C/2020 S3 (Erasmus)

Last updated

C/2020 S3 (Erasmus)
C2020S3 2020-11-14 image ZTF-sso-319-zr-fov-13arcmin.png
Comet Erasmus photographed from the Zwicky Transient Facility on 14 November 2020
Discovery [1] [2]
Discovered by Nicolas Erasmus
Discovery site ATLASMLO (T08)
Discovery date17 September 2020
Designations
CK20S030 [2]
Orbital characteristics [3]
Epoch 11 March 2021 (JD 2459284.5)
Observation arc 436 days (1.19 years)
Number of
observations
861
Aphelion 389.268 AU
Perihelion 0.3985 AU
Semi-major axis 194.833 AU
Eccentricity 0.99795
Orbital period ~2,720 years
Inclination 19.861°
222.993°
Argument of
periapsis
349.886°
Mean anomaly 0.032°
Last perihelion12 December 2020
TJupiter 0.762
Earth MOID 0.315 AU
Jupiter MOID 0.584 AU
Physical characteristics [4]
Dimensions 1.6–2.4 km (0.99–1.49 mi)
Mean diameter
2.0 km (1.2 mi)
Comet total
magnitude
(M1)
13.0
Comet nuclear
magnitude (M2)
14.8
3.9
(2020 apparition) [5]

Comet Erasmus, formally designated as C/2020 S3, is a non-periodic comet which passed perihelion on 12 December 2020. Its maximum brightness peaked around an apparent magnitude of 4, however its proximity to the Sun at that time made it a difficult object to view from the ground. [6]

Contents

Observational history

The comet was discovered as an 18.5-magnitude object from four 30-second exposure images taken on 17 September 2020 from the ATLAS–MLO observatory in Mauna Loa, Hawaii. [7] It was initially flagged as a potential near-Earth asteroid until Dr. Nicolas Erasmus analyzed the images and noticed a faint coma around it shortly before announcing the discovery. [7]

It was visible in predawn skies as it made its closest approach to Earth at a distance of 1.09 AU (163 million km) on 19 November 2020. [8] Around this time, the comet was located within the constellation Hydra. [9]

It was predicted to reach a maximum brightness of magnitude 3.0–4.0 during its perihelion on 12 December 2020 at a distance of 0.4 AU (60 million km) from the Sun. However, the comet's position throughout December was too close to the Sun for ground observations, making it impossible to view at its brightest except from SOHO and STEREO-A. [6] [10]

Several observers were able to capture it during the total solar eclipse on 14 December 2020. [11]

Physical characteristics

The comet's linear polarization was measured between 13 and 23 November 2020, where astronomers have noted a similar performance as those seen from C/1989 X1 (Austin) and C/1996 B2 (Hyakutake), with models suggesting a decrease in the abundance of Mg–rich silicate particles in the inner coma by 1/3, revealing a change in the emanations of dust particles from the comet's nucleus. [12] Chemical analysis of the comet showed that its coma is enriched in formaldehyde (H2CO), ammonia (NH3), and acetylene (C2H2) compounds, however it is noticeably depleted of any methanol (CH3OH). [13]

During perihelion in December 2020, the comet's tail had exhibited wagging behaviour due to its interaction with a coronal mass ejection from the Sun. [6] Its water production rate reached a maximum of 3.5×1029 sec-1 around this time. [14] By the time it reached 1.45 AU (217 million km) on its outbound journey, its water production rate was still seven times higher than previously observed before perihelion, which was estimated to be around 1×1028 sec-1. [14]

The nucleus is estimated to be around 1.6–2.4 km (0.99–1.49 mi) in diameter. [4]

See also

References

  1. N. Erasmus; K. Yoshimoto; M. Mattiazzo; et al. (2020). D. W. Green (ed.). "Comet C/2020 S3 (Erasmus)" . Central Bureau for Astronomical Telegrams. 4855. Bibcode:2020CBET.4855....1E.
  2. 1 2 K. Yoshimoto; M. Mattiazzo; H. Sato; et al. (20 September 2020). "Comet C/2020 S3 (Erasmus)". Minor Planet Electronic Circulars. 2020-S119.
  3. "C/2020 S3 (Erasmus) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory . Retrieved 4 January 2024.
  4. 1 2 D. C. Jewitt (2022). "Destruction of Long-period Comets". The Astronomical Journal. 164 (4): 158–166. arXiv: 2208.04469 . Bibcode:2022AJ....164..158J. doi: 10.3847/1538-3881/ac886d .
  5. "COBS - Comet OBServation database: C/2020 S3 (Erasmus)". cobs.si. Retrieved 3 November 2025.
  6. 1 2 3 J. Li; Y. Kim; D. C. Jewitt (2023). "The Wagging Plasma Tail of Comet C/2020 S3 (Erasmus)". The Astronomical Journal. 166 (6): 270–287. arXiv: 2310.16219 . Bibcode:2023AJ....166..270L. doi: 10.3847/1538-3881/ad08af .
  7. 1 2 "SAAO Astronomer discovers new comet C/2020 S3 (Erasmus)". South African Astronomical Observatory. 23 September 2020. Retrieved 29 December 2024.
  8. M. Mattiazzo. "C/2020 S3 Erasmus". Southern Comets Homepage. Retrieved 29 December 2024.
  9. T. Phillips (21 November 2020). "Bright Comet Erasmus". SpaceWeather.com. Retrieved 29 December 2024.
  10. M. Olason (22 May 2021). "Comet C/2020 S3 (Erasmus)". Sky & Telescope. Retrieved 29 December 2024.
  11. "Total Solar Eclipse 2020 images, Argentina". www.zam.fme.vutbr.cz. Retrieved 14 May 2025.
  12. E. Chornaya; E. Zubko; A. Kochergin; M. Zheltobryukhov; et al. (2023). "C/2020 S3 (Erasmus): Comet with a presumably transient maximum of linear polarization Pmax" (PDF). Monthly Notices of the Royal Astronomical Society. 518 (2): 1617–1628. Bibcode:2023MNRAS.518.1617C. doi: 10.1093/mnras/stac3201 .
  13. C. Ejeta; E. Gibb; N. Roth; M. A. DiSanti; N. Dello Russo; et al. (2024). "Coma Abundances of Volatiles at Small Heliocentric Distances: Compositional Measurements of Long-period Comet C/2020 S3 (Erasmus)". The Astronomical Journal. 167 (1): 32–44. Bibcode:2024AJ....167...32E. doi: 10.3847/1538-3881/ad0e02 .
  14. 1 2 M. R. Combi; T. Mäkinen; J. L. Bertaux; E. Quémerais; S. Ferron (2023). "Water Production Rates from SOHO/SWAN Observations of Comets C/2020 S3 (Erasmus), C/2021 A1 (Leonard) and C/2021 O3 (PanSTARRS)". Icarus. 398 115543. arXiv: 2304.03333 . Bibcode:2023Icar..39815543C. doi:10.1016/j.icarus.2023.115543.