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ISO SWS Spectroscopy of Proto-Planetary Nebulae

Volk, Kevin; Kwok, Sun; Hrivnak, Bruce J.

We are obtaining low- (SWS01) and medium-resolution (SWS06) spectra of PPNe to investigate spectral features arising in these transitional objects. Three sources with the 21 µm feature have been confirmed, one new source found, and evidence of some substructure seen.

Observation of Microstructures in Planetary Nebulae

Walsh, J. R.; Dudziak, G.

HST images of 5 Planetary nebulae showing small scale structures have been retrieved from the archives. For two PNe, NTT images were also available, and a double channel deconvolution technique applied to combine them to the HST images. A very precise flux calibration was performed on the HST images. Bow shocks and ionization effects are likely de…

Infrared Emissions from Metals in Carbon Stars and M Giant

Ohnaka, K.; Tsuji, T.; Aoki, W.

Determination of highly accurate proper motions for 32 Hipparcos stars from photographic plates.

Wang, S.; Wang, J.; Jin, W. +1 more

The authors have reduced 70 exposures on 32 photographic plates taken in four sky areas around the radio source 0316+413, the galaxy NGC 7302, the Pleiades astrometric standard region, and some other objects. The plates were obtained with the 40-cm astrographic refractor at the SheShan(Zô-Sé) station of the Shanghai Observatory. Using the PPM cata…

Dust and Atomic Gas in Post-AGB Envelopes

Meixner, M.

Atmospheric studies with spectro-imaging : prospects for the vims experiment on Cassini

Bellucci, Giancarlo; Bellini, Barbara; Formisano, Vittoria

Spectroscopic observations of Jupiter and Saturn are here reported to show the possible applications to the future data acquired by the instrument VIMS ( Visible and Infrared Mapping Spectrometer) on board of the Cassini Mission. The following images and spectra have been acquired by a similar instrument called VNIR ( Visible and Near Infrared Spe…

V 439 CYG as a Late Phase of Stellar Evolution

Rossi, C.; Viotti, R.; Norci, L. +2 more

Rapid continuum variability in NGC 4151

Crenshaw, D. M.; Malkan, M.; Warwick, R. +4 more

Intensive monitoring of NGC 4151 showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in ~1.5 keV X-rays, with weaker variations at ~100 keV and no significant variability in the 0.1-1 keV bands. In the ultraviolet/optical regime, the fractional variability amplitude decreased fro…

Obscured AGB Stars in the LMC

Waters, L. B. F. M.; Whitelock, Patricia A.; Groenewegen, M. A. T. +5 more

HI Infrared Line Formation in Early B-Type Stars

Waters, L. B. F. M.; Marlborough, J. M.; Zaal, P. A.