Kepler/K2 Bright Stars

While Kepler was engineered primarily to look at thousands of faint stars to do population statistics, planets transiting naked-eye stars, like the super-Earth 55 Cnc e, are the best targets for detailed characterization. Unfortunately, stars this bright saturate the Kepler and TESS detectors, making them hard or impossible to observe conventionally. Using 'smear' and 'halo' photometry, we can achieve normal Kepler-like precision on stars orders of magnitude brighter than it was ever meant to observe.

Smear Photometry

Collateral "smear" data, normally used as a calibration step for calibrating Kepler photometry, to obtain light curves of stars too bright to observe conventionally. This is described in greater detail in our MNRAS Letters paper. Many stars in the Kepler and K2 fields were unobserved/under-observed because of saturation, and smear photometry opens up a new window on the Kepler archive.

We have just released data and a paper (accepted ApJS) for the Kepler Smear Campaign*, using smear to obtain light curves of the 102 brightest (Kp<9) stars in Kepler that were not otherwise observed. The main goal of this project is to characterize some of the nearest stars as completely as possible to use as benchmark stars, using a combination of asteroseismology (Kepler/K2), interferometry (CHARA) and spectroscopy. Light curves for the smear campaign are available on GitHub or from MAST. Check out this Bokeh interactive HR diagram of the smear campaign sample overlaid on the gaia-kepler.fun sample.

Halo Photometry

I'm also collaborating with Tim White (ANU) on 'halo photometry', a new method of photometry using weighted sums of unsaturated pixels to minimize instrumental systematics. This has revealed variability in the Seven Sisters of the Pleiades and oscillations in the red giant Aldebaran. We have used this to produce a systematic reduction of all the naked-eye stars in K2, published in ApJS and on arXiv. The paper source code, documentation and lightcurves for this K2 Bright Star Survey are available on GitHub and the light curves are available as a High Level Science Product on MAST. As with the smear campaign - see this Bokeh interactive HR diagram of the halo campaign sample.

*You can blame Andy Casey for this suggestion.

Get In Touch

  • Address

    School of Mathematics and Physics
    The University of Queensland
    St Lucia
    QLD 4072
    Australia
  • Email

    b.pope@uq.edu.au