A new look inside Planetary Nebula LoTr 5: A long-period binary with hints of a possible third component

DOI: 
10.1093/mnras/sty174
Publication date: 
01/01/2018
Main author: 
Aller, A.
IAA authors: 
Miranda, L. F.
Authors: 
Aller, A.;Lillo-Box, J.;Vučković, M.;Van Winckel, H.;Jones, D.;Montesinos, B.;Zorotovic, M.;Miranda, L. F.
Journal: 
Monthly Notices of the Royal Astronomical Society
Publication type: 
Article
Pages: 
1140-1150
Abstract: 
LoTr 5 is a planetary nebula with an unusual long-period binary central star. As far as we know, the pair consists of a rapidly rotating G-type star and a hot star, which is responsible for the ionization of the nebula. The rotation period of the G-type star is 5.95 days and the orbital period of the binary is now known to be ̃2700 days, one of the longest in central star of planetary nebulae. The spectrum of the G central star shows a complex Hα double-peaked profile which varies with very short time scales, also reported in other central stars of planetary nebulae and whose origin is still unknown. We present new radial velocity observations of the central star which allow us to confirm the orbital period for the long-period binary and discuss the possibility of a third component in the system at ̃129 days to the G star. This is complemented with the analysis of archival light curves from SuperWASP, ASAS and OMC. From the spectral fitting of the G-type star, we obtain a effective temperature of T<SUB>eff</SUB> = 5410±250 K and surface gravity of log g = 2.7±0.5, consistent with both giant and subgiant stars. We also present a detailed analysis of the Hα double-peaked profile and conclude that it does not present correlation with the rotation period and that the presence of an accretion disk via Roche lobe overflow is unlikely.
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2018MNRAS.476.1140A/abstract
ADS Bibcode: 
2018MNRAS.476.1140A
Keywords: 
planetary nebulae: individual: LoTr 5;binaries: general;techniques: radial velocities;techniques: photometric;stars: activity