First Light

On Nov. 14, the Zwicky Transient Facility, a powerful new astronomical sky survey, announced that it had achieved first light and taken its first detailed images of the night sky.

When fully operational in 2018, the ZTF will scan almost the entire northern sky every night. Based at the Palomar Observatory in southern California and operated by Caltech, the ZTF’s goal is to use these nightly images to identify “transient” objects that vary between observations — identifying events ranging from supernovae millions of light years away to near-Earth asteroids. University of Washington, along with seven other institutions, is a member of the ZTF Partnership who will make use of ZTF’s data.

At DIRAC, our team is developing new methods to identify the most scientifically interesting of the millions of changes in the sky that the ZTF will detect each night and alert scientists. That way, these high-priority transient objects can be followed up in detail by larger telescopes, such as the Apache Point Observatory 3.5-meter telescope. DIRAC scientists are also exploring new approaches to handling large time series databases in order to find rare and exotic variable objects, as well as novel asteroid discovery techniques in preparation for the LSST.

ZTF First Light Gallery

ZTF took this “first-light” image on Nov. 1, 2017, after being installed at the 48-inch Samuel Oschin Telescope at Palomar Observatory. The full-resolution version is more than 24,000 pixels by 24,000 pixels. Each ZTF image covers a sky area equal to 247 full moons. The Orion nebula is at lower right. Computers searching these images for transient, or variable, events are trained to automatically recognize and ignore non-astronomical sources, such as the vertical “blooming” lines seen here. Image credit: Caltech Optical Observatories

The “first-light” image from ZTF is shown here (inset) within the Orion constellation. The Orion nebula can be seen within the ZTF image. Each ZTF image covers an area of sky equivalent to 247 full moons. Such large images will enable the camera to scan the sky quickly to discover objects that move or change in brightness, such as asteroids and supernovas, even when rare and short lived. Image credit: Caltech Optical Observatories

The Horsehead nebula can be seen in this portion of the “first-light” image from ZTF. The head of the horse (middle) faces up toward another well-known nebula known as the Flame. Violet to green wavelengths detected by ZTF are represented as cyan, while yellow to deep red wavelengths are shown as red. Computers searching these images for transient, or variable, events are trained to automatically recognize and ignore non-astronomical sources, such as the vertical “blooming” lines seen here. Image credit: Caltech Optical Observatories

The Samuel Oschin 48″ telescope at Mt. Palomar, where the ZTF Survey takes place.

The ZTF is funded by the National Science Foundation and its partner institutions. The UW’s participation with the ZTF was made possible by funds provided by the College of Arts & Science, the DIRAC Institute and the Washington Research Foundation. The DIRAC Institute is funded in part by the Charles and Lisa Simonyi Fund for Arts and Sciences.

More Information

• ZTF work at the University of Washington
• Zwicky Transient Facility website
• ZTF movie
• UW Press Release
• Caltech Press Release