First Astronomical Light with TIMMI2, ESO's 2nd-Generation Thermal Infrared Multimode Instrument at the La Silla 3.6-m Telescope
TIMMI, featuring a 64 × 64 gallium doped silicon array and mostly ger-manium refractive optics inside a solid-nitrogen/liquid-helium dewar, was in constant use until its decommission-ing in 1999 (cf. Stecklum et al. 1999). By then, the development of detectors had progressed so rapidly, that the instrument no longer appeared competitive. In fact, in 1993 ESO joined a consortium of French institutes to develop, based on the array used e.g. in TIMMI, a next-generation device (cf. e.g. Lucas et al. 1994). Already the format of this device (128 × 192 pixel) suggested that it would be desirable to build a new camera, rather than trying to use the new device in the existing setup. Even larger arrays were announced by US suppliers. To that end ESO had developed some basic ideas for the optics of a next-generation instrument for the La Silla 3.6-m telescope (cf. Käufl & De-labre, 1994). As a result of the La Silla 2000 questionnaire (see Anderson 1994) in The Messenger 78, ESO received a proposal from the A s t r o p h y s i k a l i s c h e s Institut und Sternwarte of the Friedrich-S c h i l l e r-Universität (FSU) in Jena, Germany, to build TIMMI2. This proposal , reflecting ESO's optical concept, was based on a modern cryostat cooled by a Closed Cycle Expansion Cooler Machine and was also featuring a polarimetric option (not available in TIMMI). Personnel cost and capital investments could largely be covered by funds raised by the Institute in Jena. The PI in Jena was Hans-Georg Reimann. After some negotiations , a Memorandum of Understanding was signed and the work began in early 1996. The design sketch of ESO (see above) was first transformed into a FEM 1 certified conceptual design, both for the optics and mechanics, by the company Jena-Optronik GmbH. Based on this work, the final design and the detail design of the instrument were done at the physics department of the FSU. To the extent that this was feasible, all mechanical parts were manufactured in the workshops of the FSU. In the course of the project, the group at the FSU could enlist a team from the Sternwarte der Universität Wien f o r
The evolution of V4334 Sgr (Sakurai's object) in the Mid-Infrared
Since Sakurai's object (V4334 Sgr) underwent a late helium flash in 1995, its fast evolution has been monitored with great eort. We present TIMMI and TIMMI 2 photometric observations covering a spectral range from 5 to 20m with a total of 8 filters. We found drastic changes in the spectral energy distribution indicating a drop of temperature in the dust envelope from 1000 to 600 K in half a year only. Combined with optical observations reported elsewhere, we conclude that the phase of dust formation has probably stopped in mid-2001 and that the dusty envelope has been expanding only, ever since. An expansion velocity of about 1000 km s 1 is required to explain the rapid cooling. Other optical and near-infrared observations support the existence of such high velocity flows in the envelope of V4334 Sgr. An estimate for the bolometric luminosity of 2000 L is derived for a distance of 1 kpc. Taking into account theoretical models a distance of 2 1 kpc to V4334 Sgr is suggested. As a consequence of its fast final helium flash evolution, Sakurai's object may start to destroy its surrounding dust in the not too distant future.
Nietzsche's Moral Philosophy
Expounds and criticizes the moral consequences of Nietzsche's basic concept of the will to power. This study argues that Nietzsche's doctrines on moral subjects reveal a man profoundly torn between different and conflicting impulses.