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TIC 308396022: δ Scuti-γ Doradus hybrid with large-amplitude radial fundamental mode and regular g-mode period spacing
DOI: 10.1051/0004-6361/202142198 Bibcode: 2021A&A...655A..63Y

Li, Gang; Bedding, Timothy R.; Murphy, Simon J. +3 more

We analyse the pulsating behaviour of TIC 308396022, based on observations by the TESS mission. The star is a high-amplitude δ Sct star that shows a very rich amplitude spectrum using the 3-yr light curve. Among these frequencies, the strongest peak of f1 = 13.20362567(12) d−1 is identified as the radial fundamental mode, and…

2021 Astronomy and Astrophysics
Gaia 13
Radio observations of massive stars in the Galactic centre: The Arches Cluster
DOI: 10.1051/0004-6361/202039172 Bibcode: 2021A&A...647A.110G

Herrero-Illana, R.; Alberdi, A.; Najarro, F. +8 more

We present high-angular-resolution radio observations of the Arches cluster in the Galactic centre, one of the most massive young clusters in the Milky Way. The data were acquired in two epochs and at 6 and 10 GHz with the Karl G. Jansky Very Large Array. The rms noise reached is three to four times better than during previous observations and we …

2021 Astronomy and Astrophysics
eHST 13
The GALAH Survey: using galactic archaeology to refine our knowledge of TESS target stars
DOI: 10.1093/mnras/stab1052 Bibcode: 2021MNRAS.504.4968C

Ting, Yuan-Sen; Morton, Timothy D.; Wittenmyer, Robert A. +29 more

An unprecedented number of exoplanets are being discovered by the Transiting Exoplanet Survey Satellite (TESS). Determining the orbital parameters of these exoplanets, and especially their mass and radius, will depend heavily upon the measured physical characteristics of their host stars. We have cross-matched spectroscopic, photometric, and astro…

2021 Monthly Notices of the Royal Astronomical Society
Gaia 13
ASASSN-18aan: An eclipsing SU UMa-type cataclysmic variable with a 3.6-hr orbital period and a late G-type secondary star
DOI: 10.1093/pasj/psab003 Bibcode: 2021PASJ...73.1209W

Thorstensen, John R.; Nogami, Daisaku; Sasada, Mahito +41 more

We report photometric and spectroscopic observations of the eclipsing SU UMa-type dwarf nova ASASSN-18aan. We observed the 2018 superoutburst with 2.3 mag brightening and found the orbital period (Porb) to be 0.149454(3) d, or 3.59 hr. This is longward of the period gap, establishing ASASSN-18aan as one of a small number of long-Po…

2021 Publications of the Astronomical Society of Japan
Gaia 13
Submillimeter imaging of the Galactic Center starburst Sgr B2. Warm molecular, atomic, and ionized gas far from massive star-forming cores
DOI: 10.1051/0004-6361/202040221 Bibcode: 2021A&A...649A..32S

Cernicharo, J.; Goicoechea, J. R.; Etxaluze, M. +2 more

Context. Star-forming galaxies emit bright molecular and atomic lines in the submillimeter and far-infrared (FIR) domains. However, it is not always clear which gas heating mechanisms dominate and which feedback processes drive their excitation.
Aims: The Sgr B2 complex is an excellent template to spatially resolve the main OB-type star-formi…

2021 Astronomy and Astrophysics
Herschel 13
Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration against Spectral Types and V - K Color
DOI: 10.3847/1538-4357/ac1687 Bibcode: 2021ApJ...922..163V

Ciardi, David R.; Clark, Catherine A.; van Belle, Gerard T. +8 more

We calculate directly determined values for effective temperature (T eff) and radius (R) for 191 giant stars based upon high-resolution angular size measurements from optical interferometry at the Palomar Testbed Interferometer. Narrow- to wideband photometry data for the giants are used to establish bolometric fluxes and luminosities t…

2021 The Astrophysical Journal
Gaia 13
Heavy-elements heritage of the falling sky
DOI: 10.1051/0004-6361/202038943 Bibcode: 2021A&A...648A.108R

de Laverny, Patrick; Recio-Blanco, Alejandra; Helmi, Amina +3 more

Context. A fundamental element of galaxy formation is the accretion of mass through mergers of satellites or gas. Recent dynamical analyses based on Gaia data have revealed major accretion events in the history of the Milky Way. Nevertheless, our understanding of the primordial Galaxy is hindered because the bona fide identification of the most me…

2021 Astronomy and Astrophysics
Gaia 13
Random Walk and Trapping of Interplanetary Magnetic Field Lines: Global Simulation, Magnetic Connectivity, and Implications for Solar Energetic Particles
DOI: 10.3847/1538-4357/abd7f0 Bibcode: 2021ApJ...908..174C

Matthaeus, William H.; Goldstein, Melvyn L.; Usmanov, Arcadi V. +4 more

The random walk of magnetic field lines is an important ingredient in understanding how the connectivity of the magnetic field affects the spatial transport and diffusion of charged particles. As solar energetic particles propagate away from near-solar sources, they interact with the fluctuating magnetic field, which modifies their distributions. …

2021 The Astrophysical Journal
Ulysses 13
A Comprehensive Analysis of NGC 2158 in the Gaia Era: Photometric Parameters, Apex, and Orbit
DOI: 10.3847/1538-3881/abd31d Bibcode: 2021AJ....161..101S

Bisht, D.; Yadav, R. K. S.; Vereshchagin, S. V. +7 more

We present an investigation of NGC 2158 using Gaia DR2 data. We identified 800 most likely cluster members with membership probability higher than 90%. The mean proper motions of this object are determined as (µx = -0.203 ± 0.003, µy = -1.99 ± 0.004) mas yr-1. The limiting radius, log(age), and distance…

2021 The Astronomical Journal
Gaia 13
Probing Current Sheet Instabilities from Flare Ribbon Dynamics
DOI: 10.3847/1538-4357/ac256f Bibcode: 2021ApJ...922..117F

Matthews, Sarah A.; French, Ryan J.; Jonathan Rae, I. +1 more

The presence of current sheet instabilities, such as the tearing mode instability, are needed to account for the observed rate of energy release in solar flares. Insights into these current sheet dynamics can be revealed by the behavior of flare ribbon substructure, as magnetic reconnection accelerates particles down newly reconnected field lines …

2021 The Astrophysical Journal
IRIS 13