Welcoming ZTF to the IAWN

(Aug 2018) IAWN would like to welcome the Zwicky Transient Facility, or ZTF to the IAWN as of July 2018! Below we provide a bit of information on the project.

Beginning in early 2018, the Zwicky Transient Facility or ZTF (a collaboration led by the California Institute of Technology; see ATel #11266) began operation. On February 5 of this year (2018), ZTF discovered their first NEO, designated 2018 CL by the Minor Planet Center. Since this time, the ZTF has discovered several more NEOs, as well as a ~1000 main belt asteroids.

Star trails over Palomar Schmidt Dome

Palomar Schmidt Dome
ZTF website at Caltech
Credit: Palomar/Caltech

The ZTF uses the 1.2m Palomar Oschin Schmidt telescope and a large mosaic of CCDs to cover over 3500 square degrees of sky per hour to around V magnitude = 20.5. This wide area coverage and faint limit will allow the ZTF to discover NEOs that are fainter than discoveries that would normally be picked up by either the ATLAS telescope, (https://fallingstar.com/home.php) or the Catalina Sky Survey Schmidt telescope (https://catalina.lpl.arizona.edu/) which cover similarly large areas of sky. These three systems together represent a significant advance in planetary defense, as they are able to cover significantly larger portions of the sky than traditional surveys and allow for improved and increased warning for small objects on impacting trajectories. ZTF's sky coverage is sufficiently large that it should also allow repeated observations of most main-belt asteroids down to V magnitude fainter than 20. Readers should be aware that a larger catalog of main-belt asteroids facilitates easier NEO detection, and easier operation of these surveys.

The Palomar Oschin Schmidt has historically been a pioneer observing facility for NEO discovery. Several large and important NEO discoveries were made using photographic plates during the Palomar Sky Survey in the late 1940s and early 1950s. These discoveries include (1566) Icarus and (1620) Geographos. While conducting the second Palomar Sky Survey in the 1980s and 1990s, a few dozen NEOs and comets were discovered. During the early 2000s, the Oschin Schmit was used for over 300 NEO discoveries as part of the NEAT survey run by Eleanor Helin. It is nice to see this facility in routine operation again, and we look forward to more NEO discoveries in the future.