Comet discoverers & Comet discoveries by amateurs

2020 - now

Last update:  20. August 2021

Discoveries from 1978 to 1999 Discoveries from 2000 to 2009
Discoveries 2010 to 2019

This page was initially created by Juan José González - José Fernández, written in Spain and can be found at

I used an automatic translation into English and tried to correct it into readable English. Please notice that English is not my native language. Fell free sending me corrections of any kind.

I also used information from the website of Maik Meyer. Giuseppe Pappa (giuseppe.pappa->> added information to the early discoverystories.



Sad news arrived on March 5th. Roy Tucker, discoverer of 2 comets and many asteroids, including 99942 Apophis, passed away at the age of 70 years.

Again, sad news for the Comet community. On August 13th. Carolyn S. Shoemaker discoverer of 32 comets and many more asteroids passed away at the age of 92 years.

Masuyuki IwamotoC/2020 A2 (Iwamoto)

This object was reported on 2020 Jan. 9 UT as a possible comet by M. Iwamoto (872) and it was placed on the PCCP.
It was discovered on two CCD frames taken on Jan. 8.86 UT with a 10-cm Pentax 400-mm-f.l. f/4.0 lens and a Canon EOS 6D camera.

On Jan. 13, G. Borisov (L51) reported this object as having a diffuse 40" coma. Additional reports of cometary features MPEC 2020-A132.

CBET no. 4714, issued on 2020, Jan. 13th. announced the discovery of a new comet. It's the 4th. comet discovery of Masuyuki Iwamoto and 3 within 18 months.

Mr. Masuyuki Iwamoto
Copyrights: Masuyuki Iwamoto + Hoshinavi

Copyright: Michael Jäger, 14.01.2020

Eduardo PimentelC/2020 G1 (Pimentel)

CBET 4754 & MPEC 2020-H06, issued on 2020, April 17, announces the discovery of a new comet (magnitude ~15) by Eduardo Pimentel on CCD images taken by Jacques, Pimentel, and J. Barros with a 0.28-m f/2.2 astrograph of the "Southern Observatory for Near Earth Research" (SONEAR) at Oliveira, Brazil. The new comet has been designated P/2020 G1 (Pimentel).
This is the second comet that takes the name of Eduardo Pimentel. His first discovery was C/2015 Q2.

Story of the discovery as a video (Portuguese)

Discovery telescope 2020G1


SONEAR staff: Joao Ribeiro (left), Eduardo Pimentel (middle), Cristovao Jacques (right)

Leonardo S. Amaral C/2020 O2 (Amaral)

CBET 4822 & MPEC 2020-P10, issued on 2020, August 02, announced the discovery of a comet (magnitude ~18) by Leonardo S. Amaral (Rio de Janeiro, Brazil) on three 60-s CCD exposures taken on July 23 with a 0.3-m f/4 reflector. The new comet was discovered with a 0.3-m f/4 reflector at the Observatório Campo dos Amarais (OCA). This is his first comet discovery.

Gennadii Borisov - C/2020 Q1 (Borisov)

CBET 4836 & MPEC 2020-Q109 announces the discovery of a new comet. The new comet was discovered by G. Borisov on August 17th. on images taken from MARGO (L51) observatory. This is the 10th. discovery by Gennadii Borisov.

Comment from the discoverer:
The comet was detected during a search program in the dawn zone (Plan.png). Tel. D=0.65m, F/1.5, FLI ML9000, FOW 2x2 deg,  exp:  50 sec.
A new diffuse object was discovered at the eighth plate (arrow).

Animation Discovery

Copyright: Genaddii Borisov

Roy A. Tucker (1951 - 2021)

The 2 time comet discoverer Roy A. Tucker died on March 5th. at his home in Tucson.
He discovered many new asteroids, 2 comets 328P/LONEOS-Tucker and C/2004 Tucker Q1 and the "famous" asteroid 99942 Apophis.

Roy Tucker

Alain Maury and Georges Attard - C/2021 J1 (Maury-Attard)

CBET 4972 & MPEC 2021-L11, issued on 2021, June 02, announces the discovery of a new comet (magnitude ~19.0) on CCD images taken by A. Maury and G. Attard on May 09.3 UT with the 0.28-m f/2.2 Rowe-Ackermann Schmidt astrograph at San Pedro de Atacama, Chile in the course of the  MAP (W94) survey.  The new comet has been designated C/2021 J1 (Maury-Attard). This is the first comet discovery for Alain Maury as amateur and the first one for Georges Attard. Alain Maury discovered 3 comets (115P/Maury, C/1988 C1 Maury-Phinney and 198P/ODAS (named after the survey name) as a professional astronomer.

Discovery image, Copyright A. Maury and G. Attard

Discovery telescopes, Copyright A Maury

Gennadii Borisov - C/2021 L3 (Borisov)

CBET 4985 & MPEC 2021-M75 issued on 2021, June 22, announces the discovery of a new comet Borisov on CCD images taken on June 8th. This is his 11th. comet.

Comment from the discoverer: The comet was detected during my new search program "Northern sky survey".  A new star like object it was discovered on three CCD frames taken on June 08.90616 UT (Tel. D=0.65m, F/1.5, FLI ML9000, FOW 2x2 deg,  exp:  300 sec)  in the constellation of Cepheus. The information was sent to the MPC as a new NEO gb00279. Two days later, the stacked images show the cometary shape and the object was moved to PCCP.


