Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 24, 2019 | Accepted Version + Supplemental Material
Journal Article Open

General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system


General relativity predicts that short-orbital-period binaries emit considerable amounts of gravitational radiation. The upcoming Laser Interferometer Space Antenna (LISA) is expected to detect tens of thousands of such systems but few have been identified4, of which only one5 is eclipsing—the double-white-dwarf binary SDSS J065133.338+284423.37, which has an orbital period of 12.75 minutes. Here we report the discovery of an eclipsing double-white-dwarf binary system, ZTF J153932.16+502738.8, with an orbital period of 6.91 minutes. This system has an orbit so compact that the entire binary could fit within the diameter of the planet Saturn. The system exhibits a deep eclipse, and a double-lined spectroscopic nature. We see rapid orbital decay, consistent with that expected from general relativity. ZTF J153932.16+502738.8 is a strong source of gravitational radiation close to the peak of LISA's sensitivity, and we expect it to be detected within the first week of LISA observations, once LISA launches in approximately 2034.

Additional Information

© 2019 Springer Nature Publishing AG Received 21 February 2019. Accepted 23 May 2019. Published 24 July 2019. K.B.B. thanks the National Aeronautics and Space Administration and the Heising Simons Foundation for supporting his research. This work was based on observations obtained with the Samuel Oschin Telescope 48-inch 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 number 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 (UW), Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, and the Lawrence Berkeley National Laboratories. Operations are conducted by Caltech Optical Observatories, IPAC, and the University of Washington. The KPED team thanks the National Science Foundation and the National Optical Astronomical Observatory for making the Kitt Peak 2.1-m telescope available. The KPED team thanks the National Science Foundation, the National Optical Astronomical Observatory and the Murty family for support in the building and operation of KPED. In addition, they thank the CHIMERA project for use of the Electron Multiplying CCD (EMCCD). 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. We wish to recognize and acknowledge the very important cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This research benefited from interactions at the ZTF Theory Network Meeting that were funded by the Gordon and Betty Moore Foundation through grant GBMF5076 and support from the National Science Foundation through PHY-1748958. We thank J. Hoffman, the creator of cuvarbase. We thank T. Marsh, S. Phinney and V. Korol for discussions. We thank G. Hallinan and C. Fremling for helping to observe the object. Author Contributions: K.B.B. discovered the object, conducted the lightcurve analysis and eclipse time analysis, and was the primary author of the manuscript. K.B.B. and M.W.C. conducted the spectroscopic analysis. K.B.B., M.W.C. and T.A.P. conducted the combined mass–radius analysis. K.B.B. and M.W.C. reduced the optical data. K.B.B., M.W.C. and D.L.K. reduced and analysed the X-ray observations. J.F. conducted the theoretical analysis, including that on tides, and developed the MESA evolutionary models. K.B.B., M.W.C., T.K., S.R.K., J.v.R. and T.A.P. all contributed to collecting data on the object. K.B.B., M.W.C., J.F., T.K., E.C.B., L.B., M.J.G., D.L.K., J.v.R., S.R.K. and T.A.P. contributed to the physical interpretation of the object. T.K., E.C.B., R.G.D., M.F., M.G., S.K., R.R.L., A.A.M., F.J.M., R.R., D.L.S., M.T.S., R.M.S., P.S. and R.W. contributed to the implementation of ZTF; M.J.G. is the project scientist, T.A.P. and G.H. are co-PIs, and S.R.K. is the PI of ZTF. R.G.D., D.A.D., M.F. and R.R. contributed to the implementation of KPED; M.W.C. is project scientist, and S.R.K. is PI of KPED. T.A.P. is K.B.B.'s PhD advisor. Data availability: Upon request, K.B.B. will provide reduced photometric and spectroscopic data, and available ZTF data for the object. We have included the eclipse time data used to construct the orbital decay diagram in Fig. 2a, and Extended Data Figs. 2 and 3. The X-ray observations are already in the public domain, and their observation IDs have been supplied in the text. The proprietary period for the spectroscopic data will expire at the start of 2020, at which point this data will also be public and readily accessible. Code availability: Upon request, K.B.B. will provide the code (primarily in Python) used to analyse the observations and data such as the posterior distributions used to produce the figures in the text (MATLAB was used to generate most of the figures). The authors declare no competing interests.

Attached Files

Accepted Version - 1907.11291.pdf

Supplemental Material - 41586_2019_1403_Fig10_ESM.jpg

Supplemental Material - 41586_2019_1403_Fig5_ESM.jpg

Supplemental Material - 41586_2019_1403_Fig6_ESM.jpg

Supplemental Material - 41586_2019_1403_Fig7_ESM.jpg

Supplemental Material - 41586_2019_1403_Fig8_ESM.jpg

Supplemental Material - 41586_2019_1403_Fig9_ESM.jpg

Supplemental Material - 41586_2019_1403_MOESM1_ESM.csv

Supplemental Material - 41586_2019_1403_Tab1_ESM.jpg


Files (4.5 MB)
Name Size Download all
140.4 kB Preview Download
282.8 kB Preview Download
3.0 MB Preview Download
144.9 kB Preview Download
392.1 kB Preview Download
335.6 kB Preview Download
109.1 kB Preview Download
1.1 kB Preview Download
52.4 kB Preview Download

Additional details

August 19, 2023
October 20, 2023