Comet discoverers & Comet discoveries by amateurs

2010 - 2017

Last update:  18. March 2017

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

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 ( added information to the early discoverystories.

The automated professional programs LINEAR, NEAT (discontinued), CSS, LONEOS (discontinued), Spacewatch (North Hemisphere) and Siding Spring (South Hemisphere, discontinued), were responsible for the the majority of comet findings in recent years, besides the carried out ones found on the images of the SOHO spacecraft.

But there are still opportunities for amateur astronomers to find comets, searching visual or with the help of digital cameras (CCD or DSLR).

In 2010, with a total of 157 discoveries, 6 comets were found by amateurs:

It was also the year were the cometary community lost Brian Geoffrey Marsden.

In 2011, with a total of 48 discoveries, 5 comets were found by amateurs:

In 2011, the discoverer of 4 periodic comets, Tom Gehrels passed away.


In 2012 62 new comets were discovered, 8 comets were found by amateurs.


In 2013 65 new comets were discovered. It was a great year for amateurs. 14 new comets were found by amateurs, all with CCD or DSLR cameras.

In 2013, the discoverer of 2 comets, Albert Jones passed away.


In 2014 65 new comets were discovered.
In 2014, the discoverer of 18 comets, William A. Bradfield passed away.
The discoverer of 2 comets, Friedrich Wilhelm Gerber passed away.


In 2015 70 new comets were discovered.


In 2016 only 36 new comets were discovered.

On June 26th. the world lost the discoverer of 4 comets Rolf G. Meier.
The discoverer of 67P/Tschurjumow-Gerassimenko Klim Ivanovich Churyumov passed away on Oct. 15th.
The discoverer of comet C/1980 Y2 Roy Panther died in the week of October 17th to 23rd. at the age of 90.


 David Levy, Wendee Levy, Tom Glinos - P/2010 E2 (Jarnac)

An apparently asteroidal object discovered by D. H. Levy, W. Levy, and T. Glinos on Mar. 9, 2010, using a 64-cm reflector at Jarnac Observatory (Vail) has been found to be cometary after posting on the NEO Confirmation Page. D. Chestnov and A. Novichonok (remotely from Tzec Maun Observatory near Mayhill) and W. H. Ryan and E. V. Ryan (Magdalena Ridge) reported about the cometary appearance of the 18.5m object. The MPC was also able to link observations of the Mt. Lemmon Survey obtained on Feb. 17, 2010. The orbit for comet P/2010 E2 (Jarnac) shows perihelion on Apr. 7, 2010, at about 2.4 AU. The period is about 25.3 years. This is the first amateur discovery in 2010, and the 23rd comet for Levy. (IAUC 9125, MPEC 2010-E64).  (Maik Meyer

Image: Confirmation image

C/2010 F4


[Images: Donald Machholz, next to the telescope used in the discovery, C/2010 F4 in CCD image obtained by Ramon Naves on 27 March at 4h00 UT].

The IAUC 9132 of March 26, 2010 reported the discovery of a new comet made ​​visually by Donald Machholz on March 23rd. with a 0.47 m reflector 77x. with magnitude 11 and a coma of 2 '. The discovery was confirmed on Mar. 26th by itself, at a position indicative of a rapid movement towards the Sun, and later by other observers. Preliminary parabolic orbital elements of C/2010 F4  (Machholz) appeared on MPEC 2010-F88 on the 27th, showing perihelion on April 5th at the distance q = 0.61 AU.
This is the 11th. visual comet discovery for Machholz, who had searched 607 hours since his last discovery C/2004 Q2. Also, this is the first visual comet discovery after 2006. (IAUC 9127 (subscription required). (Maik Meyer

From the comets-ml:

Thanks for all of the kind words about this comet discovery. The search for this comet was typical, I do a bit more than 100 hours a year of visual searching, but the discovery was unusual in that it took three days to get it confirmed.
This is mainly due to the fact that I could not detect certain motion in the 15 minutes that I had the comet on the discovery morning. Then I had bad weather for the next two days. Meanwhile, its rapid motion prevented it from being picked up by others.

Later this weekend I'll be writing a more full story than is on, and by next week you can find it there and download it too. Discoverystory

As you know, the comet is faint, and will not be easy to see in the days ahead.

Take care.

