ZTF

A 47 deg²square degreeUnit of solid angle: one degree by one degree on the sky. The whole sky is about 41,253 deg²; the full Moon covers about 0.2 deg². camera of sixteen 6k × 6k CCDsCCDCharge-coupled device: a silicon pixel array that stores photo-electrons and shifts them to a readout amplifier. The workhorse optical detector; in X-rays, each photon's charge also measures its energy. on the 1.2 m Samuel Oschin SchmidtSchmidt telescopeA wide-field design: a spherical primary mirror with a thin corrector plate at its centre of curvature, giving sharp images over several degrees. Used by survey instruments such as ZTF and Kepler. at Palomar, covering about 3,750 deg² per hour to r ≈ 20.5 in 30-second exposures in g, r and i. The public survey revisits the northern sky every two nights and streams difference-imaging alertsalertA machine-readable notice that a source has appeared, changed or been detected, issued within seconds to days so other facilities can follow up. Optical alerts reach users through brokers; high-energy, neutrino and gravitational-wave alerts through GCN. to brokersalert brokerA service that ingests an alert stream (from ZTF or Rubin, up to millions of alerts a night), cross-matches and classifies each alert, and lets users filter for what they need. Examples: ALeRCE, Fink, Lasair, ANTARES.: the main discovery engine for bright supernovae, tidal disruption events and near-Earth asteroids until Rubin.

Operator

Caltech, NSF

Site

Palomar Observatory, California

Aperture

1.2 m Schmidt

Passband

400 nm – 900 nm

Survey start

20 March 2018