Chemically peculiar stars as seen with 2MASS

Herdin, Andreas; Paunzen, E.; Netopil, M.

doi:10.1051/0004-6361/201527390

Cited by 7 publications

(3 citation statements)

References 33 publications

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“…This procedure resulted in 10 200(300) K, which is in line with the former value. As last test, we applied the temperature calibration using (V − K s ) 0 , which was especially derived for CP stars (Herdin et al 2016), and yielded 10900(500) K. Again, this is in line with all other values, which provides confidence in this astrophysical parameter.…”

Section: Estimation Of Reddening and Stellar Parameterssupporting

confidence: 67%

HD 240121 - An ACV variable showing anti-phase variations of the B and V light curves

et al. 2017

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The variability of HD 240121 = BD+59 2602 was first suspected by Särg & Wramdemark (1970) and later confirmed by Gröbel (1992a,b). Because of the observed anti-phase variations of the B and V light curves, the latter author tentatively suggested an ACV type. Apart from its inclusion in the catalog of New Suspected Variables (NSV 25977), no further investigations of the star have been published. HD 240121 was included into our target list of ACV candidates and investigated in order to determine the reason for the observed brightness variations. All available information on HD 240121 were collected via an exhaustive data mining procedure. Data from Gröbel (1992a,b) were re-analysed and photometric observations from the NSVS and Hipparcos archives were procured and investigated. Line-of-sight reddening and stellar parameters were calculated from archival photometric data. HD 240121 is a young, late B-type CP2 star of the silicon subgroup. The observed period, amplitude of light variations and variability pattern (anti-phase variations) are typical of ACV variables. The occurrence of anti-phase variations of the B and V light curves is rarely observed and points to the existence of a null wavelength in the visual spectrum. We therefore strongly encourage further multi-colour photometric observations of this star.

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Section: Estimation Of Reddening and Stellar Parameterssupporting

confidence: 67%

HD 240121 - An ACV variable showing anti-phase variations of the B and V light curves

et al. 2017

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“…The difference in T eff could be introduced by the assumption that (V -K) and (B -V) are completely log g and metallicity independent (Ramírez & Meléndez 2005). Some of the target stars in the sample are chemically peculiar and/or variable, which may introduce additional errors in the calibration process (Herdin et al 2016).…”

Section: Atmospheric Parameters From Photometrymentioning

confidence: 99%

HERMES spectroscopy of normal A and Am stars

Trust,

Jurua,

De Cat

et al. 2021

Preprint

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The nominal Kepler mission provided very high-precision photometric data. Using these data, interesting phenomena such as spots, and "hump and spike" features were observed in the light curves of some normal A and metallic lined A stars (Am stars). However, the connection between such phenomena and the chemical peculiarity of the Am stars is still unclear. In order to make progress on these issues, its important to collect high-resolution spectroscopic data to determine their fundamental parameters and individual chemical abundances. In this paper, we present a spectroscopic study of a sample of "hump and spike" stars in the nominal Kepler field. We used data collected with the High Efficiency and Resolution Mercator Échelle Spectrograph (HERMES). We determined the spectral type of these stars and obtained the atmospheric stellar parameters such as effective temperatures, surface gravities, projected rotational, microturbulent and radial velocities. We also performed a detailed individual chemical abundance analysis for each target. We confirmed KIC 3459226 and KIC 6266219 as Am stars, KIC 9349245 as a marginal Am star, while KIC 4567097, KIC 4818496, KIC 5524045, KIC 5650229, KIC 7667560, and KIC 9272082 are non-Am stars. To estimate their evolutionary phases, all the stars were placed in the Hertzsprung-Russell (HR) diagram. Based on their spectral classification and chemical abundance pattern, we reclassified KIC 6266219 (previously treated as chemically normal) as an Am star (kA3hA7mF1) and KIC 9272082 (previously treated as Am) as non-Am.

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“…The origin of this circumstellar material is still unknown. Herdin et al (2016) and Chen et al (2017) investigated the group of CP stars in the infrared region using 2MASS, IRAS, and WISE data. The latter summarized their result as follows.…”

Section: Analysis Of the Spectral Energy Distributionmentioning

confidence: 99%

A Binary Nature of the Marginal CP Star Sigma Sculptoris

Janík¹,

Krtička²,

Mikulášek³

et al. 2018

PASP

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The A2 V star σ Scl was suspected to be a low-amplitude periodic variable of the Ap type by several authors. Aiming at deciding whether the star is a variable chemically peculiar (CP) star, we searched for the photometric and spectroscopic variability and determined chemical abundances of σ Scl. The possible variability was tested using several types of periodograms applied to the photometry from Long-Term Photometry of Variables project (LTPV) and Hipparcos. Sixty spectrograms of high quality were obtained and used for chemical analysis of the stellar atmosphere and for looking for spectral variability that is symptomatic for the CP stars. We neither find any signs of the light

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Chemically peculiar stars as seen with 2MASS

Cited by 7 publications

References 33 publications

HD 240121 - An ACV variable showing anti-phase variations of the B and V light curves

HD 240121 - An ACV variable showing anti-phase variations of the B and V light curves

HERMES spectroscopy of normal A and Am stars

A Binary Nature of the Marginal CP Star Sigma Sculptoris

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