Binary central stars of planetary nebulae discovered through photometric variability. V. The central stars of HaTr 7 and ESO 330-9

Todd C. Hillwig, David J. Frew, Nicole Reindl, Hannah Rotter, Andrew Webb, Steve Margheim

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We find the central stars (CSs) of the planetary nebulae (PNe) HaTr 7 and ESO 330-9 to be close-binary systems. Both have orbital periods of less than half a day and contain an irradiated cool companion to the hot CS. We provide light curves, spectra, radial velocity curves, orbital periods, and binary modeling results for both systems. The binary modeling leads to system parameters, or ranges of allowed parameters for each system. We find that for the CS of HaTr 7 we need to use limb-darkening values for the cool companion that are different than the expected values for an isolated star. We also fit the CS spectrum to determine log g and temperature values independent of the binary modeling. For ESO 330-9 we find that based on our binary modeling, the hot CS is most likely a postred giant branch (RGB) star with a mass of around 0.4 Ṁ. We discuss our derived stellar and nebular parameters in the broader context of close-binary CSs and their surrounding planetary nebulae (PNe). We also discuss the present status of known or suspected post-RGB stars in PNe.

Original languageEnglish
Article number24
Pages (from-to)1-12
Number of pages12
JournalAstronomical Journal
Volume153
Issue number1
DOIs
Publication statusPublished - 1 Jan 2017
Externally publishedYes

Keywords

  • binaries: close
  • planetary nebulae: individual (PN HaTr 7, ESO 330-9)

Fingerprint Dive into the research topics of 'Binary central stars of planetary nebulae discovered through photometric variability. V. The central stars of HaTr 7 and ESO 330-9'. Together they form a unique fingerprint.

Cite this