000007770 001__ 7770
000007770 005__ 20260108161002.0
000007770 0247_ $$2DOI$$a10.1093/mnras/staf1247
000007770 037__ $$aSCART-2026-0040
000007770 100__ $$aDileep, Athul
000007770 245__ $$aChemical abundances and Doppler imaging of the Ap Si/He-wk star HD 100357
000007770 260__ $$c2025
000007770 520__ $$aWe present the results of time-resolved photometry, abundance analysis, and Doppler imaging of an Ap star, HD 100357. The TESS photometry revealed rotational modulation with a period of 1.6279247 d. Upon inspecting the residuals after removing the rotational period and its harmonics, we found additional frequencies around 15.8054 d⁻1, which we later confirmed with ground-based observations as originating from a nearby star. Using high-resolution spectroscopy, we identified HD 100357 as an Ap Si/He-wk star exhibiting rotational modulation caused by surface abundance spots. The stellar parameters of HD 100357 were determined as T_eff = 11 850 K, logg = 4.57, υsini = 60 kms^{-1}, and an inclination angle i = 72 deg. The detailed abundance analysis revealed strongly overabundant stratified silicon, an overabundance of iron-peak elements and rare earth elements combined with remarkably deficient helium. Mapping of Fe and Cr abundances revealed the existence of ring-shaped regions with a lower concentration of the elements. Their geometry might reflect the orientation of the hypothetical magnetic field of the star, oriented ∼90 deg to the rotational axis. HD 100357, with its strong chemical peculiarities and indications of possible magnetic fields, represents an interesting candidate for follow-up spectropolarimetric observations aimed at investigating its magnetic field topology and stellar activity.
000007770 594__ $$aNO
000007770 6531_ $$aLine: profiles
000007770 6531_ $$aStars: abundances
000007770 6531_ $$aStars: chemically peculiar
000007770 6531_ $$aStars: individual: HD100357
000007770 6531_ $$aStars: rotation
000007770 6531_ $$aStars: starspots
000007770 6531_ $$aSolar and Stellar Astrophysics
000007770 700__ $$aJoshi, Santosh
000007770 700__ $$aAlexeeva, Sofya
000007770 700__ $$aKochukhov, Oleg
000007770 700__ $$aSemenko, Eugene
000007770 700__ $$aDe Cat, Peter
000007770 700__ $$aZúñiga-Fernández, Sebastián
000007770 700__ $$aTrust, Otto
000007770 700__ $$aPollard, Karen
000007770 700__ $$aCrause, Lisa
000007770 700__ $$aBarkaoui, Khalid
000007770 700__ $$aGillon, Michaël
000007770 700__ $$aJehin, Emmanuel
000007770 700__ $$aRathore, Neeraj
000007770 773__ $$c747--761$$n2$$pMonthly Notices of the Royal Astronomical Society$$v542$$y2025
000007770 8560_ $$fpeter.decat@ksb-orb.be
000007770 8564_ $$s4163602$$uhttps://publi2-as.oma.be/record/7770/files/Dileep2025_MNRAS542_747.pdf
000007770 8564_ $$s4337$$uhttps://publi2-as.oma.be/record/7770/files/Dileep2025_MNRAS542_747.gif?subformat=icon$$xicon
000007770 8564_ $$s6774$$uhttps://publi2-as.oma.be/record/7770/files/Dileep2025_MNRAS542_747.jpg?subformat=icon-180$$xicon-180
000007770 905__ $$apublished in
000007770 980__ $$aREFERD