Search Publications
Space debris observations with the Slovak AGO70 telescope: Astrometry and light curves
Šilha, Jiří; Krajčovič, Stanislav; Zigo, Matej +12 more
The Faculty of Mathematics, Physics and Informatics of Comenius University in Bratislava, Slovakia (FMPI) operates its own 0.7-m Newtonian telescope (AGO70) dedicated to the space surveillance tracking and research, with an emphasis on space debris. The observation planning focuses on objects on geosynchronous (GEO), eccentric (GTO and Molniya) an…
Do bulges stop stars forming?
Eales, Stephen; Eales, Oliver; de Vis, Pieter
In this paper, we use the Herschel Reference Survey to make a direct test of the hypothesis that the growth of a stellar bulge leads to a reduction in the star formation efficiency of a galaxy (or conversely a growth in the gas-depletion time-scale) as a result of the stabilization of the gaseous disc by the gravitational field of the bulge. We fi…
Sporadic and intense accretion in a 1 Myr-old brown dwarf candidate
Bessell, M. S.; Murphy, S. J.; Nguyen-Thanh, D. +1 more
Context. Studying the accretion process in very low-mass objects has important implications for understanding their formation mechanism. Many nearby late-M dwarfs that have previously been identified in the field are in fact young brown dwarf members of nearby young associations. Some of them are still accreting. They are therefore excellent targe…
Dynamical Mass Estimates of the β Pictoris Planetary System through Gaussian Process Stellar Activity Modeling
Vandal, Thomas; Doyon, René; Rameau, Julien
Nearly 15 yr of radial velocity (RV) monitoring and direct imaging enabled the detection of two giant planets orbiting the young, nearby star β Pictoris. The δ Scuti pulsations of the star, which overwhelm planetary signals, need to be carefully suppressed. In this work, we independently revisit the analysis of the RV data following a different ap…
The nature of the symbiotic candidate 2MASS J07363415+6538548 in the field of NGC 2403
Merc, J.; Gális, R.; Wolf, M. +2 more
New Online Database of Symbiotic Variables includes several poorly characterized objects and candidate symbiotic stars, not only in the Milky Way but also in other galaxies. The goal of the research presented in this paper was to reveal the nature of 2MASS J07363415+6538548, the object discovered as an X-ray source in the field of NGC 2403, and te…
Determining the origin of the building blocks of the Ice Giants based on analogue measurements from comets
Mousis, O.; Mandt, K. E.; Treat, S.
The abundances of the heavy elements and isotopic ratios in the present atmospheres of the giant planets can be used to trace the composition of volatiles that were present in the icy solid material that contributed to their formation. The first definitive measurements of noble gas abundances and isotope ratios at comet 67P/Churyumov-Gerasimenko (…
Evolution of exploding granules from coordinated observations by THEMIS, IRIS, SDO/HMI, and HINODE, and a simulation
Malherbe, J. M.; Dalmasse, K.; Roudier, T. +3 more
Exploding granules constitute the strongest horizontal flows on the quiet Sun and contribute to the structure of the surface horizontal velocity fields which build the large-scale organization of the discrete magnetic field. In this work we explore exploding granule expansion through the observations of the ground-based THEMIS telescope, IRIS, SDO…
How to disentangle geometry and mass-loss rate from AGB-star spectral energy distributions. The case of EP Aquarii
Jorissen, A.; Decin, L.; Groenewegen, M. A. T. +2 more
Context. High-angular-resolution observations of asymptotic giant branch (AGB) stars often reveal non-spherical morphologies for the gas and dust envelopes.
Aims: We aim to make a pilot study to quantify the impact of different geometries (spherically symmetric, spiral-shaped, and disc-shaped) of the dust component of AGB envelopes on spectra…
K2-HERMES II. Planet-candidate properties from K2 Campaigns 1-13
Kane, Stephen R.; Casey, Andrew R.; Wittenmyer, Robert A. +22 more
Accurate and precise radius estimates of transiting exoplanets are critical for understanding their compositions and formation mechanisms. To know the planet, we must know the host star in as much detail as possible. We present complete results for planet-candidate hosts from the K2-HERMES survey, which uses the HERMES multi-object spectrograph on…
The Kasei Valles, Mars: a unified record of episodic channel flows and ancient ocean levels
Duran, Sergio; Coulthard, Tom J.
There is widespread evidence across Mars of past flows in major channel systems as well as more than one palaeo ocean level. However, evidence for the timing of channel flows and ocean levels is based on geographically diverse sources with a limited number of dates, making reconstructions of palaeo flows and ocean levels patchy. Here, based on hig…