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Article
Open AccessNear-infrared sky background fluctuations at mid- and low latitudes
The emission of the upper atmosphere introduces an additional variable component into observations of astronomical objects in the NIR 700–3,000 nm range. The subtraction of this component is not easy because i...
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Article
Jets And Arcs In The Coma Of Comet Hale-Bopp From August 1996 To April 1997
An observation program for measuring the activity of Comet Hale-Bopp was conducted at the Observatoire de Haute Provence from August 1996 to April 1997. Narrow band images were obtained from the 120 cm telesco...
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Chapter and Conference Paper
Spectroscopic Evidence of Organic Molecules Released by the Dust of Halley’s Inner Coma
New spectroscopic arguments supporting the probable presence of organic molecules in the material released by comet Halley are deduced from the data obtained by the Vega three-channel spectrometer. Two excesse...
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Chapter and Conference Paper
Spatial Distribution and Color of Dust in Halley’s Inner Coma
Composite images of the intensity of solar radiation scattered by dust in Halley’s coma are constructed by using the three-channel spectra obtained during the approach phase of the Vega 2 spacecraft They cover...
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Chapter and Conference Paper
Properties of dust in comet P/Halley measured by the Vega-2 three-channel spectrometer
Optical properties of cometary dust exhibit no substantial variations at distances from 100 to 15 000 km from the nucleus. Dust ejection can be approximated by cos φ where φ is the angle with the sun-nucleus axis...
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Chapter and Conference Paper
Spectrophotometry of comet P/Halley at wavelengths 275—710 nm from Vega 2
Spectrophotometric observations of the inner coma of comet Halley in the range 275-710 nm were conducted from Vega 2 on March 8, 9, 10, 11, 1986. During the encounter session, when the impact parameter was min...
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Article
Corrigendum: Near-ultraviolet and visible spectrophotometry of comet Halley from Vega 2
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Article
Spectroscopic study of comet Halley by the Vega 2 three-channel spectrometer
The three-channel spectrometer (TKS) aboard the Vega 2 spacecraft recorded infrared and visible spectra near the nucleus of comet Halley. Spectra in the range 0.95–1.9 µm at a distance of 300 km from the nucle...
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Article
Near-ultraviolet and visible spectrophotometry of comet Halley from Vega 2
We report results obtained by the near-ultraviolet and visible channel (V) of the TKS instrument1 carried by Vega 2 during the hour preceding its closest approach to comet Halley. The brightness of the OH (0, 0) ...
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Chapter and Conference Paper
Infrared Observation of Non Thermal Emissions from Spacelab
Observations of the emissions of atmospheric ozone and nitric acid in the 10 μm window have already been used for the monitoring of these constituents in the stratosphere. We propose to generalise these method...