On ε-mechanism-driven pulsations in VV 47. Issue 2 (22nd June 2018)

• Record Type: Journal Article
• Authors: Sowicka, Paulina; Handler, Gerald; Jones, David
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 479:Issue 2(2018)
• Page Start: 2476
• Page End: 2480
• Publication Date: 2018-06-22
• Subjects: stars: individual: PN VV 47 -- stars: oscillations -- white dwarfs; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty1660
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We report new observations of the central star of the planetary nebula VV 47 carried out to verify earlier assertions that the short-period pulsation modes detected in the star are driven by the ε-mechanism. In our data, VV 47 was not variable up to a limit of 0.52 mmag in the Fourier amplitude spectrum up to the Nyquist frequency of 21.7 mHz. Given this null result we re-analysed the data set in which oscillations were claimed. After careful data reduction, photometry, extinction correction, and analysis with a conservative criterion of S/N ≥ 4 in the Fourier amplitude spectrum, we found that the star was not variable during the original observations. The oscillations reported earlier were due to an over-optimistic detection criterion. We conclude that VV 47 did not pulsate during any measurements at hand; the observational detection of ε-driven pulsations remains arduous.