Issue |
Astron. Astrophys. Suppl. Ser.
Volume 119, Number 1, October I 1996
|
|
---|---|---|
Page(s) | 153 - 170 | |
DOI | https://doi.org/10.1051/aas:1996234 | |
Published online | 15 October 1996 |
Sky brightness at the ESO La Silla Observatory 1978 to 1988 *
1
Observatory, P.O. Box 14, FIN-00014 University of Helsinki, Finland
2
Astronomisches Institut, Ruhr-Universität Bochum, D-44780 Bochum, Germany
Send offprint request to: K. Mattila
Received:
4
November
1995
Accepted:
13
January
1996
We have measured the sky brightness at the European Southern Observatory (ESO),
La Silla, during 40 moonless nights in the years 1978 - 1988. Most of
the measurements were performed in five intermediate band filters between
3500 and 5470 Å, including the Strömgren , and y bands. In addition
we made measurements in the uvgr and BVRI photometric systems.
Typically 20 to 40
readings were obtained each night at a fixed (α, δ)
position, selected
to be free of stars down to a limiting magnitude of
20. The sky
brightnesses were calibrated using standard stars. We discuss the sky
brightness variations both during individual nights and from year to year.
We have found that the long-term variations are well correlated with
the solar activity, for which the 10.7 cm radio flux is used as a measure.
We compare the sky brightnesses as observed
at La Silla with the published values for several other sites.
Finally, based on the tight correlation of the airglow variations in two pass
bands near 4000 Å we propose a new method for the separation of airglow and
zodiacal light contributions.
Key words: atmospheric effects / site testing / techniques: photometric / interplanetary medium
© European Southern Observatory (ESO), 1996