Search Publications
Analysis of photometric and spectroscopic variability of red supergiant Betelgeuse
Jadlovský, Daniel; Krtička, Jiří; Paunzen, Ernst +1 more
Betelgeuse is a pulsating red supergiant whose brightness is semi periodically variable and in February 2020 reached a historical minimum, the Great Dimming. The aims of this study are to characterize Betelgeuse's variability based on available archival data and to study possible causes of light variability. Many spectra, from ultraviolet and opti…
Interstellar Polarization Survey. II. General Interstellar Medium
Magalhães, A. M.; Kawabata, Koji S.; Rodrigues, C. V. +4 more
Magnetic fields permeate the entire Galaxy and are essential to, for example, the regulation of several stages of the star formation process and cosmic-ray transportation. Unraveling their properties, such as intensity and topology, is an observational challenge that requires combining different and complementary techniques. The polarization of st…
Bursts from Space: MeerKAT - the first citizen science project dedicated to commensal radio transients
Heywood, Ian; Motta, Sara; Tremou, Evangelia +40 more
The newest generation of radio telescopes is able to survey large areas with high sensitivity and cadence, producing data volumes that require new methods to better understand the transient sky. Here, we describe the results from the first citizen science project dedicated to commensal radio transients, using data from the MeerKAT telescope with w…
JWST NIRCam Observations of SN 1987A: Spitzer Comparison and Spectral Decomposition
Temim, Tea; Boyer, Martha L.; Gall, Christa +24 more
JWST Near Infrared Camera (NIRCam) observations at 1.5-4.5 µm have provided broadband and narrowband imaging of the evolving remnant of SN 1987A with unparalleled sensitivity and spatial resolution. Comparing with previous marginally spatially resolved Spitzer Infrared Array Camera (IRAC) observations from 2004 to 2019 confirms that the emis…
Unfolding Drift Effects for Cosmic Rays over the Period of the Sun's Magnetic Field Reversal
Luo, Xi; Potgieter, M. S.; Aslam, O. P. M. +2 more
A well-established, comprehensive 3D numerical modulation model is applied to simulate galactic protons, electrons, and positrons from 2011 May to 2015 May, including the solar magnetic polarity reversal of Solar Cycle 24. The objective is to evaluate how simulations compare with corresponding Alpha Magnetic Spectrometer observations for 1.0-3.0 G…
Understanding the Lateral Drifting of an Erupting Filament with a Data-constrained Magnetohydrodynamic Simulation
Schmieder, B.; Poedts, S.; Li, C. +6 more
Solar filaments often exhibit rotation and deflection during eruptions, which would significantly affect the geoeffectiveness of the corresponding coronal mass ejections (CMEs). Therefore, understanding the mechanisms that lead to such rotation and lateral displacement of filaments is a great concern to space weather forecasting. In this paper, we…
Still alive and kicking: A significant outburst in changing-look AGN Mrk 1018
Granzer, T.; Gaspari, M.; Combes, F. +13 more
Context. Changing-look active galactic nuclei (AGN) have been observed to change their optical spectral type. Mrk 1018 is particularly unique: first classified as a type 1.9 Seyfert galaxy, it transitioned to being a type 1 Seyfert galaxy a few years later before returning to its initial classification as a type 1.9 Seyfert galaxy after ∼30 years.…
A high fidelity Milky Way simulation with Kraken, Gaia-Enceladus, and Sequoia analogues: clues to their accretion histories
Grand, Robert J. J.; Kawata, Daisuke; García-Bethencourt, Guacimara +1 more
Within a simulated Milky Way-like galaxy, we identify and analyse analogues of the Gaia-Enceladus (GE), Kraken, and Sequoia mergers that each matches remarkably well observational results, including in velocity and chemical abundance space, and their distributions in the jz-Energy plane. The Kraken analogue is the earliest merger and ha…
The Gaia alerted fading of the FUor-type star Gaia21elv
Lee, Jeong-Eun; Gromadzki, Mariusz; Ábrahám, Péter +26 more
FU Orionis objects (FUors) are eruptive young stars, which exhibit outbursts that last from decades to a century. Due to the duration of their outbursts, and to the fact that only about two dozens of such sources are known, information on the end of their outbursts is limited. Here we analyse follow-up photometry and spectroscopy of Gaia21elv, a y…
Global Structure of Magnetotail Reconnection Revealed by Mining Space Magnetometer Data
Sitnov, M. I.; Genestreti, K. J.; Tsyganenko, N. A. +5 more
Reconnection in the magnetotail occurs along so-called X-lines, where magnetic field lines tear and detach from plasma on microscopic spatial scales (comparable to particle gyroradii). In 2017-2020, the Magnetospheric MultiScale (MMS) mission detected X-lines in the magnetotail enabling their investigation on local scales. However, the global stru…