Search Publications
VY Scl-type cataclysmic variable SDSS J154453.60+255348.8: stellar and disc parameters
Wolf, M.; Zharikov, S.; Kára, J. +3 more
We present a new study of the eclipsing cataclysmic variable SDSS J154453.60+255348.8 to determine the object's nature and its system parameters together with the probe of the accretion flow structure in the system. Based on analyses of new simultaneous time-resolved photometric and spectroscopic observations of SDSS J154453.60+255348.8 and using …
TDCOSMO. XI. New lensing galaxy redshift and velocity dispersion measurements from Keck spectroscopy of eight lensed quasar systems
Treu, T.; Fassnacht, C. D.; Spiniello, C. +2 more
We have measured the redshifts and single-aperture velocity dispersions of eight lens galaxies using the data collected by the Echellette Spectrograph and Imager (ESI) and Low Resolution Imaging Spectrometer (LRIS) at W.M. Keck observatory on different observing nights spread over three years (2018-2020). These results, combined with other ancilla…
Heliocentric distance dependence of zodiacal light observed by Hayabusa2#
Tatsumi, Eri; Sugita, Seiji; Matsuura, Shuji +21 more
Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as
Hubble Detects the Start of a New Saturn Ring Spoke Season
Nicholson, Philip D.; Hedman, Matthew M.; Showalter, Mark R. +4 more
Saturn's ring spokes typically appear over an 8-year duration centered on equinox. Hubble Space Telescope observations in 2021 indicate the beginning of a new spoke season as Saturn approaches equinox in 2025. The spokes show increased contrast and longevity in 2022, persisting for up to 11 hours. The spokes are visible from UV to near-IR and are …
Modeling the Chromosphere and Transition Region of Planet-hosting Star GJ 436
Peacock, Sarah; Barman, Travis; Hatzes, Artie P. +12 more
Ahead of upcoming space missions intending to conduct observations of low-mass stars in the ultraviolet (UV) spectral region it becomes imperative to simultaneously conduct atmospheric modeling from the UV to the visible (VIS) and near-infrared (NIR). Investigations on extended spectral regions will help to improve the overall understanding of the…
Searching for signatures of H α spicule-like features in the solar transition region
Shetye, Juie; Doyle, J. Gerry; Vilangot Nhalil, Nived
New instruments and telescopes covering the optical and ultraviolet spectral regions have revealed a range of small-scale dynamic features, many which may be related. For example, the range of spicule-like features hints towards a spectrum of features and not just two types; however, direct observational evidence in terms of tracking spicules acro…
Spectroscopic study of Herbig Ae/Be stars in the Galactic anti-centre region from LAMOST DR5
Arun, R.; Mathew, Blesson; Kartha, Sreeja S. +3 more
We study a sample of 119 Herbig Ae/Be stars in the Galactic anti-centre direction using the spectroscopic data from large sky area multi-object fiber spectroscopic telescope survey program. Emission lines of hydrogen belonging to the Balmer and Paschen series, and metallic lines of species such as Fe II, O I, Ca II triplet are identified. A modera…
Testing the planetary hypothesis of NY Virginis: anticipated change in the eclipse timing trend within the next five years
Baştürk, Özgür; Esmer, Ekrem Murat; Selam, Selim Osman
Regarding the recent debate about the potential circumbinary exoplanets around NY Virginis (NY Vir), we analysed mid-eclipse timings of NY Vir using archival photometric data as well as our own observations and the ones from TESS. For this purpose, we first modelled the available eclipse light curves of the binary system to determine the masses of…
LBT-MODS spectroscopy of high-redshift candidates in the Chandra J1030 field. A newly discovered z ∼ 2.8 large-scale structure
Comastri, Andrea; Signorini, Matilde; Vito, Fabio +13 more
We present the results of a spectroscopic campaign with the Multi-Object Double Spectrograph (MODS) instrument mounted on the Large Binocular Telescope (LBT), aimed at obtaining a spectroscopic redshift for seven Chandra J1030 sources with a photometric redshift ≥2.7 and optical magnitude rAB = [24.5 − 26.5]. We obtained a spectroscopic…
Massive Hypervelocity Runaway Stars in the Large Magellanic Cloud
Xu, Ye; Liu, Dejian; Hao, Chaojie +3 more
Since the hypervelocity stars were discovered in the Milky Way, various mechanisms have been proposed to explain these runaway stars. Up to now, however, the dominant ejected mechanism of hypervelocity stars is still unclear. As the largest and closest face-on satellite galaxy of the Milky Way, the Large Magellanic Cloud (LMC) serves as a good tar…