ZTFJ0038+2030: A Long-period Eclipsing White Dwarf and a Substellar Companion
Abstract
In a search for eclipsing white dwarfs using the Zwicky Transient Facility lightcurves, we identified a deep eclipsing white dwarf with an orbital period of 10.4 hr and an undetected substellar companion. We obtained high-speed photometry and radial velocity measurements to characterize the system. The white dwarf has a mass of 0.50 ± 0.02 M_☉ and a temperature of 10,900 ± 200 K. The companion has a mass of 0.059 ± 0.004 M_☉ and is a brown dwarf. It has a radius of 0.0783 ± 0.0013 R_☉, and is one of the physically smallest transiting brown dwarfs known and likely old, ≳8 Gyr. The ZTF discovery efficiency of substellar objects transiting white dwarfs is limited by the number of epochs and as ZTF continues to collect data we expect to find more of these systems.
Additional Information
© 2021. The American Astronomical Society. Received 2021 May 24; revised 2021 September 1; accepted 2021 September 1; published 2021 October 1. We thank the anonymous referee for detailed and constructive feedback. J.vR. is partially supported by NASA-LISA grant 76280NSSC19K0325. K.J.B. is supported by the National Science Foundation under Award AST-1903828. We thank Lars Bildsten for trading one hour of ESI-Keck time. Based on observations obtained with the Samuel Oschin 48 inch Telescope and the 60 inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under grant No. AST-1440341 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW. Based on observations obtained with the 200 inch Hale Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. The Hale telescope is operated by the Caltech Optical Observatories. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Facilities: PO:1.2 m (ZTF) - , Hale (CHIMERA) - , Keck:II (ESI) - . Software: VizieR, astropy (Astropy Collaboration et al. 2013), NumPy (Harris et al. 2020), SciPy (Virtanen et al. 2020), matplotlib (Hunter 2007), Makee, ellc (Maxted et al. 2014), emcee (Foreman-Mackey et al. 2013).Attached Files
Published - van_Roestel_2021_ApJL_919_L26.pdf
Submitted - 2105.08687.pdf
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Additional details
- Eprint ID
- 109401
- Resolver ID
- CaltechAUTHORS:20210604-142603248
- NASA
- 76280NSSC19K0325
- NSF
- AST-1903828
- NSF
- AST-1440341
- ZTF partner institutions
- W. M. Keck Foundation
- NSF Astronomy and Astrophysics Postdoctoral Fellowship
- Created
-
2021-06-07Created from EPrint's datestamp field
- Updated
-
2021-10-05Created from EPrint's last_modified field
- Caltech groups
- Astronomy Department, Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility, Division of Geological and Planetary Sciences