|   | 
Details
   web
Records
Author Simoneau, A.; Aubé, M.; Bertolo, A.
Title Multispectral analysis of the night sky brightness and its origin for the Asiago Observatory, Italy Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 491 Issue 3 Pages 4398-4405
Keywords Skyglow; light pollution; numerical methods; Site testing; Italy; Observatories
Abstract Night protection has been a major concern for astronomers since the electrification of cities and is beginning to be recognized as a major environmental problem. In recent years, regulations have been put in place through the establishment of Dark Sky Reserves that impose stringent constraints on lighting practices for cities in protected areas. Astronomers from the Asiago Observatory, located in the Veneto region of Italy, would like to create an area of this nature around their facilities to improve and protect the quality of their astronomical observations. This study assesses the current state of the sky in the region through numerical modelling using the latest improvements to the ILLUMINA model and aims to identify the main contributing sources of artificial light. The explicit calculation of the contribution of private residential lighting helps to discern the origin of the light. We also present a new approach for extracting an estimate of the distribution of lamp technology in a region from images taken from the International Space Station.
Address Bishop’s University, 2600 rue College, Sherbrooke, Québec J1M 1Z7, Canada; alsimoneau(at)gmail.com
Corporate Author Thesis
Publisher (down) Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2790
Permanent link to this record
 

 
Author Bará, S.; Aubé, M.; Barentine, J.; Zamorano, J.
Title Magnitude to luminance conversions and visual brightness of the night sky Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal MNRAS
Volume 493 Issue 2 Pages 2429–2437
Keywords Skyglow; light pollution; atmospheric effects; techniques: photometric; methods: numerical; luminance
Abstract The visual brightness of the night sky is not a single-valued function of its brightness in other photometric bands, because the transformations between photometric systems depend on the spectral power distribution of the skyglow. We analyze the transformation between the night sky brightness in the Johnson-Cousins V band (mV, measured in magnitudes per square arcsecond, mpsas) and its visual luminance (L, in SI units cd m−2) for observers with photopic and scotopic adaptation, in terms of the spectral power distribution of the incident light. We calculate the zero-point luminances for a set of skyglow spectra recorded at different places in the world, including strongly light-polluted locations and sites with nearly pristine natural dark skies. The photopic skyglow luminance corresponding to mV = 0.00 mpsas is found to vary between 1.11–1.34 × 105 cd m−2 if mV is reported in the absolute (AB) magnitude scale, and between 1.18–1.43 × 105 cd m−2 if a Vega scale for mV is used instead. The photopic luminance for mV = 22.0 mpsas is correspondingly comprised between 176 and 213 μcd m−2 (AB), or 187 and 227 μcd m−2 (Vega). These constants tend to decrease for increasing correlated color temperatures (CCT). The photopic zero-point luminances are generally higher than the ones expected for blackbody radiation of comparable CCT. The scotopic-to-photopic luminance ratio (S/P) for our spectral dataset varies from 0.8 to 2.5. Under scotopic adaptation the dependence of the zero-point luminances with the CCT, and their values relative to blackbody radiation, are reversed with respect to photopic ones.
Address Departamento de Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia; salva.bara(at)usc.gal
Corporate Author Thesis
Publisher (down) Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2825
Permanent link to this record
 

