{
  "id": "2410.13939",
  "version": "v1",
  "published": "2024-10-17T18:00:05.000Z",
  "updated": "2024-10-17T18:00:05.000Z",
  "title": "A search for self-lensing binaries with TESS and constraints on their occurrence rate",
  "authors": [
    "Natsuko Yamaguchi",
    "Kareem El-Badry"
  ],
  "comment": "24 pages, 17 figures, submitted to PASP",
  "categories": [
    "astro-ph.SR",
    "astro-ph.EP"
  ],
  "abstract": "Five self-lensing binaries (SLBs) have been discovered with Kepler light curves. They contain white dwarfs (WDs) in AU-scale orbits that gravitationally lens solar-type companions. Forming SLBs likely requires common envelope evolution when the WD progenitor is an AGB star and has a weakly bound envelope. No SLBs have yet been discovered with data from the Transiting Exoplanet Survey Satellite (TESS), which observes far more stars than Kepler did. Identifying self-lensing in TESS data is made challenging by the fact that TESS only observes most stars for $\\sim$25 days at a time, so only a single lensing event will be observed for typical SLBs. TESS's smaller aperture also makes it sensitive only to SLBs a factor of $\\sim$100 brighter than those to which Kepler is sensitive. We demonstrate that TESS has nevertheless likely already observed $\\sim$4 times more detectable SLBs than Kepler. We describe a search for non-repeating self-lensing signals in TESS light curves and present preliminary candidates for which spectroscopic follow-up is ongoing. We calculate the sensitivity of our search with injection and recovery tests on TESS and Kepler light curves. Based on the 5 SLBs discovered with Kepler light curves, we estimate that $(1.1 \\pm 0.6)\\%$ of solar-type stars are orbited by WDs with periods of 100-1000 d. This implies a space density of AU-scale WD + main sequence (MS) binaries a factor of 20-100 larger than that of astrometrically-identified WD + MS binaries with orbits in Gaia DR3. We conclude that the Gaia sample is still quite incomplete, mainly because WD + MS binaries can only be unambiguously identified as such for high mass ratios.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-10-17T18:00:05.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "kepler light curves",
      "self-lensing binaries",
      "occurrence rate",
      "constraints",
      "ms binaries"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}