2021L3 Animation
Animation for June 08 (discovery images)


The images of the comet from my telescopes (0.5 m , 0.65 m)  and Crimean Observatory - 2.6 meter ( for  comparison)
Copyright Genadii Borisov

Hideo NishimuraC/2021 O1 (Nishimura)

CBET 5004 issued on July 25th. reports the discovery of a new comet, discovered by Hideo Nishimuara, Yuto Japan, on three 15 sec. images taken on July 21st. with a Canon EOS 6D and 200mm f/3.2 lens. The comet shows a 2.5' coma with central condensation and was near comet 8P/Tuttle. This is his second comet discovery. The first was comet C/1994 N1Nakamura-Nishimura-Machholz.

Story from the discoverer. Translation by Shigeki Murakami, discoverer of 2 comets.

On the discovery of C/2021 O1 Nishimura

Hideo Nishimura

Translated by Shigeki Murakami

1. Discoverer

Hideo Nishimura, age 72

Kakegawa City, Shizuoka Prefecture, Japan

2. Site and date

Date and time of shooting: 2021 07 21.78306 (UT), 2021 07 22 3:47 (JST) (1), Exposure time 15 seconds

Observing site: Tea plantation: Gomyo, Kakegawa City, Shizuoka Prefecture, Japan

3. Materials

Camera: CANON EOS 6D, 200mm f/3.2 Telephoto lens
Equatorial mount: Takahashi EM200

4. Summary of the discovery

I have completed a nova hunting session, which is my major target of searching, and I still had an extra time. Then, I conducted a comet hunting session in the northeastern sky, and I was lucky enough to shoot a green glowing comet. I checked the position and I wondered if it was an outburst of 8P Tuttle. However, I found the position was different from that of 8P by some 2°, and reported as it a possible new comet.

5. Discovery course

I concentrated on the visual searching of comet until around 2000, and was able to meet a new comet (2). After that I have come to interest in a nova hunting, and I kept searching spending 90% of my activity for nova hunting and 10% for comet.

It was cloudy at dusk on the day before the discovery, and could not take photos for nova hunting in the Milky Way Galaxy. So, on the day I got up at 1:30a.m. local time and headed for the tea plantation where a quarter-hour of drive from my residence. Most part of the summer Milky Way was in the western sky, and I started shooting the Milky Way at 2:08a.m. up to around the constellation of Cassiopeia.

As there was enough time until the start of the twilight, I began to take photos to search for a comet from the southeastern sky, and put the northeast on the backburner where I photographed the day before at predawn.

At the low altitude the sky grew brighter when the shooting area got close to the northeastern sky, and I hurried to take photos with shorter exposure time. Eventually, I finished the hunting session at 4a.m. leaving some planned area to be searched.

I got home and tried to detect objects that are not in the past images using my PC, among which I checked if there was any new object. I noticed a non-stellar object seemingly having some apparent diameter just before the end of the checking work. I thought that I identified a known comet again, and I confirmed using MP checker but no comet was detected.

To make sure what it was I adjusted the brightness of the image using Photoshop Elements and the green star appeared that is typical for a comet.

I emailed Syuichi Nakano, an Associate of the Central Bureau for Astronomical Telegrams and the Minor Planet Center, in Sumoto, Japan, that reported the object is a new comet without doubt. I calmed down and I confirmed if there were any known comets around the position. I found that 8P Tuttle being brightening was near the possible new comet. Immediately, I told Nakano the fact and he said the predicted position of 8P was different from that of the object of interest by some 2°. I remeasured the position of the possible new comet.

Nakano reported the position to IAU and the new comet had been confirmed.

I think back to the situation with a cool head, and I found I was pretty lucky. If I had taken the photo a little bit earlier, the comet would not have been photographed due to the low altitude from the horizon, i.e., the unadjusted image looked like an overexposure photo taken in the daytime. Conversely, if I had shotten a little later, it would have been disappeared in the twilight.

Note of translator

(1) The beginning of the twilight on the day was 3:09a.m. JST (local time). That meant Nishimura took the photo 38 minutes after the start of the twilight.

(2) Nishimura discovered his first comet in 1994: C/1994 N1 Nakamura-Nishimura-Machholz.

Discovery images. One color, one black/white. The black lines are the power lines in the background of the discoverer. See the image below.

Discovery image b/wDiscovery image

NishimuraNishimura Instruments

Discoverer with his instrument. Copyright Hideo Nishimura

A first image taken by Michael Jäger 2021O1

Carolyn S. Shoemaker (1929 - 2021)

On August 13th., Carolyn S. Shoemaker passed away at the age of 92. She discovered 32 comets and is second on the list of all comet discoverers.


Carolyn Shoemaker: Advice for young women and men who might be interested in astronomy.

CometWatch March 2021 Special with David Levy & Carolyn Shoemaker

Astropedia from 2002: as PDF


Remembering Carolyn Shoemaker, by David Levy as PDF

left: Working at the 18" Schmidt-Telescope on Mt. Palomar, right: 2016


Edgar Wilson Award

  Professional Surveys

Image: LINEAR Program

Siding Spring: Robert McNaught (left) and Gordon Garradd (right) in front of the Uppsala dome and its office (right) in 2003.