Article
Geosciences, Multidisciplinary
M. N. Chowdhury, T. S. Stallard, K. H. Baines, G. Provan, H. Melin, G. J. Hunt, L. Moore, J. O'Donoghue, E. M. Thomas, R. Wang, S. Miller, S. V. Badman
Summary: The Cassini spacecraft discovered that Saturn's magnetic field oscillates at a different rate than the planetary rotation. It is believed that this variation is caused by a polar twin-cell neutral weather system. Using spectral observations from the Keck Observatory in 2017, researchers derived ion velocity maps and found wind systems in Saturn's ionosphere that align with predicted neutral twin-vortex flow patterns. This study reveals the impact of neutral winds on Saturn's rotational period and introduces a previously unseen process within planetary atmospheres.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Editorial Material
Multidisciplinary Sciences
Marco Micheli
Summary: A simple and physically realistic model is proposed to reconcile the seemingly contradictory observations of the first known interstellar object, providing an understanding of its peculiarities.
Article
Astronomy & Astrophysics
Yashvi Sharma, Jesper Sollerman, Christoffer Fremling, Shrinivas R. Kulkarni, Kishalay De Kishalay, Ido Irani, Steve Schulze, Nora Linn Strotjohann, Avishay Gal-Yam, Kate Maguire, Daniel A. Perley, Eric C. Bellm, Erik C. Kool, Thomas G. Brink, Rachel Bruch, Maxime Deckers, Richard Dekany, Alison Dugas, Alexei V. Filippenko, Samantha Goldwasser, Matthew J. Graham, Melissa L. Graham, Steven L. Groom, Matt Hankins, Jacob Jencson, Joel P. Johansson, Viraj Karambelkar, Mansi M. Kasliwal, Frank J. Masci, Michael S. Medford, James D. Neill, Guy Nir, Reed L. Riddle, Mickael Rigault, Tassilo Schweyer, Jacco H. Terwel, Lin Yan, Yi Yang, Yuhan Yao
Summary: Among SNe interacting with CSM, there is a rare subclass called SNe Ia-CSM, which exhibit both IIn-like narrow hydrogen emission lines and the diluted spectrum of Type Ia SNe. By using the Zwicky Transient Facility (ZTF), we have discovered 12 more SNe Ia-CSM through the Bright Transient Survey (BTS). These SNe have slowly evolving light curves, weak Hα lines, and show signs of newly formed dust. The rate estimate for SNe Ia-CSM is 29+(27)(21) Gpc(-3) yr(-1), which corresponds to 0.02%-0.2% of the total SN Ia rate.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Ralph Neuhaeuser, Dagmar L. Neuhaeuser
Summary: The critical discussion of recent articles by S. Hoffmann and N. Vogt on historical novae and supernovae reveals issues with data inconsistency, calculation errors, and skepticism towards suggested historical nova identifications. Furthermore, their catalog of 24 promising nova events mostly consists of comets and lacks evidence of duration and accurate positioning for many candidates.
ASTRONOMISCHE NACHRICHTEN
(2021)
Article
Astronomy & Astrophysics
P. Stephenson, M. Galand, P. D. Feldman, A. Beth, M. Rubin, D. Bockelee-Morvan, N. Biver, Y. -C. Cheng, J. Parker, J. Burch, F. L. Johansson, A. Eriksson
Summary: The study aims to determine if dissociative excitation of cometary neutrals by electron impact is the main source of far-ultraviolet emissions at comet 67P/Churyumov-Gerasimenko. Multiple datasets from the Rosetta mission were combined for a multi-instrument analysis to model FUV emissions and compare to observations, showing that electron impact is the dominant source away from perihelion. The correlation between suprathermal electron flux variations and observed FUV line brightnesses suggests electrons are accelerated on large scales, originating from the solar wind, indicating the auroral nature of the FUV emissions.
ASTRONOMY & ASTROPHYSICS
(2021)
Review
Astronomy & Astrophysics
Dennis Bodewits, Zexi Xing, Mohammad Saki, Jeffrey P. P. Morgenthaler
Summary: The Neil-Gehrels Swift Observatory has significantly contributed to our understanding of small bodies in our solar system. Its rapid response and tracking capabilities have enabled important studies on the water sources in comets, changes in the rotation period of comets, and the properties of asteroids over time through near-UV spectroscopic observations.
Article
Astronomy & Astrophysics
Marc Williamson, Wolfgang Kerzendorf, Maryam Modjaz
Summary: This study investigates the potential presence of hidden helium in the ejecta of SNe Ic, with experiments showing that even a small outer He shell can produce strong spectral features. The comparison of tardis and Monte Carlo based radiation transfer codes for SN 1994I models demonstrates consistent synthetic spectra. The study suggests that NIR spectral follow-up of SNe Ic will be crucial for addressing the hidden helium question in a statistical sample of SNe Ic.
