Conveners
Parallel Session: Compact objects, Stars, & Planets
- Ignas Snellen
M-dwarfs are thought to be hostile environments for exoplanets. Stellar events are very common on such stars. These events might cause the atmospheres of exoplanets to change significantly over time. It is not only the major stellar flare events that contribute to this disequilibrium, but the smaller flares might also affect the atmospheres in an accumulating manner. In this study, we aim to...
The total disk gas mass and elemental C, N, O composition of a protoplanetary disk are crucial ingredients for our understanding of planet formation. Measuring the gas mass is complicated as we lack the far-IR facilities necessary to observe HD, and the elemental abundances with respect to hydrogen are degenerate with gas mass in all disk models. We determined the gas mass and elemental...
In this talk, I will discuss results from radio timing observations of the black widow binary pulsar J0610-2100 and optical observations of its binary companion. The radio timing observations extend the timing baseline to 16 yr and reveal a marginal detection of the orbital period derivative, but they show no significant evidence of orbital variations such as those seen in other black widow...
Atmospheric dispersion, the wavelength dependent differential refraction of light passing through the atmosphere, will cause severe degradation of image quality and contrast on the upcoming Extremely Large Telescope (ELT). Although the effect is the most severe at short wavelengths and low observing altitudes, the high resolution of the ELT causes atmospheric dispersion to be a problem well...
Since the day of its explosion, supernova (SN) 1987A has been closely monitored to study its evolution and to detect its central compact relic. In fact, the formation of a neutron star is strongly supported by the detection of neutrinos from the SN. However, besides the detection in the Atacama Large Millimeter/submillimeter Array (ALMA) data of a feature that is somehow compatible with the...
For its numerous effects on the evolution of a galaxy, dust has been studied in detail ever since its discovery. Visible in emission in the infrared regime, its spectral energy distribution is a powerful tracer of many properties, when fit by physical dust models. There remains however a property of dust grains that has not yet been poked at extensively, potentially retaining some crucial...
Water ice has been found to be ubiquitous in quiescent molecular clouds and star-forming regions. It is formed on the surface of tiny dust grains located in cold environments (~10K). Satellite missions have concluded that water enters protoplanetary disks mostly as ice, and may later be delivered to planets. This emphasizes the need of knowing the basic properties of water ice, which will be...
Recently an unexpected UV afterglow was reported for the Fast Blue Optical Transient AT2018cow. The most supported explanation for this event is currently a peculiar supernova, although other theories cannot be ruled out. Supernovae are expected to become redder over time, and not much research has gone into potential UV afterglows of such events. We investigate whether there are UV afterglows...
Planetesimal formation in protoplanetary disks is still one of the major open questions in planet formation theory. It is known that solids can’t grow up to asteroid size relying on sticking after pairwise collisions only, due to the fragmentation barrier and the drift barrier. A possible solution is to form dense particle clumps, with low velocity-dispersion, that can then collapse under...
