Search Publications
Tracing the Propagation of Shocks in the Equatorial Ring of SN 1987A over Decades with the Hubble Space Telescope
Fransson, Claes; Larsson, Josefin; Tegkelidis, Christos
The nearby SN 1987A offers a unique opportunity to investigate the complex shock interaction between the ejecta and circumstellar medium. We track the evolution of the optical hot spots within the equatorial ring (ER) by analyzing 33 Hubble Space Telescope imaging observations between 1994 and 2022. By fitting the ER with an elliptical model, we d…
X-Ray Emission of Nearby Low-mass and Sunlike Stars with Directly Imageable Habitable Zones
Peacock, Sarah; Kane, Stephen R.; Schwieterman, Edward W. +5 more
Stellar X-ray and UV radiation can significantly affect the survival, composition, and long-term evolution of the atmospheres of planets in or near their host star's habitable zone (HZ). Especially interesting are planetary systems in the solar neighborhood that may host temperate and potentially habitable surface conditions, which may be analyzed…
Classifying the clouds of Venus using unsupervised machine learning
Molaverdikhani, K.; Grassi, T.; Ercolano, B. +2 more
Because Venus is completely shrouded by clouds, they play an important role in the planet's atmospheric dynamics. Studying the various morphological features observed on satellite imagery of the Venusian clouds is crucial to understanding not only the dynamic atmospheric processes, but also interactions between the planet's surface structures and …
A Diamond Ring in X-Ray: Investigating the Diffuse Emission of Supernova Remnant G28.8+1.5
Zhang, Kaiyue
Supernova remnants are products of supernova explosions, which are usually observed in the X-ray band. However, the diffuse emission from the galactic supernova remnant G28.8+1.5 has been overlooked following initial searches for pulsars and pulsar wind nebulae. This paper presents background-subtracted imaging and spatial-resolved spectral analys…
Millisecond pulsars phenomenology under the light of graph theory
de Martino, D.; Torres, D. F.; Papitto, A. +4 more
We compute and apply the minimum spanning tree (MST) of the binary millisecond pulsar population, and discuss aspects of the known phenomenology of these systems in this context. We find that the MST effectively separates different classes of spider pulsars – eclipsing radio pulsars in tight binary systems with a companion of either ~0.1–0.8 M
Comparison of Direct Magnetic Field Measurements in a Sunspot by Ten Spectral Lines of Fe I, Fe II, Ti I, and Ti II
Lozitsky, V. G.; Lozitska, N. I.; Yakovkin, I. I. +1 more
Direct magnetic field measurements in sunspots by many spectral lines are important for elucidating the true magnitude and structure of the magnetic field at different levels of the solar atmosphere. Currently, magnetographic measurements are the most widespread, but such measurements mainly represent the longitudinal component of the magnetic fie…
Compact ellipticals in the Antlia cluster of galaxies
Richtler, Tom; Caso, Juan Pablo; Bassino, Lilia P. +3 more
Context. Compact ellipticals (cEs) are rare objects in the local Universe, but relevant for the evolution of galaxies. Their origin is not completely understood, with evidence equally suggesting that they are relics of early epochs, and remnants of tidal disruptions. Aims. This article aims to characterise two cEs, members of the nearby Antlia clu…
Ultra-Low Frequency Waves of Foreshock Origin Upstream and Inside of the Magnetospheres of Earth, Mercury, and Saturn Related to Solar Wind–Magnetosphere Coupling
Juhász, Antal; Bebesi, Zsofia; Dwivedi, Navin Kumar +2 more
This review examines ultra-low frequency (ULF) waves across different planetary environments, focusing on Earth, Mercury, and Saturn. Data from spacecraft missions (CHAMP, Swarm, and Oersted for Earth; MESSENGER for Mercury; and Cassini for Saturn) provide insights into ULF wave dynamics. At Earth, compressional ULF waves, particularly Pc3 waves, …
Witt's Hyperbola Is Both Predicted and Observed to Pass Close to the Lensing Galaxies in Quadruple Quasars
Schechter, Paul L.; Luhtaru, Richard
When a rectangular hyperbola is constructed from the image positions of a quadruply lensed quasar, as proposed by Witt, it passes very close to the lensing galaxy. The median measured perpendicular offset between the observed light center of the lens and Witt's hyperbola is 0.″013 for a sample for 39 systems lensed by a relatively isolated galaxy.…
ASASSN-21js: A multi-year transit of a ringed disc
van Boekel, R.; Kenworthy, M. A.; Pramono, T. H.
Aims: The early-type star ASASSN-21js started to fade in 2021, as was detected by the All Sky Automated Survey for Supernovae, undergoing a multi-year eclipse that is still underway. We interpret this event as being due to a structured disc of material transiting in front of the star. The disc is in orbit around a substellar object with the m…