White Dwarf Variables in the Zwicky Transient Facility's Concurrent Observations of TESS Sector 14
ATel #12959; Burdge, Kevin B., Lin Yan, T. Prince, S. R. Kulkarni, M. J. Graham, D. Duev, C. Fremling, J. van Roestel (Caltech), E. Bellm (UW), F. Masci (IPAC)
on 25 Jul 2019; 17:52 UT
Credential Certification: Lin Yan (lyan@caltech.edu)
Subjects: Optical, Nova, Transient
As highlighted in ATel #12952, the Zwicky Transient Facility (ZTF) began nightly concurrent observations of TESS sector 14 on July 18, 2019, with a cadence of one g band and one r band exposure per night. As described in ATel #12952, the first three nights of observations yielded four transient candidates. Here, we report detections of three candidate white dwarf variables selected via a cross match of publically accessible ZTF alerts in TESS sector 14 with a catalog of candidate white dwarfs (https://arxiv.org/abs/1807.03315). These objects all exhibit peak apparent magnitudes bright enough to benefit from TESS observations.
Further followup is encouraged.
Name | R.A. | Dec. | Delta(mag) | r-mag |
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WDJ202259.39+523905.61 | 20:22:59.3600 | +52:39:05.404 | 8 | 14
WDJ202259.39+523905.61 | 20:22:59.3600 | +52:39:05.404 | 8 | 14
WDJ204627.92+242218.76 | 20:46:27.9338 | +24:22:18.591 | 4.5 | 15
WDJ194125.05+152255.30 | 19:41:24.9937 | +15:22:54.264 | 1 | 16
WDJ192856.45+430537.08 | 19:28:56.4451 | +43:05:37.355 | 3 | 15
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ZTF plans to conduct a public, nightly concurrent survey of all 13 TESS northern sectors in 2019-2020. The ZTF transient alerts in the TESS fields will have the keyword "programpi" in the
candidate block set to "TESS". In addition to the ZTF alert streams provided by various alert brokers, all ZTF-TESS alerts will be released nightly to the public via ZTF's bucket on Google Cloud in a compressed tarball with the alert packets converted into JSON format. Details on how to access these alerts are given in the following Jupyter notebook: https://colab.research.google.com/github/dmitryduev/kowalski/blob/master/nb/tess.ipynb. ZTF-TESS alerts will also be cross-matched against a number of external catalogs, including 2MASS PSC, AllWISE, IPHAS DR2 and Gaia DR2. While nightly observations are planned, in the event of bad weather or system problems,
no tarball will be generated.
We anticipate that ZTF light curves for all objects observed concurrently by TESS and ZTF will be made available publically within one month of the end of a TESS sector observation campaign. Details on how to access the ZTF light curve data will be given in the Jupyter notebook mentioned above. These light curves are constructed from sources extracted from the undifferenced epochal science images, using seed detections from the deeper reference images (co-adds).
ZTF is a project led by PI S. R. Kulkarni at Caltech (see ATEL #11266), and includes IPAC; WIS, Israel; OKC, Sweden; JSI/UMd, USA; UW,USA; DESY, Germany; NRC, Taiwan; UW Milwaukee, USA and LANL USA. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. Alert distribution service provided by DIRAC@UW. Alert filtering is being undertaken by the GROWTH marshal system, supported by NSF PIRE grant 1545949. We acknowledge the support from the Heising-Simons Foundation under Grant No. 12540303.
