J/A+AS/112/99 Calar Alto Obs. sky brightness (Leinert+, 1995)
Measurements of sky brightness at the Calar Alto Observatory
Leinert C., Vaisaenen P., Mattila K., Lehtinen K.
<Astron. Astrophys. Suppl. Ser. 112, 99 (1995)>
=1995A&AS..112...99L 1995A&AS..112...99L (SIMBAD/NED BibCode)
Keywords: atmospheric effects - site testing
Description:
We report measurements of the sky brightness at the Calar Alto
Observatory during 18 moonless nights in the years 1989, 1990, 1991,
and 1993. Most of the measurements were performed in eight
intermediate band filters between 350nm and 820nm. A set of
measurements was obtained in the broad band UBVRI filters during three
nights in 1990. Typically 10 to 20 readings were obtained each night
for one or two fixed positions (fixed in α, δ), selected
to be free of stars down to a limiting magnitude of about B=20. The
sky brightnesses were calibrated using standard stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3a 58 2748 Narrow intermediate band surface photometry
table3b 58 769 UBVRI broad band surface photometric data
table3c 34 18 End and beginning of astronomical twilight
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See also:
J/A+AS/119/153 : La Silla Observatory sky brightness 1978-1988 (Mattila+ 1996)
Byte-by-byte Description of file: table3a
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Bytes Format Units Label Explanations
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3- 8 I6 "DD/MM/YY" Date Date
10- 11 I2 --- Filter [1/8] Filter number (1)
15- 21 F7.4 h LST Local sideral time
26- 33 F8.2 ct/s 2.2mTel []? 2.2m telescope measurement
37- 45 F9.2 ct/s 1.23mTel 1.23m telescope measurement
53- 58 F6.2 10-11W/m2/sr/nm SuBr Surface brightness
(10-9 ergs/s/cm2/sr/Angstroem) (2)
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Note (1): For the narrow band data the FILTERS 01 ... 08 correspond to
u (Stroemgren), 392nm, 403nm, b, 525nm, 580nm, 710nm, and 820nm,
respectively.
Note (2): See section 2.1. of the article for description of the derivation of
intensities. Summary: the ratio of 1.23m/2.2m counts (and
interpolation where needed) has been used.
An abrupt change in the intensities during a night indicates a CHANGE
OF TARGET; these are readily seen from Fig. 3. of the article.
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Byte-by-byte Description of file: table3b
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Bytes Format Units Label Explanations
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3- 8 I6 "DD/MM/YY" Date Date
10- 11 I2 --- Filter [1/5] Filter number (1)
15- 21 F7.4 h LST Local sideral time
25- 33 F9.2 ct/s 2.2mTel 2.2m telescope measurement
37- 45 F9.2 ct/s 1.23mTel 1.23m telescope measurement
52- 58 F7.2 "S_10" SuBr Surface brightness (2)
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Note (1): For the broad band data the FILTERS 01 -- 05 correspond to Johnson
bands U, B, V, R, and I, respectively.
Note (2): See section 2.1. of the article for description of the derivation of
intensities. Summary: the 2.2 m telescope was used as monitoring
telescope, and its values are used directly.
An abrupt change in the intensities during a night indicates a CHANGE
OF TARGET; these are readily seen from Fig. 3. of the article.
=> The unit "S_10" (tenth magnitude stars per square degree) corresponds
to the surface brightness which produces per square degree the flux
of a 10th-magnitude star in the observed wavelength range.
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Byte-by-byte Description of file: table3c
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Bytes Format Units Label Explanations
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3- 8 I6 "DD/MM/YY" Date Date
12- 18 F7.4 h End End of Twilight (LST)
21- 27 F7.4 h Beg Beginning of Twilight (LST)
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(End) Simona Mei [CDS] 13-Mar-1995