ASTROPHYSICAL JOURNAL
(2021)
Editorial Material
Multidisciplinary Sciences
Coralie D. Adam
Summary: A strategy to prevent asteroids from hitting Earth has successfully completed its initial test, confirming predictions about the impact response of asteroids and providing valuable insights.
Article
Astronomy & Astrophysics
Ralph Neuhaeuser, Dagmar L. Neuhaeuser, Jesse Chapman
Summary: The article discusses the study of galactic novae and supernovae through historical observations, presenting potential counterparts based on a list of historically reported transients from the Classical Chinese text corpus. However, the candidate selection and positional search areas lack justification, with errors in dates and misunderstandings affecting the research results.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Lindsay DeMarchi, R. Margutti, J. Dittman, A. Brunthaler, D. Milisavljevic, Michael F. Bietenholz, C. Stauffer, D. Brethauer, D. Coppejans, K. Auchettl, K. D. Alexander, C. D. Kilpatrick, Joe S. Bright, L. Z. Kelley, Michael C. Stroh, W. Jacobson-Galan
Summary: In this study, extensive multifrequency observations of supernova SN 2004C were conducted using Karl G. Jansky Very Large Array (VLA) and Very Long Baseline Array (VLBA). The temporal evolution of the radio spectral energy distribution was interpreted in the context of synchrotron self-absorbed emission from the explosion's forward shock. The observations and modeling revealed the characteristics of the blastwave and the density profile of the circumstellar medium (CSM).
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Wenxiong Li, Xiaofeng Wang, Mattia Bulla, Yen-Chen Pan, Lifan Wang, Jun Mo, Jujia Zhang, Chengyuan Wu, Jicheng Zhang, Tianmeng Zhang, Danfeng Xiang, Han Lin, Hanna Sai, Xinghan Zhang, Zhihao Chen, Shengyu Yan
Summary: The study reveals that the B - V colors, spectral features, and velocity variations of Type Ia supernovae are related to their birth environments and explosion mechanisms. High-velocity (HV) and normal-velocity (NV) supernovae may have similar progenitor metallicities, but different explosion mechanisms.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Yuan Qi Ni, Dae-Sik Moon, Maria R. Drout, Abigail Polin, David J. Sand, Santiago Gonzalez-Gaitan, Sang Chul Kim, Youngdae Lee, Hong Soo Park, D. Andrew Howell, Peter E. Nugent, Anthony L. Piro, Peter J. Brown, Lluis Galbany, Jamison Burke, Daichi Hiramatsu, Griffin Hosseinzadeh, Stefano Valenti, Niloufar Afsariardchi, Jennifer E. Andrews, John Antoniadis, Rachael L. Beaton, K. Azalee Bostroem, Raymond G. Carlberg, S. Bradley Cenko, Sang-Mok Cha, Yize Dong, Avishay Gal-Yam, Joshua Haislip, Thomas W. -S. Holoien, Sean D. Johnson, Vladimir Kouprianov, Yongseok Lee, Christopher D. Matzner, Nidia Morrell, Curtis McCully, Giuliano Pignata, Daniel E. Reichart, Jeffrey Rich, Stuart D. Ryder, Nathan Smith, Samuel Wyatt, Sheng Yang
Summary: SN 2018aoz is a Type Ia SN with unique light curves, and the nature and origin of the SN are constrained by the distribution of iron-peak elements and spectroscopic features. The possible origin and explosion mechanisms are related to the interaction between the binary companion and circumstellar material.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Sajad Abbar, Francesco Capozzi
Summary: Neutrinos in dense neutrino media can undergo fast flavor conversions caused by backward scattering off nuclei at relatively large distances. However, these instabilities are unlikely to cause significant flavor conversions if the population of neutrinos in the backward direction is not large enough.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
R. B. Firestone
Summary: The study compared accurately measured ages of 89 large impact craters and layers with boundary dates on the geological time-scale, showing a high correlation and non-randomness. It was found that no craters are in the oceans or ice, indicating more impact events than currently known. Multiple impacts cluster near boundary dates, with impact rates dramatically increasing over the past 125 million years, potentially impacting future global climate.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hongrui Wang, Huiduan Li
Summary: Based on historical records and new results from radiocarbon annual dataset, it is found that the solar minimum of 1618 was actually in 1620. The rediscovered naked-eye sunspot observations confirmed the active sunspot activity in 1618.
