Article
Astronomy & Astrophysics
Zhen Guo, P. W. Lucas, L. C. Smith, C. Clarke, C. Contreras Pena, A. Bayo, C. Briceno, J. Elias, R. G. Kurtev, J. Borissova, J. Alonso-Garcia, D. Minniti, M. Catelan, F. Nikzat, C. Morris, N. Miller
Summary: This article presents the results of near-infrared photometry obtained by the VVV survey over the past decade, focusing on the Galactic bulge and the southern disc plane. A modified Lomb-Scargie method was used to search for large-amplitude mid to long-term periodic variables, leading to the discovery of 1520 periodic sources, including 59 candidate periodic outbursting young stellar objects. The study also found different types of periodic outbursts and suggested that these cycles may be caused by dynamical perturbations from stellar or planetary companions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Dodin, E. A. Suslina
Summary: The study reveals that dust clouds obscuring young stars do so in an uneven manner, with complex structure and significant extinction gradients, resulting in variable shaping of stellar absorption lines. This complexity leads to a noticeable Rossiter-McLaughlin effect in addition to high extinction gradients within the clouds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
L. Hambalek, V Krushevska, T. Pribulla, M. Vanko, J. Budaj, M. Fiorucci, Z. Garai, E. Guenther, R. Komzik, E. Kundra, U. Munari, B. Smalley
Summary: This study presents the results of long-term spectroscopic monitoring of 21 T-Tauri stars in the Taurus-Auriga star-forming region. The analysis reveals no close binary companion and provides information about atmospheric parameters, age, mass, and radius of the stars. The findings indicate that these stars are young with ages younger than 50 Myr, average age of 5±3 Myr, mass between 0.75 and 2.10 M-circle dot, and minimum radii in the range 0.60-3.17 R-circle dot.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. G. Shulman, V. P. Grinin
Summary: We simulate the polarized radiative transfer during the minima of UX Ori type stars and investigate the influence of perturbation extensions on eclipse depth and linear polarization parameters. Our results show that large-scale azimuthally extended perturbations can cause deeper eclipses with greater linear polarization. The extension of perturbations and puffing-up of the disk also strongly affect the polarization and color index of the star during the eclipse.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Asen Mutafov, Evgeni Semkov, Stoyanka Peneva, Sunay Ibryamov
Summary: This paper reports the results of optical photometric observations of the pre-main sequence star V1180 Cas. The star shows large amplitude variability, which is interpreted as a combination of accretion-induced and extinction-driven effects. By comparing the photometric data with observations of other low-mass pre-main sequence objects, a better understanding of the properties of these celestial bodies can be obtained.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
M. Villenave, F. Menard, W. R. F. Dent, M. Benisty, G. van der Plas, J. P. Williams, M. Ansdell, A. Ribas, C. Caceres, H. Canovas, L. Cieza, A. Hales, I. Kamp, C. Pinte, D. A. Principe, M. R. Schreiber
Summary: The study compares the dust masses of protoplanetary disks in the Chamaeleon II star-forming region with other regions aged between 1 and 10 million years. Results show that most disk dust masses in Cha II are lower than 10 Earth masses and there are no significant differences in dust mass distributions compared to other regions.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
C. Koen
Summary: The study aims to investigate the photometric variability in the candidate host star CVSO 30 and determine if it can be explained by starspots. By separating the TESS light curve into two independent non-sinusoidal periodic components and applying starspot modelling technique, the two model light curves combined accurately reproduce the TESS observations, eliminating the need for invoking planetary transits to describe the variability.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
R. Arun, Blesson Mathew, P. Manoj, G. Maheswar, B. Shridharan, Sreeja S. Kartha, Mayank Narang
Summary: This study presents a large mid-infrared spectral catalogue of Herbig Ae/Be stars, revealing the detection of infrared vibrational modes of C-60 bands in nine sources and the presence of C-60 emission features in the circumstellar disc or nearby diffused emission region of three stars. The detection fraction of C-60 is 7% in the total sample and 30% for stars associated with nebulosity. These findings contribute to understanding the excitation and formation pathway of C-60.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. Koen
