Search Publications
SRG/ART-XC, Swift, NICER, and NuSTAR study of different states of the transient X-ray pulsar MAXI J0903-531
Wilms, Jörn; Doroshenko, Victor; Tsygankov, Sergey S. +6 more
The results of the broadband spectral and timing study of the recently discovered transient X-ray pulsar MAXI J0903-531 in a wide range of luminosities that differ by a factor of ~30 are reported. The observed X-ray spectrum in both states can be described as a classical pulsar-like spectrum consisting of a power law with a high-energy cutoff. We …
Tracking of magnetic helicity evolution in the inner heliosphere. A radial alignment study
Richter, I.; Narita, Y.; Hadid, L. Z. +5 more
Context. Magnetic helicity is one of the invariants in ideal magnetohydrodynamics, and its spectral evolution has a substantial amount of information to reveal the mechanism that are behind turbulence in space and astrophysical plasmas.
Aims: The goal of our study is to observationally characterize the magnetic helicity evolution in the inner…
New Short-Period δ Scuti Stars in OGLE-IV Fields toward the Galactic Bulge
Soszyński, I.; Udalski, A.; Szymański, M. K. +12 more
We report the classification of 24 puzzling short-period variable stars located in OGLE-IV Galactic bulge fields. The stars are low-amplitude (<0.05 mag) multi-periodic objects with dominant periods between 22 min and 54 min whose type could not have been unambiguously established based on photometry only. A low-resolution spectroscopic follow-…
Power Anisotropy, Dispersion Signature and Turbulence Diffusion Region in the 3D Wavenumber Domain of Space Plasma Turbulence
Verscharen, Daniel; He, Jiansen; Sahraoui, Fouad +4 more
We explore the multifaceted important features of turbulence (e.g., anisotropy, dispersion, and diffusion) in the three-dimensional (3D) wavenumber domain (k ∥, k ⊥,1, k ⊥,2), by employing the k-filtering technique to high-quality measurements of fields and particles from the Magnetospheric Multiscale Mission (MMS)…
Venus' Cloud-Tracked Winds Using Ground- and Space-Based Observations with TNG/NICS and VEx/VIRTIS
Machado, Pedro; Peralta, Javier; Silva, José E. +3 more
Characterizing the wind speeds of Venus and their variability at multiple vertical levels is essential for a better understanding of the atmospheric superrotation, constraining the role of large-scale planetary waves in the maintenance of this superrotation, and in studying how the wind field affects clouds' distribution. Here, we present cloud-tr…
WASP-35 and HAT-P-30/WASP-51: Reanalysis using TESS and Ground-based Transit Photometry
Wang, Xiaobin; Gu, Shenghong; Sun, Leilei +3 more
High-precision transit observations provide excellent opportunities for characterizing the physical properties of exoplanetary systems. These physical properties supply many pieces of information for unvealing the internal structure, external atmosphere, and dynamical history of the planets. We present revised properties of the transiting systems …
A Search for Analogs of KIC 8462852 (Boyajian's Star): A Second List of Candidates
Schmidt, Edward G.
In data from the Kepler mission, the normal F3V star KIC 8462852 (Boyajian's star) was observed to exhibit infrequent dips in brightness that have not been satisfactorily explained. A previous paper reported the first results of a search for other similar stars in a limited region of the sky around the Kepler field. This paper expands on that sear…
Is Fermi 1544-0649 a Misaligned Blazar? Discovering the Jet Structure with Very Long Baseline Interferometry
Zhang, Zhongli; Chen, Wen; Cheng, Xiaopeng +8 more
Fermi J1544-0649 is a transient GeV source first detected during its GeV flares in 2017. Multiwavelength observations during the flaring time demonstrate variability and spectral energy distributions that are typical of a blazar. Other than the flare time, Fermi J1544-0649 is quiet in the GeV band and has looked rather like a quiet galaxy (2MASX J…
Sunspot numbers and proton events in solar cycles 19 to 24
Bromage, B. J. I.; Birch, M. J.
In this study we compare the mean annual sunspot numbers for the six most recent solar cycles (19 to 24) with the number of solar energetic proton events occurring in those years. Though most of the individual cycles exhibit quite strong correlations, when they are combined into a generic solar cycle the result is very significant (ρ = 0.98). For …
CME-related Large Decreases in the Differential Phase Delay of Tianwen-1 DOR Signals
Liu, Kaijun; Guo, Li; He, Qingbao +2 more
Differential phase delay is calculated for the differential one-way range (DOR) signals transmitted by Tianwen-1, the first Chinese Mars spacecraft that entered into the Mars orbit on 2021 February 10. Large decreases in the differential phase delay are identified in the DOR signals received by ground stations on 2021 March 23 and June 18. The dec…