Search Publications
3D projection analysis: Characterizing the morphological stability of nearby open clusters
Hu, Qingshun; Luo, Yangping; Li, Yuting +1 more
Context. The study of open cluster morphology is pivotal for exploring their formation and evolutionary processes. Aims. We manage to assess the morphological stability of 105 nearby open clusters within tidal radii on the X-Y, X-Z, and Y-Z planes of the heliocentric Cartesian coordinate system, utilizing member catalogs from the literature. Meanw…
Comparison of methods used to derive the Galactic star formation history from white dwarf samples
Tremblay, Pier-Emmanuel; O'Brien, Mairi W.; Bédard, Antoine +4 more
We compare three methods of deriving the local Galactic star formation history, using as a benchmark the Gaia-defined 40 pc white dwarf sample, currently the largest volume complete sample of stellar remnants with medium-resolution spectroscopy. We create a population synthesis model to (1) reproduce the observed white dwarf luminosity function, (…
Detection of Eclipses in the Cataclysmic Variable LAMOST J035913.61 + 405035.0
Kozhevnikov, V. P.
I conducted photometric observations of the cataclysmic variable LAMOST J035913.61 + 405035.0 and detected eclipses. During these observations, I recorded 14 eclipses over two groups of nights separated by 13 months. I accurately determined the orbital period of the system to be $$ {P}_{\mathrm{orb}}=0.228\kern0.1em 343\kern0.1em 85\pm 0.000\kern0…
Superstrong Magnetic Fields in Sunspot Bipolar Light Bridges
Solanki, S. K.; Korpi-Lagg, A.; Castellanos Durán, J. S. +2 more
Recent solar observations of bipolar light bridges (BLBs) in sunspots have, in a few individual cases, revealed magnetic fields up to 8.2 kG, which is at least twice as strong as typical values measured in sunspot umbrae. However, the small number of such observations hinted that such strong fields in these bright photospheric features that separa…
Primordial Origin of Methane on Eris and Makemake Supported by D/H Ratios
Mousis, Olivier; Werlen, Aaron; Benest Couzinou, Tom +1 more
Deuterium, a heavy isotope of hydrogen, is a key tracer of the formation of the solar system. Recent James Webb Space Telescope observations have expanded the data set of deuterium-to-hydrogen (D/H) ratios in methane on the KBOs Eris and Makemake, providing new insights into their origins. This study examines the elevated D/H ratios in methane on …
Old Dogs, New Tricks: Re-examining Photographic Spectra of Plaskett's Star
Davidge, T. J.
Photographic spectra of Plaskett's Star (HR 2420, HD 47129, V640 Monocerotis) that were recorded at the Dominion Astrophysical Observatory have been digitized with a flatbed scanner. Many of the spectra were recorded during campaigns in 1922 and 1937, and cover wavelengths between 0.39 and 0.50 µm. Spectra of poor quality are identified. Mea…
Boulder Migration in the Khonsu Region of Comet 67P/Churyumov–Gerasimenko
Shi, Xian; El-Maarry, Mohamed Ramy; Tang, Xiang
The European Space Agency's Rosetta mission is the only space mission that has performed long-term monitoring of a comet at close distances. For over two years, Rosetta rendezvoused with comet 67P/Churyumov–Gerasimenko, which revealed diverse evolutionary processes of the cometary nucleus. One of the most striking events is the migration of a ∼30 …
Dynamic Photometric Variability in Three Young Brown Dwarfs in Taurus: Detection of Optical Flares with TESS Data
Joshi, Santosh; Dutta, Somnath; Mondal, Soumen +4 more
We present I-band time-series photometric variability studies of three known nearby (∼140 pc) and young (∼1 Myr) brown dwarfs (BD) in the Taurus star-forming region in the Perseus molecular cloud. From 10 nights of observations over a time span of 10 yr, with a typical run of 3–6 hr each night, we estimated that the BDs show unstable short-scale p…
Relationships between lobate debris aprons and lineated valley fill on Mars: Evidence for an extensive Amazonian valley glacial landsystem in Mamers Valles
Head, James W.; Hiesinger, Harald; Jawin, Erica R. +3 more
We examine the characteristics and relationships of Lineated Valley Fill (LVF) and Lobate Debris Aprons (LDA) in Mamers Valles on Mars, a ∼950 km-long fretted valley at the dichotomy boundary. The relationships and distinctions between these glacial landforms are established by detailed analysis of LDA/LVF morphology, topography, and related featu…
Statistics of the Interplanetary Magnetic Field from 0.1 to 30 au. I. Distribution Character
Zong, Qiugang; He, Jiansen; Yang, Liu +7 more
This study investigates the directional and intensity distributions of the interplanetary magnetic field (IMF) across a heliocentric distance range of approximately 0.1–30 au. Measurements from multiple spacecraft reveal that these distributions align closely with the Parker spiral configuration in general. Nevertheless, the deviation from the mod…