Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · astro-ph/0301115

UBVRI Night sky brightness during sunspot maximum at ESO-Paranal

Ferdinando Patat
View original source ↗Read source document ↗Export metadata ↓

Abstract

In this paper we present and discuss for the first time a large data set of UBVRI night sky brightness measurements collected at ESO-Paranal from April 2000 to September 2001. A total of about 3900 images obtained on 174 different nights with FORS1 were analysed using an automatic algorithm specifically designed for this purpose. This led to the construction of an unprecedented database that allowed us to study in detail a number of effects such as differential zodiacal light contamination, airmass dependency, daily solar activity and moonlight contribution. Particular care was devoted to the investigation of short time scale variations and micro-auroral events. The typical dark time night sky brightness values found for Paranal are similar to those reported for other astronomical dark sites at a similar solar cycle phase. The zenith-corrected values averaged over the whole period are 22.3, 22.6, 21.6 20.9 and 19.7 mag arcsec-2 in U, B, V, R and I respectively. In particular, there is no evidence of light pollution either in the broadband photometry or in the high-airmass spectra we have analysed. Finally, possible applications for the exposure time calculators are discussed.

Explore related subjects

astro-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ferdinando Patat. 2003-01-07. UBVRI Night sky brightness during sunspot maximum at ESO-Paranal. https://doi.org/10.1051/0004-6361%3A20030030

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2024

Deformation procedure for scalar fields in cosmology

This work offers an extension of the deformation procedure introduced in field theory to the case of standard cosmology in the presence of real scalar field in flat space-time. The procedure is shown to work for many models, which give rise to several different cosmic scenarios, evolving under the presence of first-order differential equations which solve the corresponding equations of motion very appropriately.

astro-ph↗
arXiv2023

Dark Energy is the Cosmological Quantum Vacuum Energy of Light Particles-The Axion and the Lightest Neutrino

We uncover the general mechanism producing the dark energy(DE). This is only based on well known quantum physics and cosmology. We show that the observed DE originates from the cosmological quantum vacuum of light particles which provides a continuous energy distribution able to reproduce the data. Bosons give positive contributions to the DE while fermions yield negative contributions. As usual in field theory, ultraviolet divergences are subtracted from the physical quantities. The subtractions respect the symmetries of the theory and we normalize the physical quantities to be zero for the Minkowski vacuum. The resulting finite contributions to the energy density and the pressure from the quantum vacuum grow as log a(t) where a(t) is the scale factor, while the particle contributions dilute as 1/a^3(t), as it must be for massive particles. The DE equation of state P = w(z)H turns to be w(z)<-1 with w(z) asymptotically reaching the value -1 from below.A scalar particle can produce the observed DE through its quantum cosmological vacuum provided:(i)its mass is of the order of 10^{-3} eV = 1 meV,(ii) it is very weakly coupled and (iii) it is stable on the time scale of the age of the universe. The axion vacuum thus appears as a natural candidate. The neutrino vacuum (especially the lightest mass eigenstate) can give negative contributions to the DE. We find that w(z=0) is slightly below -1 by an amount ranging from [-1.5 10^{-3}] to [-8 10^{-3}] and we predict the axion mass to be in the range between 4 and 5 meV. We find that the universe will expand in the future faster than the de Sitter universe, as an exponential in the square of the cosmic time. DE arises from the quantum vacua of light particles in FRW cosmological space time in an analogous way to the Casimir effect in Minkowski spacetime with non trivial boundaries.

astro-ph↗