C/2020 A2 (Iwamoto)

For the 2013 and 2018 comets of the same name, see C/2013 E2 (Iwamoto) and C/2018 Y1 (Iwamoto).

C/2020 A2 (Iwamoto)

Comet C/2020 A2 (Iwamoto) photographed from the Zwicky Transient Facility on 19 February 2020.
Discovery [1] [2]
Discovered by	Masayuki Iwamoto
Discovery site	Tokushima, Japan
Discovery date	8 January 2020
Designations
Alternative designations	CK20A020, [2] IF033 [3]
Orbital characteristics [4]
Epoch	23 February 2020 (JD 2458902.5)
Observation arc	104 days
Number of observations	529
Aphelion	~2,120 AU
Perihelion	0.978 AU
Semi-major axis	~1,060 AU
Eccentricity	0.99908
Orbital period	~34,500 years
Inclination	120.75°
Longitude of ascending node	286.38°
Argument of periapsis	68.209°
Mean anomaly	0.0013°
Last perihelion	8 January 2020
TJupiter	–0.622
Earth MOID	0.312 AU
Jupiter MOID	1.129 AU
Physical characteristics
Comet total magnitude (M1)	15.1
Comet nuclear magnitude (M2)	17.2
Apparent magnitude	9.6 [5] (2020 apparition)

Comet Iwamoto, formally designated as C/2020 A2 is a faint non-periodic comet that was observed between January and April 2020. As of 2025 ^[update] , it is the fourth and most recent comet discovered by Japanese astronomer, Masayuki Iwamoto. ^{[6] [a]}

Observational history

Masayuki Iwamoto reported a new 14th-magnitude object with cometary features on the night of 8 January 2020, which was moving gradually north within the constellation Ophiuchus. ^{[3] [b]} Nearly five days later, Gennadiy Borisov confirmed the existence of Iwamoto's new comet, reporting that it has a diffuse coma about 40 arcseconds in diameter. ^[2] Additional observations from the Xingming Observatory, Magdalena Ridge Observatory, and other sites between 10 and 14 January 2020 reveal that the comet does not have a tail at the time. ^[7]

References

Notes

1. This figure includes C/2018 V1 (Machholz–Fujikawa–Iwamoto), which Iwamoto had co-discovered with Donald Machholz and Shigehisa Fujikawa
2. Reported initial position upon discovery was: α = 17^h 52^m 58.28^s, δ = 5° 44′ 30″ ^[2]

Citations

1. M. Iwamoto (January 2020). D. W. Green (ed.). "Comet C/2020 A2 (Iwamoto)" . Central Bureau for Astronomical Telegrams. 4714 (1).
2. M. Iwamoto; G. Borisov; et al. (18 April 2024). "Comet C/2020 A2 (Iwamoto)". Minor Planet Electronic Circulars. 2020-A132. ISSN   1523-6714.
3. N. James (15 January 2020). "Comet C/2020 A2 (Iwamoto)". britastro.org. British Astronomical Association . Retrieved 2 October 2025.
4. "C/2020 A2 (Iwamoto) – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory . Retrieved 1 October 2025.
5. "Observation list for C/2020 A2". COBS – Comet OBServation database. Retrieved 2 October 2025.
6. "New Comet Discovered by Japanese Amateur Astronomer". National Astronomical Observatory of Japan. 14 January 2020. Retrieved 1 October 2025.
7. Q. Z. Ye; G. Sun; et al. (January 2020). D. W. Green (ed.). "Comet C/2020 A2 (Iwamoto)" . Central Bureau for Astronomical Telegrams. 4715 (1). Bibcode:2020CBET.4715....1Y.

External links

• C/2020 A2 at the JPL Small-Body Database
  • Close approach  · Discovery  · Ephemeris  · Orbit viewer  · Orbit parameters  · Physical parameters
• C/2020 A2 at Gideon van Buitenen's website
• C/2020 A2 at Seiichi Yoshida's website
• C/2020 A2 at In-The-Sky.org