MOST photometry of the enigmatic PMS pulsator HD 142666

Abstract

We present precise photometry of the pulsating Herbig Ae star HD 142666 obtained in two consecutive years with the MOST (Microvariability & Oscilations of STars) satellite. Previously, only a single pulsation period was known for HD 142666. The MOST photometry reveals that HD 142666 is multi-periodic. However, the unique identification of pulsation frequencies is complicated by the presence of irregular variability caused by the star's circumstellar dust disk. The two light curves obtained with MOST in 2006 and 2007 provided data of unprecedented quality to study the pulsations in HD 142666 and also to monitor the circumstellar variability. We attribute 12 frequencies to pulsation. Model fits to the three frequencies with the highest amplitudes lie well outside the uncertainty box for the star's position in the HR diagram based on published values. The models suggest that either (1) the published estimate of the luminosity of HD 142666, based on a relation between circumstellar disk radius and stellar luminosity, is too high and/or (2) additional physics such as mass accretion may be needed in our models to accurately fit both the observed frequencies and HD 142666's position in the HR diagram.

arXiv comment10 pages, 11 figures, accepted for publication by Astronomy and Astrophysics

References in corpus (11)

• Astrophysical parameters of Galactic open clusters
• The near-infrared size-luminosity relations for Herbig Ae/Be disks
• SigSpec - I. Frequency- and Phase-Resolved Significance in Fourier Space
• An Upper Limit on the Albedo of HD 209458b: Direct Imaging Photometry with the MOST Satellite
• Understanding the spectra of isolated Herbig stars in the frame of a passive disk model
• A heuristic derivation of the uncertainty of the frequency determination in time series data
• The Instability Strip for Pre--Main-Sequence Stars
• Discovery of the new slowly pulsating B star HD 163830 (B5II/III) from MOST spacebased photometry
• Comparing the observational instability regions for pulsating pre-main sequence and classical $\delta$ Scuti stars
• Reduction of time-resolved space-based CCD photometry developed for MOST Fabry Imaging data
• Comparative seismology of pre- and main sequence stars in the instability strip

Cited by in corpus (13)

• Consistent dust and gas models for protoplanetary disks III. Models for selected objects from the FP7 DIANA project
• Dippers and Dusty Disks Edges: A Unified Model
• Echography of young stars reveals their evolution
• Herbig Stars: A Quarter Century of Progress
• Precise High-Cadence Time Series of Five Variable Young Stars in Auriga with MOST
• Simultaneous spectral energy distribution and near-infrared interferometry modeling of HD 142666
• Rotational Splitting of Pulsational Modes
• MOST observations of the Herbig Ae δ-Scuti star HD 34282
• Photometric variability of the Herbig Ae star HD 37806
• The inner circumstellar disk of the UX Ori star V1026 Sco
• The Pre-main Sequence: Challenges and Prospects for Asteroseismology
• The VMC survey -- XXXVI. Young stellar variability in the Large Magellanic Cloud
• Tracing early stellar evolution with asteroseismology: pre-main sequence stars in NGC 2264