Summary: The photometry of 10 young stars from the 'Transiting Exoplanet Survey Satellite' with complex periodic light curves was considered. It was found that almost all light curves can be accurately modeled by re-evaluating the ratios of spot to photospheric fluxes, although the caveat that these models are not unique applies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Zsofia Nagy, Sunkyung Park, Peter Abraham, Agnes Kospal, Fernando Cruz-Saenz de Miera, Maria Kun, Michal Siwak, Zsofia Marianna Szabo, Mate Szilagyi, Eleonora Fiorellino, Teresa Giannini, Jae-Joon Lee, Jeong-Eun Lee, Gabor Marton, Laszlo Szabados, Fabrizio Vitali, Jan Andrzejewski, Mariusz Gromadzki, Simon Hodgkin, Maja Jablonska, Rene A. Mendez, Jaroslav Merc, Olga Michniewicz, Przemyslaw J. Mikolajczyk, Uliana Pylypenko, Milena Ratajczak, Lukasz Wyrzykowski, Michal Zejmo, Pawel Zielinski
Summary: In this study, the researchers analyzed the spectroscopy of Gaia21elv, a young stellar object, and confirmed it as a classical FUor, the third such object discovered among the Gaia science alerts. The spectroscopy showed typical FUor signatures, such as a triangular shaped H-band continuum, absorption-line dominated spectrum, and P Cygni profiles. Additionally, [O I], [FeII], and [S II] were detected, suggesting the presence of a jet or disc wind.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Zsofia Nagy, Elza Szegedi-Elek, Peter Abraham, Agnes Kospal, Attila Bodi, Jerome Bouvier, Maria Kun, Attila Moor, Borbala Cseh, Aniko Farkas-Takacs, Otto Hanyecz, Simon Hodgkin, Bernadett Ignacz, Csaba Kiss, Reka Konyves-Toth, Levente Kriskovics, Gabor Marton, Laszlo Meszaros, Andras Ordasi, Andras Pal, Paula Sarkis, Krisztian Sarneczky, Adam Sodor, Laszlo Szabados, Zsofia Marianna Szabo, Robert Szakats, Dora Tarczay-Nehez, Krisztian Vida, Gabriella Zsidi
Summary: The study found that V555 Ori, a T Tauri star, experienced brightness variations mainly due to extinction effects, showing long-term and short-term brightness oscillations. Its low accretion rate is not enough to explain the optical flux changes, similar to AA Tau. The periodic behavior of V555 Ori was detectable in both high and low brightness states.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Zsofia Nagy, Peter Abraham, Agnes Kospal, Sunkyung Park, Michal Siwak, Fernando Cruz-Saenz de Miera, Eleonora Fiorellino, David Garcia-Alvarez, Zsofia Marianna Szabo, Simone Antoniucci, Teresa Giannini, Alessio Giunta, Levente Kriskovics, Maria Kun, Gabor Marton, Attila Moor, Brunella Nisini, Andras Pal, Laszlo Szabados, Pawel Zielinski, Lukasz Wyrzykowski
Summary: This study investigates two young stars that experienced brightness increases on a year-long time scale. The analysis of light curves, photometry, and spectra reveals that these stars have similar accretion parameters to classical T Tauri stars, but their brightness amplitudes and time scales place them in a region of the parameter space rarely occupied by young stars. This suggests the existence of a new class of young stars that produce outbursts similar to young eruptive stars, but with smaller amplitudes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Filocomo, J. F. Albacete-Colombo, E. Mestre, L. J. Pellizza, J. A. Combi
Summary: In this study, we propose that NGC 2071 star-forming region could be a counterpart to some unidentified gamma-ray sources. By analyzing the data from the Fermi satellite, we have found that the gamma-ray source in NGC 2071 was detectable during the first 2 years of observation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Takahiro Ueda, Luca Ricci, Mario Flock, Zachary Castro
Summary: This study investigates the capabilities of ALMA and ngVLA in observing the dust concentration at the inner edge of the dead zone in protoplanetary disks. The findings show that ngVLA can detect the dust concentration with its unprecedented angular resolution and sensitivity, while ALMA cannot resolve its spatial distribution.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
S. Melnikov, P. A. Boley, N. S. Nikonova, A. Caratti O. Garatti, R. Garcia Lopez, B. Stecklum, J. Eisloeffel, G. Weigelt
Summary: The study examines the Th 28 jet and finds that the brightness of its jet lobes is asymmetric, possibly due to asymmetry in the physical parameters of the jet plasma in opposite jet lobes. High-resolution observations using the SINFONI instrument reveal differences in the jet parameters and structures, and comparisons with other asymmetric YSO jets help determine the physical origin of these asymmetries.
ASTRONOMY & ASTROPHYSICS
(2023)