Searching for binary central stars of planetary nebulae with Kepler

TL;DR

This study utilizes Kepler's high-precision photometry to detect binary companions around planetary nebulae's central stars, revealing new potential binaries and improving detection capabilities for faint or distant companions.

Contribution

It demonstrates the use of Kepler data to identify binary central stars of planetary nebulae with unprecedented sensitivity and cadence, expanding the known population of such binaries.

Findings

Confirmed three binary central stars through periodic variability.

Detected weak periodicities in two other objects, indicating possible binarity.

Prepared to analyze data for the central star of Kn 61, promising further discoveries.

Abstract

The Kepler Observatory offers unprecedented photometric precision (<1 mmag) and cadence for monitoring the central stars of planetary nebulae, allowing the detection of tiny periodic light curve variations, a possible signature of binarity. With this precision free from the observational gaps dictated by weather and lunar cycles, we are able to detect companions at much larger separations and with much smaller radii than ever before. We have been awarded observing time to obtain light-curves of the central stars of the six confirmed and possible planetary nebulae in the Kepler field, including the newly discovered object Kn 61, at cadences of both 30 min and 1 min. Of these six objects, we could confirm for three a periodic variability consistent with binarity. Two others are variables, but the initial data set presents only weak periodicities. For the central star of Kn 61, Kepler data will be available in the near future.