1k citations · 6k across the 136 of their papers we have counts for
140 papers
Transients and Stellar Activity as Revealed by Ultraviolet Diagnostic Tracers
Richard de Grijs, Martin A. Barstow, Deepak Chahal +5
Ultraviolet (UV) observations offer unique insights into transient and variable astrophysical phenomena, from the Sun and nearby stars to supernovae and star-forming galaxies. Here…
Investigating the Young Stellar Populations and Hierarchies in Nearby Galaxies with the UVIT. III. Evidence for a Largest Scale of Correlated Stellar Structures and a Non-universal Fractal Dimension
Gairola Shashank, Smitha Subramanian, Shyam H. Menon +5
Scale-free turbulent motions, gravitational collapse and galactic dynamics govern galactic-scale, hierarchical organization of star formation (SF) within galaxies. Past studies sug…
Deep VISTA observations of the Magellanic Clouds (VMCDeep)
M. -R. L. Cioni, A. O. Omkumar, N. J. G. Cross +28
The central regions of galaxies challenge observers with a high density of stars, gas and dust. The LMC hosts a dense stellar bar whereas the SMC hosts a dense core, which have elu…
Star Clusters in the Ultraviolet
Annapurni Subramaniam, Samyaday Choudhury, Richard de Grijs +5
Ultraviolet (UV) observations provide a powerful window into the hot and evolved stellar populations that shape the structure, evolution and integrated light of star clusters. Beca…
The VMC survey -- LV. The coherent expansion of the SMC
S. Vijayasree, F. Niederhofer, M. -R. L. Cioni +8
The Small Magellanic Cloud (SMC) exhibits significant kinematic disequilibrium due to interactions with the Large Magellanic Cloud (LMC). Here, we investigate the two-dimensional s…
Fifty years of primordial helium abundances: A statistical reanalysis
Nabil Husain, Richard de Grijs, Giuseppe Bono
The primordial helium mass fraction, , is a key observational pillar of Big Bang nucleosynthesis and a sensitive probe of early-Universe physics. Over the past severa…
The GALAH Survey: Neutron-Capture Elemental Abundances for 350,000 Gaia-RVS spectra and the Chemodynamics of Accreted Structures
Pradosh Barun Das, Daniel B. Zucker, Aldo Mura-Guzmán +15
We present a comprehensive data-driven spectroscopic analysis of 357,415 red giant stars using Gaia DR3 Radial Velocity Spectrometer (RVS) spectra (8460-8700 A; ),…
Optical spectroscopic signatures of the red giant evolutionary state
Ella Xi Wang, Melissa Ness, Thomas Nordlander +17
Modern spectroscopic surveys output large data volumes. Theoretical models provide a means to transform the information encoded in these data to measurements of physical stellar pr…
Photometric activity cycles in fast-rotating stars: Revisiting the reality of stellar activity cycle branches
Deepak Chahal, Devika Kamath, Richard de Grijs +2
We aim to detect activity cycles in young main-sequence stars, analogous to the 11-year solar cycle, using combined photometric survey data. This research will enhance our understa…
The HASHTAG project II. Giant molecular cloud properties across the M31 disc
Yikai Deng, Zongnan Li, Zhiyuan Li +17
We present a study of giant molecular cloud (GMC) properties in the Andromeda galaxy (M31) using CO(3-2) data from the James Clerk Maxwell Telescope (JCMT) in selected regions acro…
An automated method to detect and characterise semi-resolved star clusters
Amy E. Miller, Zachary Slepian, Elizabeth A. Lada +8
We present a novel method for automatically detecting and characterising semi-resolved star clusters: clusters where the observational point-spread function (PSF) is smaller than t…
The GALAH Survey: Stellar parameters and abundances for 800,000 Gaia RVS spectra using GALAH DR4 and The Cannon
Pradosh Barun Das, Daniel B. Zucker, Gayandhi M. De Silva +15
Analysing stellar parameters and abundances from nearly one million Gaia Data Release 3 (DR3) Radial Velocity Spectrometer (RVS) spectra poses challenges due to the limited spectra…
All roads lead to (New) Rome: Byzantine astronomy and geography in a rapidly changing world
Richard de Grijs
During the first few centuries CE, the centre of the known world gradually shifted from Alexandria to Constantinople. Combined with a societal shift from pagan beliefs to Christian…
New quasars behind the Magellanic Clouds. II. Spectroscopic confirmation of 136 near-infrared selected candidates
Valentin D. Ivanov, Maria-Rosa L. Cioni, Michel Dennefeld +6
Quasi-stellar objects (QSOs) are a basis for an absolute reference system for astrometric studies. There is a need for creating such system behind nearby galaxies, to facilitate th…
The Origin of Young Stellar Populations in NGC 1783: Accretion of External Stars
Li Wang, Licai Deng, Xiaoying Pang +4
The presence of young stellar populations in the Large Magellanic Cloud cluster NGC 1783 has caught significant attention, with suggestions ranging from it being a genuine secondar…
The GALAH survey: Elemental abundances in open clusters using joint effective temperature and surface gravity photometric priors
Kevin L. Beeson, Janez Kos, Richard de Grijs +10
The ability to measure precise and accurate stellar effective temperatures () and surface gravities () is essential in determining accurate and precise abund…
The VMC Survey -- L. Type II Cepheids in the Magellanic Clouds
Teresa Sicignano, Vincenzo Ripepi, Marcella Marconi +9
Type II Cepheids (T2C) are less frequently used counterparts of classical Cepheids which provide the primary calibration of the distance ladder for measuring in the local Uni…
Extended Main Sequences in Star Clusters
Chengyuan Li, Antonino P. Milone, Weijia Sun +1
Extended main sequences (eMSs) and extended main-sequence turnoffs (eMSTOs) are fascinating phenomena that are routinely observed in star clusters. These phenomena strongly challen…
The role of tidal interactions in the formation of slowly rotating early-type stars in young star clusters
Chenyu He, Chengyuan Li, Weijia Sun +9
The split main sequences found in the colour-magnitude diagrams of star clusters younger than ~600 Myr are suggested to be caused by the dichotomy of stellar rotation rates of uppe…
Unravelling the Period Gap using LAMOST Chromospheric Activity Indices
Deepak Chahal, Devika Kamath, Richard de Grijs +2
In our recent catalogue of BY Draconis (BY Dra) variables based on Zwicky Transient Facility data, we found traces of a period gap in the period-colour diagram. We combined our BY…
Kinematics of stellar substructures in the Small Magellanic Cloud
Dalal El Youssoufi, Maria-Rosa L. Cioni, Nikolay Kacharov +6
We present a kinematic analysis of the Small Magellanic Cloud using 3700 spectra extracted from the European Southern Observatory archive. We used data from Gaia and near-infrared…
The Cosmology of David Bohm: Scientific and Theological Significance
Richard de Grijs, Doru Costache
We discuss David Bohm's dual contributions as a physicist and thinker. First, de Grijs introduces Bohm's universe, with an emphasis on the physical quest that led Bohm to the elabo…
Early Star Charts of the Dutch East India Company
Richard de Grijs
As the European maritime powers expanded their reach beyond north Atlantic coastal waters to distant lands as far away as the East Indies, access to a practical means of maritime n…
Precise Empirical Determination of Metallicity Dependence of Near-infrared Period-Luminosity Relations for RR Lyrae Variables
Anupam Bhardwaj, Marcella Marconi, Marina Rejkuba +9
RR Lyrae variables are excellent population II distance indicators thanks to their well-defined period-luminosity relations (PLRs) at infrared wavelengths. We present results of ne…