2015/05/07 by T. Mo nik, Teo Močnik, M. Lloyd +5 · 12 citations
Physics and Astronomy · #Amplitude #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Balmer series #Brightness #Emission spectrum #Light curve #Nebula #Physics #Spectral line #Stars #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stv983
published in Monthly Notices of the Royal Astronomical Society 451(1), 870-877 (Oxford University Press) · 9 pages, 6 figures (main article). 7 pages, 6 figures (appendix). Accepted for publication in MNRAS
arxiv created 2015/05/07 · arxiv updated 2015/05/08 · openalex publication_date 2015/05/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the analysis of several newly obtained and archived photometric and spectroscopic data sets of the intriguing and yet poorly understood 13.5 mag central star candidate of the bipolar planetary nebula Sh2-71. Photometric observations confirmed the previously determined quasi-sinusoidal light curve with a period of 68 d and also indicated periodic sharp brightness dips, possibly eclipses, with a period of 17.2 d. In addition, the comparison between U and V light curves revealed that the 68 d brightness variations are accompanied by a variable reddening effect of ΔE(U − V) = 0.38. Spectroscopic data sets demonstrated pronounced variations in spectral profiles of Balmer, helium and singly ionized metal lines and indicated that these variations occur on a time-scale of a few days. The most accurate verification to date revealed that spectral variability is not correlated with the 68 d brightness variations. The mean radial velocity of the observed star was measured to be ∼26 km s−1 with an amplitude of ±40 km s−1. The spectral type was determined to be B8V through spectral comparison with synthetic and standard spectra. The newly proposed model for the central star candidate is a Be binary with a misaligned precessing disc.