Search Publications
Identifying and characterising the population of hot sub-luminous stars with multi-colour MeerLICHT data
Groot, P. J.; Aerts, C.; Ranaivomanana, P. +9 more
Context. Colour-magnitude diagrams reveal a population of blue (hot) sub-luminous objects with respect to the main sequence. These hot sub-luminous stars are the result of evolutionary processes that require stars to expel their obscuring, hydrogen-rich envelopes to reveal the hot helium core. As such, these objects offer a direct window into the …
A search for missing radio sources at z ≳ 4 using Lyman dropouts
Norris, Ray P.; Hopkins, Andrew M.; Shabala, Stanislav S. +5 more
Using the Lyman Dropout technique, we identify 148 candidate radio sources at z ≳ 4-7 from the 887.5 MHz Australian Square Kilometre Array Pathfinder (ASKAP) observations of the GAMA23 field. About 112 radio sources are currently known beyond redshift z ~ 4. However, simulations predict that hundreds of thousands of radio sources exist in that red…
Predicting light curves of RR Lyrae variables using artificial neural network based interpolation of a grid of pulsation models
Marconi, Marcella; Das, Susmita; Kanbur, Shashi M. +4 more
We present a new technique to generate the light curves of RRab stars in different photometric bands (I and V bands) using artificial neural networks (ANN). A pre-computed grid of models was used to train the ANN, and the architecture was tuned using the I-band light curves. The best-performing network was adopted to make the final interpolators i…
CHEOPS's hunt for exocomets: photometric observations of 5 Vul
Lecavelier Des Etangs, Alain; Zieba, Sebastian; Rebollido, Isabel +3 more
The presence of minor bodies in exoplanetary systems is in most cases inferred through infrared excesses, with the exception of exocomets. Even if over 35 yr have passed since the first detection of exocomets around β Pic, only ~25 systems are known to show evidence of evaporating bodies, and most of them have only been observed in spectroscopy. W…
Morpho-kinematic and photoionization models of the multipolar structures in planetary nebula NGC 6572
Parthasarathy, Mudumba; Das, Ramkrishna; Kar, Subhajit +1 more
We have studied planetary nebula (PN) NGC 6572 through 3D morpho-kinematic and photoionization modelling. The 3D morphology is reconstructed from the Hubble Space Telescope images in different narrow-band filters and position-velocity spectra. The PN has a multipolar morphology consisting of highly collimated outflows. The nebular image shows sign…
Diving into the magnetosphere of the Of?p star HD 108
Neiner, Coralie; Nazé, Yaël; Rauw, Gregor +1 more
We analyse optical and X-ray spectroscopy of the Of?p star HD 108, known for its strong dipolar magnetic field and its optical line profile variability with a time-scale of 54 ± 3 yrs, interpreted as the stellar rotation period. Optical emission lines have now recovered from their minimum emission state reached in 2007-2008. The variations of the …
Influence of Intermittency on the Energy Transfer Rate of Solar Wind Turbulence
Wang, Xin; Yuan, Zhigang; Huang, Shiyong +2 more
The intermittency in the solar wind turbulence manifests itself in the anisotropic scaling due to the anisotropic spectral index and the intermittent level based on the extended P model. However, the influence of intermittency on the energy transfer rate remains unclear. Here we apply the partial variance of increments method to identify the inter…
The 3D kinematics of stellar substructures in the periphery of the Large Magellanic Cloud
Erkal, Denis; Belokurov, Vasily; Aguado, David S. +4 more
We report the 3D kinematics of 27 Mira-like stars in the northern, eastern, and southern periphery of the Large Magellanic Cloud (LMC), based on Gaia proper motions and a dedicated spectroscopic follow-up. Low-resolution spectra were obtained for more than 40 Mira-like candidates, selected to trace known substructures in the LMC periphery. Radial …
The evolution of Martian fissure eruptions and their plumbing systems
Pieterek, Bartosz; Jones, Thomas J.
On Earth, the investigation of fissure eruptions and their deposits provide fundamental insights into the evolution of the subsurface volcanic plumbing system. On Mars, we have limited evidence of the spatiotemporal evolution of fissure-fed volcanic systems, and thus the processes operating within their subsurface-feeding dykes remain poorly under…
IP Lyn: A Totally Eclipsing Contact Binary with an Extremely Low Mass Ratio
Meng, Zi-Bin; Yu, Yun-Xia; Hu, Ke +4 more
We present the first photometric and orbital period investigations for a neglected totally eclipsing contact binary IP Lyn. The photometric solutions derived from both ground-based and several surveys' observations suggest that it is a shallow contact binary with an extremely low mass ratio of 0.055. The weak asymmetry observed in our multiple ban…