A state-of-the-art astronomical camera system in California known as the Zwicky Transient Facility is rolling out an early batch of greatest hits with an assist from the University of Washington.
The wide-angle camera makes use of the 48-inch Samuel Oschin Telescope at Southern California’s Palomar Observatory, with Caltech playing the principal role in the $24 million project. But UW is one of the partners in the ZTF consortium, and UW’s DIRAC Institute plays a key role in the automated alert system that lets astronomers know when the instrument has picked up a hot one.
Technical details and early results from the ZTF are laid out in a flurry of six papers accepted by the Publications of the Astronomical Society of the Pacific. The discoveries include more than 1,100 supernovae and 50 near-Earth asteroids. One of the finds is a strange space rock known as 2019 AQ3. It makes an orbit around the sun every 165 days, which gives it the shortest “year” of any known asteroid.
“It’s a cornucopia of results,” Caltech astronomer Shri Kulkarni, the ZTF project’s principal investigator, said in a news release. “We are up and running and delivering data to the astronomical community. Astronomers are energized.”
UW astronomer Eric Bellm, the project’s survey scientist and the lead author for one of the newly published papers, said that the early results demonstrate ZTF’s ability to pick up on fast-fading phenomena, known as transients, and get the word out in a matter of seconds for follow-up by other instruments.
“The ZTF mission is to identify changes in the night sky and alert the astronomical field of these discoveries as quickly as possible,” Bellm said in a news release. “The results and specifications reported in these six papers demonstrate that the ZTF has in place a pipeline to identify new objects, as well as analyze and disseminate information about them quickly to the astronomy community.”
The Zwicky Transient Facility is named after the late Caltech astronomer Fritz Zwicky, who’s best known for picking up the first clues to the existence of dark matter back in the early 1930s.
Caltech and its partners brought the ZTF to its “first light” milestone in November 2017, and began science operations in March 2018.
Bellm said the ZTF’s alert system serves as a proving ground for future “automated, time-domain astronomy” missions such as the Large Synoptic Survey Telescope, currently under construction in Chile. The LSST, which is expected to begin its sky surveys in 2022, should generate about 10 million alerts per night, which is about 10 times the maximum alert volume of the ZTF.
Papers accepted for publication include:
“The Zwicky Transient Facility: Science Objectives” by Matthew Graham et al.
“The Zwicky Transient Facility: Data Processing, Products, and Archive” by Frank Masci et al.
“Machine Learning for the Zwicky Transient Facility” by Ashish Mahabal et al.
“The Zwicky Transient Facility Alert Distribution System” by Maria Patterson et al.
“The GROWTH Marshal: A Dynamic Science Portal for Time-domain Astronomy” by Mansi Kasliwal et al.
The ZTF is funded by the National Science Foundation, the Heising-Simons Foundation and the ZTF member institutions. In addition to Caltech and UW, those partners include the Weizmann Institute of Science, the Oskar Klein Centre at Stockholm University, the University of Maryland, the Deutsches Elektronen-Synchrotron, Humboldt University of Berlin, the TANGO Consortium of Taiwan, the University of Wisconsin-Milwaukee and the Lawrence Berkeley National Laboratory.