TESS survey of rotational and pulsational variability of mercury-manganese stars
| Autor: | A. David-Uraz, Ernst Paunzen, Viktor Khalack, Oleh Kobzar, Coralie Neiner, Oleg Kochukhov, J. Labadie-Bartz |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
oscillations [stars]
Rotation period close [binaries] Period (periodic table) FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences early-type [stars] chemically peculiar [stars] Astronomi astrofysik och kosmologi 0103 physical sciences Astronomy Astrophysics and Cosmology Astrophysics::Solar and Stellar Astrophysics Variation (astronomy) 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics 010308 nuclear & particles physics Starspot Astronomy and Astrophysics Light curve Magnetic field starspots Stars Amplitude Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science rotation [stars] Astrophysics::Earth and Planetary Astrophysics |
| Popis: | Mercury-manganese (HgMn) stars are late-B upper main sequence chemically peculiar stars distinguished by large overabundances of heavy elements, slow rotation, and frequent membership in close binary systems. These stars lack strong magnetic fields typical of magnetic Bp stars but occasionally exhibit non-uniform surface distributions of chemical elements. The physical origin and the extent of this spot formation phenomenon remains unknown. Here we use 2-min cadence light curves of 64 HgMn stars observed by the TESS satellite during the first two years of its operation to investigate the incidence of rotational modulation and pulsations among HgMn stars. We found rotational variability with amplitudes of 0.1-3 mmag in 84 per cent of the targets, indicating ubiquitous presence of starspots on HgMn-star surfaces. Rotational period measurements reveal six fast-rotating stars with periods below 1.2 d, including one ultra-fast rotator (HD 14228) with a 0.34 d period. We also identify several HgMn stars showing multi-periodic g-mode pulsations, tidally induced variation and eclipses in binary systems. 18 pages, 7 figures; accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|