The only spectra of BD +55 521 currently in the ARAS BeAm database date from January
2003, so an update is overdue. Two low resolution spectra were
measured on 20th and 22nd September 2008 using the Star Analyser grating.
While not showing the detailed line profile, it should be possible to
estimate if the strength of the H alpha emission line has
changed significantly.
The Star Analyser spectra were
reduced in the usual way and finally normalised using a fit to the
continuum. The 2003 spectrum from the OHP ELODIE database was
normalised in the same way and Gausian filtered to match the Star Analyser
resolution for comparison.
At high resolution, the 2003 ELODIE spectrum
shows emission features in the H alpha line (see below). When
filtered to simulate the resolution of the Star Analyser spectrum
however, the net effect is of a slight overal absorption centred at the H alpha
wavelength. By contrast, the two Star Analyser spectra recorded in
September 2008 show a distinct emission feature at this position. This suggests
that there may have been a significant increase in the strength of H alpha
emission in this star since 2003. A higher resolution spectra would be required
to investigate the detailed nature of the change but the star is too faint to
measure this using the Three Hills Observatory LHIRES III
spectrograph.
A high resolution plot of
the H alpha region from the 2003 spectrum in the ELODIE Archive
