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A Binary Nature of the Marginal CP Star Sigma Sculptoris
Krtička, Jiří; Paunzen, Ernst; Adam, Christian +7 more
The A2 V star σ Scl was suspected of being a low-amplitude rotating variable of the Ap-type star by several authors. Aiming to decide 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 sev…
Variability Analysis of δ Scuti Candidate Stars
Tautvaišienė, Gražina; Pakštienė, Erika; Janulis, Rimvydas +5 more
The Hipparcos catalog contains stars suspected to be δ Scuti variables for which extensive ground-based observations and characterization of variability are necessary. Our aim was to characterize variability of 13 candidates to δ Scuti type stars. We obtained 24 215 CCD images and analyzed stellar light curves using the Period04 program. Twelve δ …
Mean Occupation Function of High-redshift Quasars from the Planck Cluster Catalog
Myers, Adam D.; Chakraborty, Priyanka; Chatterjee, Suchetana +1 more
We characterize the distribution of quasars within dark matter halos using a direct measurement technique for the first time at redshifts as high as z ∼ 1. Using the Planck Sunyaev-Zeldovich (SZ) catalog for galaxy groups and the Sloan Digital Sky Survey (SDSS) DR12 quasar data set, we assign host clusters/groups to the quasars and make a measurem…
Precision Time-series Photometry in the Thermal Infrared with a “Wall-eyed” Pointing Mode at the Large Binocular Telescope
Skemer, Andrew; Spalding, Eckhart; Hinz, Phil +3 more
Time-series photometry taken from ground-based facilities is improved with the use of comparison stars due to the short timescales of atmospheric-induced variability. However, the sky is bright in the thermal infrared (3-5 µm), and the correspondingly small fields of view of available detectors make it highly unusual to have a calibration st…
Study of CoRoT 105415473: A Heartbeat Star with δ Scuti Oscillations
Chou, Dean-Yi; Fernández Fernández, Javier
We study the light curves of CoRoT 105415473 with the CoRoT satellite photometric data of 144 days. The light curves consist of two types of temporal variations: periodic brightening and pulsational. The periodic brightening suggests that the variations are from a binary system without eclipsing, with an orbital period of 2.6 days. The frequency a…