Comet C/2022 E3 (ZTF)
Fig. 1 - Visitor from the last ice age: Comet C/2022 E3 (ZTF), photographed with a Teleskop-Service (TS) 65mm Quadruplet Astrograph on a ZWO AM5 mount.
| Object name: | Perihelion: | Aphelion: | Eccentricity: | Inclination: | Orbital period: |
|---|---|---|---|---|---|
| C/2022 E3 (ZTF) | 1.112 AU | ≈2800 AU | 0.999988 | 109.17° | ≈50,000 years |
The non-periodic comet C/2022 E3 (ZTF) from the Oort cloud, discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022. The comet has a bright green glow around its nucleus, due to the effect of sunlight on diatomic carbon and cyanogen. The comet's designation starts with C to indicate that it is not a periodic comet, and 2022 E3 means that it was the third comet to be discovered in the first half of March 2022.
The comet nucleus was estimated to be about a kilometer in size, rotating every 8.5 to 8.7 hours. The comet reached its perihelion (closest approach to the Sun) on January 12, 2023, at a distance of 1.11 AU (166 million km), and the closest approach to Earth was on February 1, 2023, at a distance of 0.28 AU (42 million km). The comet reached magnitude 5 and was visible with the naked eye under moonless dark skies (source: Wikipedia).
Eighteen 2-minute exposures (36 minutes total exposure) at gain 100 and -10°C, taken on January 28 / 29, 2023, were added for this shot with Astro Pixel Processor (APP) software and the final image processing was done in Photoshop. Darks, flats, bias and darkflats were used. During the imaging session, the comet was in the constellation Camelopardalis near Ursa Minor. The bright star in the lower left corner is HD 117566 (mag 5.88).
Equipment: Cooled ASI 2600MC Pro camera, Teleskop-Service (TS) 65mm f/6.5 Quadruplet Astrograph riding on a ZWO AM5 Strain Wave Mount, ZWO 30 mm Mini Guide Scope with an ASI 290MM Mini guide camera, ASIAIR Plus.