Zwicky Transient Facility

"ZTF" redirects here. For the long-period comet, see C/2022 E3 (ZTF).

The Zwicky Transient Facility (ZTF, obs. code: I41) is a wide-field sky astronomical survey using a new camera attached to the Samuel Oschin Telescope at Palomar Observatory in San Diego County, California, United States. Commissioned in 2018, it supersedes the (Intermediate) Palomar Transient Factory (2009–2017) that used the same observatory code. It is named after the Swiss astronomer Fritz Zwicky.^[1]

Zwicky Transient Facility

Alternative names	ZTF
Coordinates	33°21′26″N 116°51′35″W
Observatory code	I41
Website	ztf.caltech.edu

Description

The Samuel Oschin Telescope, used for the survey

Observing in visible and infrared wavelengths,^[2] the Zwicky Transient Facility is designed to detect transient objects that rapidly change in brightness, for example supernovae, gamma ray bursts, and collision between two neutron stars, and moving objects like comets and asteroids.

The new camera is made of 16 CCDs of 6144×6160 pixels each, enabling each exposure to cover an area of 47 square degrees. The Zwicky Transient Facility is designed to image the entire northern sky in three nights and scan the plane of the Milky Way twice each night to a limiting magnitude of 20.5 (r band, 5σ).^[3][4]

The amount of data produced by ZTF is expected to be ten times larger than its predecessor, the Intermediate Palomar Transient Factory.^[5] ZTF's large data allows it to act as a prototype for the Vera C. Rubin Observatory (formerly Large Synoptic Survey Telescope) that is expected to be in full operation in late 2025 and will accumulate ten times more data than ZTF.^[3][1]

First light was recorded of an area in the constellation Orion on November 1, 2017.^[6][7][8]

The first confirmed findings from the ZTF project were reported on 7 February 2018,^[9] with the discovery of 2018 CL, a small near-Earth asteroid.^[10]

Discoveries

• On 9 May 2019, ZTF discovered its first comet, C/2019 J2 (Palomar), a long-period comet.^[11]
• A search of the ZTF archive identified images of the interstellar comet 2I/Borisov as early as December 13, 2018, extending observations back eight months.^[12][13]
• 594913 ꞌAylóꞌchaxnim, the first asteroid discovered whose orbit is entirely within the orbit of Venus, was discovered by ZTF during its Twilight Survey.^[14]
• A search of ZTF's images identified cataclysmic variable star ZTF J1813+4251, a binary with a period of under 1 hour.^[15]
• AT2021lwx, a long-lasting high-energy transient with a redshift of 0.9945, was discovered on 13 April 2021.^[16][17][18]
• A very bright tidal disruption event called AT2022cmc with a redshift of 1.19325, among the brightest astronomical events ever observed.^[19][20]
• Comet C/2022 E3 (ZTF), which reached naked eye visibility in early 2023.

See also

• Vera C. Rubin Observatory – Astronomical observatory in Chile
• Pan-STARRS – Multi-telescope astronomical survey
• OGLE survey
• GOTO (telescope array)
• ATLAS