aat Acta Astrophys. Tau. Acta Astrophysica Taurica 2712-925X Kiselev Nikolai Nikolaevich, Mosсow, settlement Moskovskii, Tat'yanin Park Str., 12, Moscow, Russia. RU 122 TVQWNZ Instruments and Methods Compensation for low-frequency and quasistatic aberrations in stellar spectroscopy Emelianov Eduard Yushkin Maksim Verich Yurii Panchuk Vladimir Special Astrophysical Observatory of the Russian Academy of Sciences, Nizhnij Arkhyz 369167, Zelenchukskiy region, Karachai-Cherkessian Republic, Russia Special Astrophysical Observatory of the Russian Academy of Sciences, Nizhnij Arkhyz 369167, Zelenchukskiy region, Karachai-Cherkessian Republic, Russia Special Astrophysical Observatory of the Russian Academy of Sciences, Nizhnij Arkhyz 369167, Zelenchukskiy region, Karachai-Cherkessian Republic, Russia Special Astrophysical Observatory of the Russian Academy of Sciences, Nizhnij Arkhyz 369167, Zelenchukskiy region, Karachai-Cherkessian Republic, Russia 31 03 2026 7 1 4 7 12 03 2026 Copyright (c) 2026 Eduard Emelianov, Maksim Yushkin, Yurii Verich, Vladimir Panchuk 2026 Eduard Emelianov, Maksim Yushkin, Yurii Verich, Vladimir Panchuk The metadata for this submission is licensed under a Creative Commons Attribution 4.0 International License. Copyright and publishing rights for texts published in Acta Astrophysica Taurica is retained by the authors, with first publication rights granted to the journal.Texts are free to use with proper attribution and link to the licensing (Creative Commons Attribution 4.0 International).

We report methods for correcting low-frequency variations in the position of the star image at the input of the spectral equipment at the BTA Nasmyth and primary foci, used for the past two decades at the telescope. New technical solutions make it possible to extend the operating frequency range to 6 Hz for stars brighter than 10 m .

spectral instrumentation aberration correction Observations at the 6-meter telescope of the SAO RAS are supported by the Ministry of Science and Higher Education of the Russian Federation. Financial support was provided by grant No. 075-15-2022-262 “Multi- wavelength study of nonstationary processes in the Universe” (13.MNPMU.21.0003) Emelianov E.V., 2015. Astrophys. Bull., vol. 70, iss. 3, pp. 362–370. Ivanov A.A., Panchuk V.E., Shergin V.S., 2001. SAO RAS preprint No 155, pp. 1–19. (In Russ.) Klochkova V.G., Sheldakova Yu.V., Vlasyuk V.V., Kudryashov A.V., 2020. Astrophys. Bull., vol. 75, iss. 4, pp. 468–481. Panchuk V.E., Chuntonov G.A., Naidenov I.D., 2014. Astrophys. Bull., vol. 6, iss. 3, pp. 339–355. Panchuk V.E., Klochkova V.G., Yushkin M.V., 2017. Astron. Rep., vol. 61, iss. 9, pp. 820–831. Tamarov V.A., Tavolzhanskaya A.S., Panchuk V.E., 2022. XI All-Russian conference "System synthesis and applied synergetics". Rostov-on-Don – Taganrog: South Federal University Publishing House, pp. 279–281. (In Russ.)