the discovery of cool material around main-sequence stars such as vega and beta pictoris has been the most impacting discovery of the iras mission, and is widely seen as one of the most promising new facts that may lead to a better understanding of the formation of planetary systems. ground based measurements have provided a first hint that cometary-like silicate surrounds beta pic. with iso-sws, this feature can be studied much more accurately and has been detected in other stars as well, such as hd 100546. for these reasons, an sws aot6 measurement covering the full sws wavelength range was done as part of the cwaelken.crystal programme. however, the noise in this observation was much higher than expected because of the presence of an unusual high number of so-called .single detector jumps. as described in the sws idum. in the 7-12um region, the most important region to quantify the physical conditions, shapes and abundances of the different crystalline dust components, there is not one among all 12 detectors that doesn.t show this kind of jump in both up- and downscan. because of the unusual high single detector jump rate, the old observation is currently under investigation by the sws instrument dedicated team at vilspa. more specifically, a possible connection with the solar flare event three revolutions before the observation (rev 725) is being looked at. although the direct impact of the solar flare event on the detectors (higher dark current, higher dark noise) is not visible one revolution after the solar flare event, the unusual high number of detector jumps might be related to discharges in the instrument after the whole satellite was charged heavily by the solar flare event. the present spectrum allows us to conclude that several features due to crystalline silicates, and maybe h2o-ice, are present in beta pictoris, but will not be sufficient for a quantitative description of the composition of the dust in the debris disk. because of the fundamental importance of the object, we propose to reobserve beta pictoris in certain critical bands, using an strategy that is less affected by possible instrumental effects.
Instrument
SWS06
Temporal Coverage
1998-04-01T18:19:18Z/1998-04-01T20:45:54Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, WAELKENS et al., 1999, 'CIRCUMSTELLAR CHEMISTRY OF THE MAIN SEQUENCE STAR BETA PICTORIS', 1.0, European Space Agency, https://doi.org/10.5270/esa-01s0pz4
