  During intensive/comparative studies with Preston's spectroscopic works
(1961, 1962, 1964 & 1965) on RR Lyrae atmospheric phenomena, I unexpectedly
found the existence of hypersonic shock waves (Chadid 1996 & 2008), that are
strongly connected with the turbulence amplification mechanism (Chadid 1996b)
and the Blazhko modulation (1997). Here I will show how the hypersonic shocks
are at the origin of helium line formation and connected with the helium
emission and line doubling detected by Preston (2009, 2011).
  I will present new neutral and single ionized helium line data in the
hypersonic Blazhko star S Arae. The He II appears as a weak emission and its
origin is strongly connected with the hypersonic shock in S Arae. The shock is
extremely strong and can reach a Mach number >30. The HeI lines first appear in
emission, over ~2% of the pulsation period, followed by the HeI absorption
doubling phenomenon occurring simultaneously with the neutral metallic
absorption line phenomenon over ~8% of the pulsation period.
  Despite several claimed detections of magnetic fields in RR Lyrae, Preston
(1967) found none after two years of observations. This is consistent with my
recent spectro-polarimetric measurements (2004), over four years, concluding
that RR Lyr is a bona fide nonmagnetic star, leading to the falsification of
all the models of the Blazhko effect requiring strong photospheric magnetic
fields. I report on a new series of high precision circular polarization
spectroscopic observations of Blazhko star RV UMa. The longitudinal field
measurements of RV UMa show a mean longitudinal magnetic field of B_l =
-13+/-35 G, and no significant detection over the entire pulsation cycle.
  These spectroscopic results reveal a serious challenge for explaining the
complex behavior in the pulsation of hypersonic atmospheres of RR Lyrae stars.
