Search Publications
A search for variable subdwarf B stars in TESS full frame images - I. Variable objects in the southern ecliptic hemisphere
Sahoo, S. K.; Baran, A. S.; Ostrowski, J. +1 more
We report the results of our search for pulsating subdwarf B stars in full frame images, sampled at 30 min cadence and collected during Year 1 of the TESS mission. Year 1 covers most of the southern ecliptic hemisphere. The sample of objects we checked for pulsations was selected from a subdwarf B stars data base available to public. Only two posi…
Search for decaying eV-mass axion-like particles using gamma-ray signal from blazars
Neronov, A.; Semikoz, D.; Korochkin, A.
Decaying axion-like particles (ALP) with masses in the eV range which might occupy dark matter halos of the Milky Way and other galaxies produce a characteristic "bump" feature in the spectrum of extragalactic background light (EBL). This feature leaves an imprint on the gamma-ray spectra of distant extragalactic sources. We derive constraints on …
Time variability of the Enceladus plumes: Orbital periods, decadal periods, and aperiodic change
Ingersoll, Andrew P.; Ewald, Shawn P.; Trumbo, Samantha K.
The Enceladus plumes vary on a number of timescales. Tidal stresses as Enceladus revolves in its eccentric orbit lead to a periodic diurnal variation in the mass and velocity of solid particles in the plume. Tidal stresses associated with an orbital resonance with Dione lead to a periodic decadal variation. Aperiodic variations occur on time scale…
Correcting for chromatic stellar activity effects in transits with multiband photometric monitoring: application to WASP-52
Granzer, T.; Mallonn, M.; Ribas, I. +5 more
Context. The properties, distribution, and evolution of inhomogeneities on the surface of active stars, such as dark spots and bright faculae, significantly influence the determination of the parameters of an orbiting exoplanet. The chromatic effect they have on transmission spectroscopy, for example, could affect the analysis of data from future …
Establishing Earth's Minimoon Population through Characterization of Asteroid 2020 CD3
Fedorets, Grigori; Granvik, Mikael; Schwamb, Megan E. +20 more
We report on our detailed characterization of Earth's second known temporary natural satellite, or minimoon, asteroid 2020 CD3. An artificial origin can be ruled out based on its area-to-mass ratio and broadband photometry, which suggest that it is a silicate asteroid belonging to the S or V complex in asteroid taxonomy. The discovery o…
Asteroid lightcurve inversion with Bayesian inference
Cellino, A.; Muinonen, K.; Penttilä, A. +2 more
Context. We assess statistical inversion of asteroid rotation periods, pole orientations, shapes, and phase curve parameters from photometric lightcurve observations, here sparse data from the ESA Gaia space mission (Data Release 2) or dense and sparse data from ground-based observing programs.
Aims: Assuming general convex shapes, we develop…
Diffusion in unimodular gravity: Analytical solutions, late-time acceleration, and cosmological constraints
Corral, Cristóbal; Cruz, Norman; González, Esteban
Unimodular gravity is an appealing approach to address the cosmological constant problem. In this scenario, the vacuum energy density of quantum fields does not gravitate and the cosmological constant appears merely as an integration constant. Recently, it has been shown that energy diffusion that may arise in quantum gravity and in theories with …
The Drivers of Active Region Outflows into the Slow Solar Wind
Golub, Leon; Winebarger, Amy R.; Warren, Harry P. +13 more
Plasma outflows from the edges of active regions have been suggested as a possible source of the slow solar wind. Spectroscopic measurements show that these outflows have an enhanced elemental composition, which is a distinct signature of the slow wind. Current spectroscopic observations, however, do not have sufficient spatial resolution to disti…
The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. I. Survey Overview and First Results for Andromeda I
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +10 more
An optical monitoring survey in nearby dwarf galaxies was carried out with the 2.5 m Isaac Newton Telescope. Fifty-five dwarf galaxies and four isolated globular clusters in the Local Group were observed with the Wide Field Camera. The main aims of this survey are to identify the most evolved asymptotic giant branch (AGB) stars and red supergiants…
Trans-iron Ge, As, Se, and heavier elements in the dwarf metal-poor stars HD 19445, HD 84937, HD 94028, HD 140283, and HD 160617
Spite, M.; Barbuy, B.; Peterson, R. C.
Context. The spectra of unevolved metal-poor halo stars uniquely reflect the elemental abundances incorporated during the earliest Galactic epoch. Their heavy-element content is well understood as the products of neutron capture on iron-peak elements. However, for the lightest trans-iron elements with atomic number 30 < Z < 52, they show str…