Related papers: Evidence for dynamical changes in Betelgeuse using…

Modern surveys of gravitational microlensing events have progressed to detecting thousands per year. Surveys are capable of probing Galactic structure, stellar evolution, lens populations, black hole physics, and the nature of dark matter.…

I report recent studies on the evolution of perturbations in the context of the ``pre-big-bang" scenario typical of string cosmology, with emphasis on the formation of a stochastic background of relic photons and gravitons, and its possible…

Results from the BV(RI)c photometric observations of the young stellar object V2492 Cyg collected in the period from April 2018 to September 2020 are presented. These observations are a part of our monitoring of the star that began in 2010…

We present new photometric data for seven high-amplitude delta Scuti stars. The observations were acquired between 1996 and 2002, mostly in the Johnson photometric system. For one star (GW UMa), our observations are the first since the…

We present the outcome of a highly-sensitive search for magnetic fields on the cool supergiant Betelgeuse. A time-series of six circularly-polarized spectra was obtained using the NARVAL spectropolarimeter at T\'elescope Bernard Lyot (Pic…

It is thought that the Universe went through an early period known as the Dark Ages, during which primeval density fluctuations grew to form the first luminous objects, marking the beginning of Cosmic Dawn around 100 million years after the…

In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT optical data in the BVRI bands acquired at 36 observatories around…

We uncover how nonlinearities dramatically alter the buckling of elastic beams. First, we show experimentally that sufficiently wide ordinary elastic beams and specifically designed metabeams ---beams made from a mechanical metamaterial---…

The detection of microlensing events from stars in the Large Magellanic Cloud and in the Galactic bulge raise important constraints on the distribution of dark matter and on galactic structure, although some events may be due to a new type…

In the last decade, neutrino astronomy has taken off with two major breakthroughs, the first observation of high-energy astrophysical neutrinos in 2013 and the first evidence for gamma-rays and neutrinos from a single object published in…

SuperWASP light curves for 53 W UMa-type eclipsing binary (EB) candidates, identified in previous work as being close to the contact binary short-period limit, were studied for evidence of period change. The orbital periods of most of the…

The big bang hypothesis is widely accepted despite numerous physics conflicts. It rests upon two experimental supports, galactic red shift and the cosmic microwave background. Both are produced by dark matter, shown here to be hydrogen…

New analysis on the period changes of Type II Cepheid AU Peg is presented. The available recent photometric measurements were collected and analysed with various methods. The period has been found to be constant for certain time intervals,…

The presence of a planet around the K dwarf HD192263 was recently called into question by the detection of a periodic photometric signal with the same period as the one observed in radial velocity. In this paper, we investigate this…

The abundances of mixing--sensitive elements including lithium, [C/N], and 12C/13C are known to change near the red giant branch bump. The explanation most often offered for these alterations is double diffusive thermohaline mixing in the…

SwSt 1 (PN G001.5-06.7) is a bright and compact planetary nebula containing a late [WC]-type central star. Previous studies suggested that the nebular and stellar lines are slowly changing with time. We studied new and archival optical and…

The Sun shrinks during solar maximum and regrows during solar minimum by a few kilometers. Here, we observe, for the first time, that the solar radius variation shows planetary relationship. This suggests that some remote planetary links…

The blazar TXS 0506+056 got into the spotlight of the astrophysical community in September 2017, when a high-energy neutrino detected by IceCube (IceCube-170922A) was associated at the 3 $\sigma$ level to a $\gamma$-ray flare from this…

Evidence for a spectral line in the inner Galaxy has caused a great deal of excitement over the last year, mainly because of its interpretation as a possible dark matter signal. The observation has raised important questions about…

The nearby red supergiant (RSG) Betelgeuse has a complex circumstellar medium out to at least 0.5 parsecs from its surface, shaped by its mass-loss history within the past 0.1 Myr, its environment, and its motion through the interstellar…