY - 2023 UR - https://m2.mtmt.hu/api/publication/33729197 ID - 33729197 AB - We performed the majority of our photometric observations in B, V, RC, IC , g', r', and i' filters at the Piszkesteto Mountain Station of Konkoly Observatory (Hungary) between 2005 and 2021. Three telescopes with three slightly different optical systems were used: the 1m Ritchey-Chretien-coude (RCC) telescope, the 60/90/180cm Schmidt telescope and the Astro Systeme Austria AZ800 alt-azimuth direct drive 80cm Ritchey-Chretien (RC80) telescope; see Section 2.1. In addition to our national facilities, we occasionally used other telescopes. On 2006 July 20 and 2012 October 13 we obtained B, V, RJ, and IJ images of V1057 Cyg with the IAC80 telescope of the Instituto de Astrofisica de Canarias located at Teide Observatory (Canary Islands, Spain). During 2019 August-September, in parallel with TESS, we additionally observed V1057 Cyg at the Northern Skies Observatory (NSO). We used the 0.4m telescope equipped with BVI filters. We also observed V1057 Cyg with the 2.56m Nordic Optical Telescope (NOT) at the Roque de los Muchachos Observatory, La Palma, in the Canary Islands (Plan ID 61-414, PI: Zs. M. Szabo). For optical imaging we used the Alhambra Faint Object Spectrograph and Camera (ALFOSC) on 2020 August 17. The Bessel BVR filter set was supplemented by an i interference filter, which is similar to the SLOAN i', but with a slightly longer effective wavelength of λeff=0.789um. We obtained NIR images in the J, H, and Ks bands at six epochs between 2006 July 15 and 2012 October 13 using the 1.52m Telescopio Carlos Sanchez (TCS) at the Teide Observatory. We also used the NOTCam instrument on the NOT on 2020 August 29. See Section 2.3. We obtained a new optical spectrum of V1057 Cyg with the high-resolution FIbre-fed Echelle Spectrograph (FIES) instrument on the NOT on 2020 August 17. We used a fiber with a larger entrance aperture of 2.5", which provided a spectral resolution R=25000, covering the 370-900nm wavelength range. V1057 Cyg was also observed with the Bohyunsan Optical Echelle Spectrograph (BOES) installed on the 1.8m telescope at the Bohyunsan Optical Astronomy Observatory (BOAO). It provides R=30000 in the wavelength range ~400-900nm. The first spectrum was obtained on 2012-September-11 and the last on 2018-December-18. See Section 2.4. On 2020 August 29, we used the NOTCam on the NOT to obtain new NIR spectra of V1057 Cyg and Iot Cyg (A5 V) as our telluric standard star in the JHKs bands. We used the low-resolution camera mode (R=2500). See Section 2.5. On 2018 September 6, we observed V1057 Cyg with the Stratospheric Observatory for Infrared Astronomy (SOFIA) using the Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST). We obtained mid-infrared imaging in a series of short exposures in band F111 (10.6-11.6um) totaling ~30s, a single exposure in F056 (5.6um) for 37s and F077 (7.5-8um) for 42s, and R~100-200 spectra with G063 (5-8um) and G227 (17-27um) (Plan ID 06_062, PI: J. D. Green). See Section 2.6. (2 data files). LA - English DB - MTMT ER - TY - JOUR AU - Oláh, Katalin Ilona AU - Seli, Bálint Attila AU - Kővári, Zsolt AU - Kriskovics, Levente AU - Vida, Krisztián TI - Characteristics of flares on giant stars JF - ASTRONOMY & ASTROPHYSICS J2 - ASTRON ASTROPHYS VL - 668 PY - 2022 SN - 0004-6361 DO - 10.1051/0004-6361/202243789 UR - https://m2.mtmt.hu/api/publication/33538419 ID - 33538419 N1 - Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Konkoly Thege Miklós út 15-17, Budapest, 1121, Hungary Csfk, Mta Centre of Excellence, Budapest, Konkoly Thege Miklós út 15-17, Budapest, 1121, Hungary Eötvös University, Department of Astronomy, Pf. 32, Budapest, 1518, Hungary Cited By :1 Export Date: 13 October 2023 CODEN: AAEJA AB - Context. Although late-type dwarfs and giant stars are substantially different, their flares are thought to originate in similar physical processes and differ only by a scale factor in the energy levels. We study the validity of this