Velocidades radiales con el espectrógrafo REOSC del CASLEO en dispersión simple

CELLONE, S. A.

San Juan

Congreso; 41a. Reunión Anual AAA; 1997

AAA

Test spectra obtained with the CASLEO 2.15 m telescope + the REOSCspectrograph in its simple--dispersion configuration are analized. Thesame star was placed at different positions along a 6 arc--min longslit; it is shown that the measured radial velocity varies very stronglywith the position along the slit. The maximum variation ammounts toseveral hundreds of km/s. On the other hand, radial velocities measuredfrom the Halpha and from the Hbeta lines donot give the same result, again differing by several hundreds of km/s.These results show that the REOSC spectrograph produces completelyunreliable radial velocities in its simple--dispersion configuration,and should not be used with this purpose.