Search Publications
Magnetosheath Plasma Flow and Its Response to IMF and Geodipole Tilt as Obtained From the Data-Based Modeling
Semenov, V. S.; Erkaev, N. V.; Tsyganenko, N. A. +1 more
Large-scale patterns of the steady-state magnetosheath plasma flow and their dependence on the interplanetary magnetic field (IMF) have been reconstructed for the first time on the basis of large multi-year multi-mission pool of spacecraft observations, concurrent interplanetary data, and an empirical high-resolution model. The flow model architec…
SPECtrophotometer for TRansmission Spectroscopy of Exoplanets (SPECTR)
Lee, Byeong-Cheol; Park, Myeong-Gu; Choi, Yeon-Ho +9 more
The SPECtrophotometer for TRansmission spectroscopy of exoplanets (SPECTR) is a new low-resolution optical (3800–6850 Å) spectrophotometer installed at the Bohyunsan Optical Astronomy Observatory 1.8 m telescope. SPECTR is designed for observing the transmission spectra of transiting exoplanets. Unique features of SPECTR are its long slit length o…
Searching for stellar population in the molecular cloud GRSMC 045.49+00.04
Elia, Davide; Azatyan, Naira; Nikoghosyan, Elena +5 more
Understanding the characteristics of young stellar populations is essential for deriving insights into star formation processes within parent molecular clouds and the influence of massive stars on these processes. This study primarily aims to investigate the young stellar objects (YSOs) within the molecular cloud G 045.49+00.04, including three ul…
Discovering Subsolar Metallicity Brown Dwarf Candidates in the Small Magellanic Cloud
Pacifici, Camilla; Manjavacas, Elena; Sabbi, Elena +3 more
We present the discovery of the first rich population of brown dwarf candidates (cBD) at subsolar metallicity, observed by JWST outside the Milky Way (MW) in the young SMC star cluster NGC 602. Located in the Small Magellanic Cloud (SMC) "wing," in a very low-density environment (1.3 cm‑3) and at subsolar metallicity, NGC 602 is very yo…
First determination of the system parameters in five contact binaries
Dębski, B.; Kulczycka, L.; Skrobacz, W. +2 more
We present solutions of the BVRI-light curve numerical modeling for five low-mass ratio totally eclipsing contact binary stars. One object required the introduction of a cool star spot to the best-fitting model. Only one object returned a solution with a hotter secondary component. None of the objects required the introduction of a third component.
The true age of multi-planet host star HD 110067: Or: Don't be fooled by K0V-type stars
Fridlund, Malcolm; Jack, Dennis; Schröder, Klaus-Peter +3 more
HD 110067 is a near (d = 32.22 pc, V = 8.43 mag) K0V star in Coma Ber that was recently discovered to host a six-planet system in stable resonances. The star has a very old age of 8+/‑4 Gyr. However, by the nature of the respective evolution tracks (i.e. with masses of 0.78...0.85 M⊙), which run parallel to the zero-age main sequence fo…
Decay Timescales of Chromospheric Condensations in Solar Flare Footpoints
Kowalski, Adam F.; Butler, Elizabeth C.
Chromospheric condensations (CCs) are a prominent feature of flare footpoint heating in the solar flare standard model, yet their timescales and velocities are not well understood. Fisher derived several important analytical relationships, which have rarely been examined with modern spectral observations. The Interface Region Imaging Spectrograph …
Revised ephemeris and orbital period derivative of the supersoft X-ray source CAL 87 based on 34 yr of observations
Saito, R. K.; Oliveira, A. S.; D'Amico, F. +4 more
In this study, we present an analysis of over 34 yr of observational data from CAL 87, an eclipsing supersoft X-ray source. The primary aim of our study, which combines previously analysed measurements as well as unexplored publicly available data sets, is to examine the orbital period evolution of CAL 87. After meticulously and consistently deter…
Multispacecraft Energetic Particle Enhancements Associated with a Single Corotating Interaction Region
Desai, M. I.; Dayeh, M. A.; Elliott, H. A. +3 more
The radial evolution of particles accelerated at corotating interaction regions (CIRs) is not fully understood, particularly the distance range over which this particle acceleration occurs and how the energy spectra are modulated by transport through the inner heliosphere. Here, we present observations of energetic proton enhancements associated w…
A study of Be stars in the time domain - I. Spectral data and polarimetry
Steele, Iain A.; Jermak, Helen E.; Castañón Esteban, Adrian
We present the first part of a spectroscopic and polarimetric study on a sample of 58 Be stars that have been measured since 1998. The aim of the study is to understand the time-scales of disc variability, formation, and dissipation as a function of the properties (mass, luminosity, and rotational velocity) of the underlying B star. In this paper,…