Give Me a Few Hours: Exploring Short Timescales in Rubin Observatory Cadence Simulations

The limiting temporal resolution of a time-domain survey in detecting transient behavior is set by the time between observations of the same sky area. We analyze the distribution of visit separations for a range of Vera C. Rubin Observatory cadence simulations. Simulations from families v1.5–v1.7.1 are strongly peaked at the 22 minute visit pair separation and provide effectively no constraint on temporal evolution within the night. This choice will necessarily prevent Rubin from discovering a wide range of astrophysical phenomena in time to trigger rapid follow-up. We present a science-agnostic metric to supplement detailed simulations of fast-evolving transients and variables and suggest potential approaches for improving the range of timescales explored.

Designing a New Space-borne Interferometer to Probe the History of Our Universe

Scientists present a new design for a space-born laser interferometer that could detect gravitational waves below 10 Hz, letting us probe into new astrophysical phenomena.

A catalogue of over 10 million variable source candidates in ZTF Data Release 1

ABSTRACT Variable sources probe a wide range of astrophysical phenomena. We present a catalogue of over 10 million variable source candidates found in Data Release 1 (DR1) of the Zwicky Transient Facility (ZTF). We perform a periodicity search up to a frequency of 160 d−1, and we classify the light curves into erratic and smooth variables. We also present variability indicators and the results of a periodicity search, up to a frequency of 5 d−1, for about 1 billion sources in the ZTF-DR1 light curve data base. We present several new short-period (<90 min) candidates, and about 60 new dwarf nova candidates, including two candidate eclipsing systems. Both the 10 million variables catalogue and ∼1 billion source catalogue are available online in catsHTM format.

Virtual and Augmented Reality for increasing the awareness of current scientific research

<p dir="ltr">Virtual reality (VR) devices allow the exploration of 3D data in a fully immersive fashion and make it possible to create a powerful engagement experience and a direct interaction with current scientific data to learn more about astronomy in Education and Public Outreach (E&PO) activities. In 2019 the INAF Osservatorio Astronomico di Palermo (INAF-OAPa) launched <em>3DMAP-VR</em> (3-Dimensional Modeling of Astrophysical Phenomena in Virtual Reality; Orlando et al. 2019, RNAAS 3, ID.176), a project for visualizing 3D results of astrophysical (magneto)-hydrodynamic (MHD) simulations, through VR equipments. The models, uploaded on the Sketchfab portal (a platform widely used to publish and share 3D models and VR contents), received a very positive feedback from the scientific community and the general public.  Here we will show some of the scenes produced in the framework of 3DMAP-VR  to describe astrophysical phenomena. More specifically, we will focus our attention on MHD simulations describing the interaction of exoplanets (https://skfb.ly/6QYtC) with their host stars, and on artististic views of exoplanets which are based on information extracted from multi-wavelength observations, such as in the case of exoplanets 55 Cancri (https://skfb.ly/6R6Pt) and Wasp-76b (https://skfb.ly/6QZHF). Moreover, the 3DMAP-VR project team used augmented reality to produce informative videos to explore the characteristics of some of these models, published on <em>media.inaf.it</em> and <em>edu.inaf.it</em>. These E&PO products not only allowed the public to understand the astrophysical phenomena but they have stimulated great synergy between the outreach team and the astronomers, and between researchers and the public.</p>

On optical transmittance of ultra diluted gas

The paper proposes a model of optical transmittance of ultra diluted gas taking into account gas particles non-locality, the quantum effect of wave function spreading derived from solving the Schr ̈odinger equation for a free particle. A significant increase in the transmittance of such gas is envisaged as compared to the classical predictions. Some quantitative and qualitative consequences of the model are indicated and falsifying experiments are proposed. The classic Beer-Lambert law equation within range of its applicability is derived from the model. Remarks to some astrophysical phenomena and possible interpretations of Quantum Mechanics are made. An experiment consistent with the predictions of this model is referenced.

Production of monopole–antimonopole pairs in very intense but slowly varying magnetic field

The production of pairs of monopole–antimonopole in presence of extremely intense magnetic fields, is briefly investigated in the case where the magnetic field undergoes also a time variation. The possibility that similar conditions are realized, with a production of ordinary particles, was already considered for astrophysical phenomena, e.g. some phases of evolution of neutron stars.

Recent highlights on neutrino-nucleus interactions

The recent developments on neutrino-nucleus interactions at low and intermediate energies are reviewed and discussed in conjunction with the recent data of atmospheric, solar, and accelerator neutrino experiments. The theoretical nuclear physics approaches used to interpret and predict phenomena for which neutrinos play a crucial role are also investigated. We emphasize on the implications of neutrino reactions and properties into the astrophysical phenomena and atmospheric neutrino problems.

Impossible moons - transit timing effects that cannot be due to exomoon

Exomoons are predicted to produce transit timing variations (TTVs) upon their host planet. Unfortunately, so are many other astrophysical phenomena - most notably other planets in the system. In this work, an argument of reductio ad absurdum is invoked, by deriving the transit timing effects that are impossible for a single exomoon to produce. Our work derives three key analytic tests. First, one may exploit the fact that a TTV signal from an exomoon should be accompanied by transit duration variations (TDVs), and that one can derive a TDV floor as a minimum expected level of variability. Cases for which the TDV upper limit is below this floor can thus be killed as exomoon candidates. Second, formulae are provided for estimating whether moons are expected to be "killable" when no TDVs presently exist, thus enabling the community to estimate the value of deriving TDVs beforehand. Third, a TTV ceiling is derived, above which exomoons should never be able to produce TTV amplitudes. These tools are applied to a catalog of TTVs and TDVs for two and half thousand Kepler Objects of Interest, revealing over two hundred cases that cannot be due to a moon - remarkably then a large fraction of the known TTV amplitudes are consistent with being caused by a moon. These tests are also applied to the exomoon candidate Kepler-1625b i, which comfortably passes the criteria. These simple analytic results should provide a means of rapidly rejecting putative exomoons and streamlining the search for satellites.