Edition 13 of the Astronomy On-line Newspaper

Report about the Observations

Last night (19/20 November) observations were attempted at the participating observatories. The weather was poor across Europe and many places had to stay closed. We hope for better observing for tonight! The risk of cloudy nights is part of the life of astronomers. The Dutch telescope on La Silla has had a very productive night.

Several groups have requested observations of bright stars. This can be a problem for CCDs which saturate easily. Where possible, these observations were done with a neutral-density filter (ND) to decrease the observed intensity.

The following reports have already been received:

Portugal (COAA)

Unfortunately we only managed two observations last night (19/20) which were: cloud cover (8/8) and rainfall (3 mm).. We will try tonight - the forecast is slightly more favourable.

Denmark (Brorfelde)

Nearly clear sky for a very short time,- and weather forecast now says more clouds and later in the night rain!! Only a few dome flats and dark exposures done. If observations become possible tomorrow, images can be downloaded from

http://www.astro.ku.dk/astronomyonline/aoldk/images/

Slovenia (Crni Vrh) P7, P11, P16, P21, P26)

A short brake in clouds that suddenly appeared early this evening enabled us to do the first batch of AOL observing projects. Due to the lack of time it was not possible to assemble all instrumentation as we initially expected. Both comet Hale-Bopp and Moon images were therefore taken with the same instrument (36-cm, f/6.8 S-C) and appropriate filters. Anyway, we believe the data we obtained will be useful. We'll repeat these observations according to group proposals in case the weather recovers. Full information is available at:

http://www.fiz.uni-lj.si/astro/comets/aol/propos.html

The data files can be downloaded from this location.

ESO/Chile (La Silla, Dutch 90cm)

Good weather. Sample files have been put on the Web page (http://epu.ls.eso.org/lasilla/Telescopes/2p2T/aol/data.html). Due to constraints on disk space all of the images acquired at the Dutch telescope will not be immediately available. However, there is at least one image from each proposal. Details on obtaining the full data set will become available soon.

-P8: Binary Star System 66 Cet. This binary system is well placed for observation from the southern hemisphere. I have UBVR images of the system using a ND2 filter. I also have ND2 flat fields in UBVR, and images of the standard star E2-C in UBVR with ND2. As I observed only one standard star, no colour term can be derived though a reasonable calibration of the data should be possible.

-P9: Distance to asteroids. From UT 1:53 to UT 2:17 I observed the three asteroids sequentially. I obtained 5 images of each asteroid spaced over this period. All the images are in R. I re-observed all three asteroids at around UT 5h30m -- their motions were easily detected. Indeed, I had to move the telescope to recover Semiramis!

-P13: B and V photometry in NGC 362. I obtained 3x420s in B, 3x300s in V, 3x40 in B, and 3x30 in V under good seeing conditions (~1.2 -- not bad for the Dutch!). Additionally, two fields in PG231 were observed and 5 standard stars are in these fields. Single B and V (both long and short) observations of the field in NGC362 were made again at LT=2:00 and 3:20 (The original observations were made at LT=23:45). Flat fields and a bias frame are available for these data.

-P15: Atmosperic absorption. I observed a field in the Pleiades at zenith distance of 73 degrees with BVR filters, and again at ZD=53 (transiting meridian). The PG231 standards can be used to calibrate these data. Flat fields and a bias frame are available for these data. I note that the observations of NGC 362 might also be useful to this group.

-P17: Saturn. Using the ND2 filter I obtained 3x5s and 3x1s images of Saturn. These images (more so the 1 sec ones) look great. These images were taken with a V filter, and I have the frames needed to make a ND2 V flat field.

-P21: Investigation of Hale Bopp. Unfortunately this is below the ZD limit for the Dutch even very early in the evening. No observations possible. -P23: SNe in NGC 673. This was in fact observed by Turatto and Bennetti the night before the AOL observations. They have kindly made their data available to the AOL observers. UBVRI photometry has been secured, though no H-alpha images as this is a type Ia SN! Flat fields, a bias frame, and standards are available for these data.

-P25: The Jewel Box. I observed this in B (6x75), V (6x20) and R (6x5) using a ND2 filter. I had already secured ND2 flat fields in BVR, as well as observing the standard star E2-C.

Other observatories

No reports have yet been received from the other observatories. We expect that most places will have had poor weather.

Albert Zijlstra
Coordinator (ESO)


Astronomy On-line | EAAE | ESO | Help | Search
Last update: Nov 20, 1996