Figure 4 : Gemini-South low-resolution spectra for three BLAPs.

From: Blue large-amplitude pulsators as a new class of variable stars

Figure 4

In the segments, small ticks are every 10 Å. Best fits of stellar atmosphere models are shown with red lines. The sodium doublet (Na i D) is of interstellar origin. The uncertainties are formal errors returned by the χ2 fitting procedure. Effective temperatures, surface gravities, and helium abundances derived for these stars are similar to the values obtained from moderate-resolution spectra for the prototype object OGLE-BLAP-001. This shows that all of the newly discovered variables form a homogeneous class of objects.