The presented ORFEUSII Echelle spectrum of HD93521 shows an
extraordinary rich variety of very sharp interstellar absorption lines,
especially in the wavelength region between 900Å and 1200Å,
which was not very well studied before the two ORFEUS missions
and for which only now new observation possibilities exist.
Particularly the nearly complete presence of very sharp (FWHM 100mÅ) H2 absorption lines in this spectrum - which will be
analysed in detail in a forthcoming paper - makes it well suited as a
reference spectrum for interstellar molecular hydrogen. Molecular
hydrogen is partially visible in the interstellar high velocity
component too. Additionally some stellar lines show narrow absorption
components wich are varying in time and which could be an indication
for a disk.
Acknowledgements
ORFEUS could only be realized with the support of all our German and American colleagues and collaborators. The authors wish to thank Philipp Richter and Klaas S. de Boer for helpful discussions. The ORFEUS program was supported by DARA grants WE3OS8501 and WE2QV9304 and NASA grant NAG5-696.
Copyright The European Southern Observatory (ESO)