eso9207 — Comunicado científico
Comet Halley 1992
13 de Mayo de 1992
This negative photo shows a small sky area in the direction of Comet Halley, obtained by ESO astronomers Alain Smette and Olivier Hainaut with the ESO 3.5-metre New Technology Telescope (NTT) in the morning of April 6, 1992
It is a composite of 10 individual exposures in the standard V-band, obtained between UT 2:33 and 4:58 with a total integration time of 2 hours. They were combined in such a way that the image of the moving comet remains at the same position; this is why the stars are seen as trails. The position of Comet Halley is indicated, about only 2 arcminutes North-West of a bright (magnitude 7) galactic star whose strong light is seen at the lower right in the photo.
At the time of the observations, Comet Halley was 2343 million from the Earth and 2424 million km from the Sun. The predicted magnitude of the nucleus alone is V = 25.95. The very faint image of Halley is near the limit of the exposures and the observed magnitude is fainter than 25.5, possibly close to 26.
This observation therefore shows that the large dust cloud which was ejected during a dramatic eruption in late December 1990 and first observed at La Silla in mid-February 1991, has now disappeared. At the present time, 16 1/2 months after the outburst, there is very little, if any dust left near the nucleus.
The photo covers an area of 105 x 140 arcseconds; North is up and East is to the right.