We reported the results of observations of small-scale variability in the hydrogen Balmer lines in Vega. Spectral observations were carried out with low-resolution spectrograph (R ≃ 600) installed in the Main Astronomical Observatory, Ukraine. Spectra were obtained with a time resolution in the second range. It has been found that Vega shows variations in the hydrogen lines Hβ, Hγ, Hδ. This can be interpreted that their variations are non-radial pulsations. The characteristic time of the observed variations ranges from 300 to 1200 sec. The horizontal scale for oscillating elements is about 800 Mm, which is comparable to the solar radius. The radial velocity of the variations is about 36 km/s.
“Kinematics and Physics of Celestial Bodies” is (or has been) a significant journal coming from Ukraine. However, the results these folks give can’t be correct. At spectral resolution R = 600 you won’t see rv variations reliably unless they are quite large, and the claimed changes of 36 km/sec would have been noticed long ago. There are very small variations in rv and in Vega, but down at the millimag level photometrically.
With good technique, detecting 36 km/s pp RV variations is feasible at R~600, for example here to ~5km/s 1 sigma precision at R~1000 in David Boyd’s “Observing with a LISA” presentation, slides 43-52 https://britastro.org/document_folder/baa-document-store/past-talks/spectroscopy-workshop-at-the-nlo-oct-2015
but yes the claim of 300sec RV pulsations of Vega at 36km/s in this paper are clearly not present. For example I followed Vega for several months back in 2014 using it as an RV reference as part of this investigation in to the RV variations of Deneb. Starting at 18:35 min https://britastro.org/videos/pushing-the-limits-using-commercial-spectrographs-2
Each RV point is an average of typically 10 x30sec exposures at R~15000 measuring a pair of Si lines so the individual exposures should have easily shown any variation of this magnitude (The shifts would be greater than the line width) but checking back I see no variation in individual exposures above the 0.5km/s precision of the measurement.