approach. LA - English DB - MTMT ER - TY - JOUR AU - Park, Sunkyung AU - Kóspál, Ágnes AU - Ábrahám, Péter AU - Fernando, Cruz-Saenz de Miera AU - Fiorellino, Elenonora AU - Siwak, Michal AU - Nagy, Zsófia AU - Giannini, Teresa AU - Carini, Roberta AU - Szabó, Zsófia Marianna AU - Lee, Jeong-Eun AU - Lee, Jae-Joon AU - Vitali, Fabrizio AU - Kun, Mária AU - Cseh, Borbála AU - Krezinger, Máté AU - Kriskovics, Levente AU - Ordasi, András AU - Pál, András AU - Szakáts, Róbert AU - Vida, Krisztián AU - Vinkó, József TI - Photometric and Spectroscopic Study of the EXor-like Eruptive Young Star Gaia19fct JF - ASTROPHYSICAL JOURNAL J2 - ASTROPHYS J VL - 941 PY - 2022 IS - 2 SN - 1538-4357 DO - 10.3847/1538-4357/aca01e UR - https://m2.mtmt.hu/api/publication/33537935 ID - 33537935 N1 - Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly-Thege Miklós út 15-17, Budapest, 1121, Hungary CSFK, MTA Centre of Excellence, Konkoly-Thege Miklós út 15-17, Budapest, 1121, Hungary Max Planck Institute for Astronomy, Königstuhl 17, Heidelberg, D-69117, Germany ELTE Eötvös Loránd University, Institute of Physics, Pázmány Péter sétány 1/A, Budapest, 1117, Hungary INAF-Osservatorio Astronomico di Capodimonte, via Moiariello 16, Napoli, I-80131, Italy INAF-Osservatorio Astronomico di Roma, Via Frascati 33, Monte Porzio Catone, I-00078, Italy Max-Planck-Institute für Radioastronomie, Auf dem Hügel 69, Bonn, D-53121, Germany Scottish Universities Physics Alliance (SUPA), School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, United Kingdom Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea Korea Astronomy and Space Science Institute, 776, Daedeok-daero, Yuseong-gu, Daejeon, 34055, South Korea MTA-ELTE Lendület “Momentum” Milky Way Research Group, Hungary Export Date: 15 February 2023 Correspondence Address: Park, S.; Konkoly Observatory, Konkoly-Thege Miklós út 15-17, Hungary; email: sunkyung.park@csfk.org AB - Gaia19fct is one of the Gaia-alerted eruptive young stars that has undergone several brightening events. We conducted monitoring observations using multifilter optical and near-infrared photometry, as well as near-infrared spectroscopy, to understand the physical properties of Gaia19fct and investigate whether it fits into the historically defined two classes. We present the analyses of light curves, color variations, spectral lines, and CO modeling. The light curves show at least five brightening events since 2015, and the multifilter color evolutions are mostly gray. The gray evolution indicates that bursts are triggered by mechanisms other than extinction. Our near-infrared spectra exhibit both absorption and emission lines and show time variability throughout our observations. We found lower rotational velocity and lower temperature from the near-infrared atomic absorption lines than from the optical lines, suggesting that Gaia19fct has a Keplerian rotating disk. The CO overtone features show a superposition of absorption and emission components, which is unlike other young stellar objects. We modeled the CO lines, and the result suggests that the emission and absorption components are formed in different regions. We found that although Gaia19fct exhibits characteristics of both types of eruptive young stars, FU Orionis–type objects and EX Lupi–type objects, it shows more similarity with EXors in general. LA - English DB - MTMT ER - TY - JOUR AU - Moór, Attila AU - Ábrahám, Péter AU - Szabó M., Gyula AU - Vida, Krisztián AU - Cataldi, Gianni AU - Derekas, Alíz AU - Henning, Thomas AU - Kinemuchi, Karen AU - Kóspál, Ágnes AU - Kovács, József AU - Pál, András AU - Sarkis, Paula AU - Seli, Bálint Attila AU - Szabó, Zsófia M. AU - Takáts, Katalin TI - Erratum: “A New Sample of Warm Extreme Debris Disks from the ALLWISE Catalog” (2021, ApJ, 910, 27) JF - ASTROPHYSICAL JOURNAL J2 - ASTROPHYS J VL - 940 PY - 2022 IS - 2 SN - 1538-4357 DO - 10.3847/1538-4357/aca280 UR - https://m2.mtmt.hu/api/publication/33535919 ID - 33535919 LA - English DB - MTMT ER -