 
Author Masana, E.; Carrasco, J.M.; Bará, S.; Ribas, S.J.
Title A multiband map of the natural night sky brightness including Gaia and Hipparcos integrated starlight Type Journal Article
Year 2021 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 501 Issue 4 Pages 5443-5456
Keywords Instrumentation; night sky brightness; radiative transfer; scattering; atmospheric effects; photometers; light pollution; site testing
Abstract The natural night sky brightness is a relevant input for monitoring the light pollution evolution at observatory sites, by subtracting it from the overall sky brightness determined by direct measurements. It is also instrumental for assessing the expected darkness of the pristine night skies. The natural brightness of the night sky is determined by the sum of the spectral radiances coming from astrophysical sources, including zodiacal light, and the atmospheric airglow. The resulting radiance is modified by absorption and scattering before it reaches the observer. Therefore, the natural night sky brightness is a function of the location, time, and atmospheric conditions. We present in this work the GAia Map of the Brightness Of the Natural Sky (GAMBONS), a model to map the natural night brightness of the sky in cloudless and moonless nights. Unlike previous maps, GAMBONS is based on the extra-atmospheric star radiance obtained from the Gaia catalogue. The Gaia-Data Release 2 (DR2) archive compiles astrometric and photometric information for more than 1.6 billion stars up to G = 21 mag. For the brightest stars, not included in Gaia-DR2, we have used the Hipparcos catalogue instead. After adding up to the star radiance the contributions of the diffuse galactic and extragalactic light, zodiacal light and airglow, and taking into account the effects of atmospheric attenuation and scattering, the radiance detected by ground-based observers can be estimated. This methodology can be applied to any photometric band, if appropriate transformations from the Gaia bands are available. In particular, we present the expected sky brightness for V (Johnson), and visual photopic and scotopic passbands.
Address Departament Física Quàntica i Astrofìsica, Institut de Ciències del Cosmos (ICC-UB-IEEC), C Martí Franquès 1, E-08028 Barcelona, Spain; emasana ( at ) fqa.ub.edu
Corporate Author Thesis
Publisher (down) Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 3299
Permanent link to this record
 

 
Author Kocifaj, M.; Bará, S.
Title Night-time monitoring of the aerosol content of the lower atmosphere by differential photometry of the anthropogenic skyglow Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society: Letters Abbreviated Journal
Volume 500 Issue 1 Pages L47-L51
Keywords Skyglow; radiative transfer; scattering; atmospheric effects; instrumentation; photometers; light pollution
Abstract Night-time monitoring of the aerosol content of the lower atmosphere is a challenging task, because appropriate reference natural light sources are lacking. Here, we show that the anthropogenic night-sky brightness due to city lights can be successfully used for estimating the aerosol optical depth of arbitrarily thick atmospheric layers. This method requires measuring the zenith night-sky brightness with two detectors located at the limiting layer altitudes. Combined with an estimate of the overall atmospheric optical depth (available from ground-based measurements or specific satellite products), the ratio of these radiances provides a direct estimate of the differential aerosol optical depth of the air column between these two altitudes. These measurements can be made with single-channel low-cost radiance detectors widely used by the light pollution research community.
Address Faculty of Mathematics, Physics, and Informatics, Comenius University, Mlynská dolina, 842 48 Bratislava, Slovakia ICA, Slovak Academy of Sciences, Dúbravská cesta 9, 845 03 Bratislava, Slovakia; kocifaj ( at ) savba.sk
Corporate Author Thesis
Publisher (down) Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1745-3925 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 3302
Permanent link to this record
 

 
Author Cavazzani, S.; Ortolani, S.; Bertolo, A.; Binotto, R.; Fiorentin, P.; Carraro, G.; Zitelli, V.
Title Satellite measurements of artificial light at night: aerosol effects Type Journal Article
Year 2020 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 499 Issue 4 Pages 5075-5089
Keywords Instrumentation; atmospheric effects; detectors; light pollution; site testing; Aerosols
Abstract The study of artificial light at night (ALAN) by satellite is very important for the analysis of new astronomical sites and for the long-term temporal evolution observation of the emission from the ground. The analysis of satellite data presents many advantages but also some critical points because of fluctuations in measurements. The main result of this paper is the discovery of a correlation between these fluctuations and the aerosol concentration combined with cloud cover and lunar cycles. In this work, we also present a mathematical empirical model for the light pollution propagation study in relation to the aerosol concentration detected by satellite. We apply this model to the astronomical site of Asiago (Ekar Observatory) providing a possible explanation for the temporal ALAN fluctuations detected by satellite. Finally, we validate the results with the ground collected data.
Address Department of Physics and Astronomy, University of Padova, Vicolo dell’Osservatorio 3, I-35122 Padova, Italy; stefano.cavazzani ( at ) unipd.it
Corporate Author Thesis
Publisher (down) Oxford Academic Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 3310
Permanent link to this record