Edition 14 of the Astronomy On-line Newspaper

Letter from La Silla

La Silla Observatory, 20 November - 22:30 UT

The conditions last night (November 19 - 20) at the La Silla observatory were very good for astronomical observations. In addition to clear skies, we experienced good `seeing', allowing us to resolve more detail and observe fainter stars.

The waxing moon is almost full, and so the sky was `bright' for most of the night. As the Astronomy On-line proposals generally called for observations of brighter objects, the sky brightness was not a serious impedement.

The 91-cm Dutch telescope was kept busy the whole night observing for the Astronomy On-line proposals. An early attempt was made to observe comet Hale-Bopp. Unfortunately this comet is now too low in the sky for the Dutch telescope to observe (professional telescopes are generally not designed to observe objects low down on the horizon). This aside, many other interesting observations were made. These included Saturn, three asteroids, a globular cluster, an open cluster, a binary star system, a supernovae, and the Jewel Box cluster. Sample images can be found on the Astronomy On-line pages, see for instance the article in Newspaper no. 13.

The conditions for the second night of the observations is looking good. To the east of the observatory are the Andes, and currently a few large thunder clouds can be seen in that direction. This is a seasonal effect known as a `Bolivian winter' and should not hamper tonights observations. Looking to the horizon it appears quite hazy, indicating that the humidity is quite high. Again, we do not expect this to pose a serious threat to tonights observations. Tonight we are hoping to complete some of the projects from last night which require temporal coverage, as well as making observations for other AOL projects. If all goes well, sample images will be placed on the web tomorrow morning (Chilean time!).

La Silla Observatory, 21 November - 09:30 UT

The conditions at La Silla were good this night (November 20 - 21); we had clear skies throughout the night as well as good `seeing'.

Some technical difficulties with the Dutch telescope were experienced: the telescope control system (TCS) crashed once, while the computer controlling the CCD crashed twice. However, these hardware malfunctions had an insignificant impact on the observations.

A brief outline of the observations secured at the Dutch telescope this last night will be published in a few hours in the Newspaper.

James Brewer
Astronomer (ESO-Chile)

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Last update: Nov 21, 1996