Last Be spectrum

Last spectra of Be stars after two weeks of bad weather. Some different aspect of the Ha line profile depending of the Be activity and sight of view, pole on or equator.

Gam Cas,mV 2.39 B0IVpe

HD57682, mV 6.4 O9Ve,

HD70340, mV 6.4 A2Vnnpe

HD112028, mV 5.3 A1IIIshe

HD142926, mv 5.74 B9pe

Most of the spectrum are made in binnig2X2. Only the bright gam cas was made in binning 1X1 mode. The dispersion is twice in Bin2 than in Bin1 for the same resolution, around 15000 here.

Slit is 35µm large and ccd pixel are 6,4µm.

SNR for gam cas is 106 (good for astrophysics reduction), 20 for HD70340 (enough to detect outburst).

It depends of the V mag, altitude, activity, star neighborhood and spectral type. Note the intensity scale is not the same.