Don Machholz
Colfax, CA

P/2010 R2 (LA SAGRA)

J. Nomen reports that an object, discovered in the course of the La Sagra Sky Survey on Sep. 14, 2010, showed some diffuse appearance, which was later confirmed on Sep. 16. Prediscovery images by La Sagra of Aug. 13, did not show that diffuseness so clearly. After placement on the NEO Confirmation Page P. Birtwhistle (Great Shefford, England), R. Holmes and S. Foglia (Westfield, Illinois) and J. V. Scotti (Spacewatch, USA) confirmed the cometary nature of the 17.5m object. Comet P/2010 R2 (La Sagra) passed perihelion already on June 25, 2010, at about 2.6 AU. The period is about 5.5 years. It seems that this object is one of the so called 'main belt comets'. This is the 4th discovery for the amateur survey La Sagra. (CBET 2459 (subscription required), MPEC 2010-S11)  

Jan Vales - P/2010 H2

, Jan Vales by the 0.60 m telescope of Cichocki of Crni Vrh Observatory
right: P/2010 H2-like asteroidal in Virgo, one of the images in the series of the discovery. The brightest star in the field, TYC 311-1309-1, on the left edge, has magnitude 10.4]

The CBET 2249 of April 17th., 2010 reported the discovery of an asteroidal object with unusually bright appearance, by Jan Vales on CCD images obtained on April 16th. (magnitude 12.6) using a 0.60 m telescope (Crni Vrh Observatory, Slovenia
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On April 19th, the CBET 2253 provided additional information. The object was comet, P/2010 H2 (Vales), confirming the presence of a small elliptical point expansion. The new improved astrometric orbital elements, with the perihelion on April 24th. 2010.
The object would have been approximately in 1976 to a minimum distance of 1.0 AU from Jupiter.

The IAUC 9139 and 9137 of April 25th. provided interesting new data. Yang Bin as reported by Sarid and Gal (University of Hawaii), have achieved results in near-infrared spectrophotometry (0.8 to 2.5 microns) from observations on 20th. and April 22nd. by 3 m IRTF telescope (Infrared Telescope Facility, NASA, Mauna Kea - Hawaii). Both nights were observed two broad absorption bands centered at 1.5 and 2.0 microns, which are consistent with the abundance of water ice grains in the central coma. Additionally, we detected a narrow band at 1.65 microns, which indicated the presence of heavy security crystalline ice. According to these preliminary results, the temperature of ice particles observed is about 100 ± 20 K. Moreover, visual estimates in the days after the outburst provide a magnitude m1 ~ 11.5 (Apr. 22) for expanding a coma diameter ~ 1 '. MPEC 2010-H57 offers improved elliptical orbital elements and ephemeris, with perihelion on March 8th., 2010 at a distance q = 3.1 AU, and P = 7.5 years.

Following a text of Jure Skvarca about the circumstances of discovery:

On images taken by Jan Vales in the course of the Crni Vrh Asteroid and Comet Search program PIKA, on April 16th., 2010, an unusually bright unknown object ( mag. 12.5 ) was automatically detected. The object was near opposition, in an area searched by Catalina Sky Survey ( CSS ) just a day before. As it is not usual to encounter unknown objects of this magnitude in the area recently scanned by sky surveys, a question of its nature naturally appeared. The object was placed on the Near Earth Object Confirmation Page and with the help of observations from other observatories it became apparent very soon that it is about 2 AU away. In case that this was an asteroid (as we would infer from the stellar appearance on the discovery images) this would mean a diameter in the order of 100 km, which is extremely unlikely. The remaining explanation within common knowledge of the Solar system is that it is a cometary outburst of a large magnitude. Recently a similar outburst was experienced by comet 17/P Holmes. This object has triggered massive activity of 40 observatories around the world which contributed altogether 226 observations to the Minor Planet Center ( MPC ). The observers from the CSS confirmed that the object is not visible on their images taken only 15 hours before the discovery. There was a lively debate about the nature of this object on the Minor Planet Mailing List with most plausible explanation that it is a previously unknown comet in outburst. Further observations by several observers showed that the object has a wider profile than nearby stars and Alain Maury detected faint coma on long exposures made from Chile. At 19:25 UT on April 17 the MPC issued an electronic circular MPEC 2010-H12 where the object is designated as a comet P/2010 H2. The orbit is still not very well determined, but most likely it has a semimajor axis of 3.9 AU and eccentricity of 0.2. This is similar to the orbital elements of the asteroids of the Hilda family. This object will undoubtedly be investigated further in the days to come.

Kaoru Ikeya and Shigeki Murakami - P / 2010 V1

(Images: Left, Kaoru Ikeya, right: Shigeki Murakami, with the telescopes used for the discovery)

C/2010 V1 was discovered visually and independently by Kaoru Ikeya (Mori-machi, Shuchi-gun, Shizuoka-ken, Japan; 25 cm reflector telescope at 39x) on November 2nd., 2010, and Shigeki Murakami ( Tohkamachi, Niigata-ken, Japan; reflector at 78x 46 cm) on November 3rd., according to the IAUC 9175 from November 3rd.  

The IAUC 9176 November 4th. provided additional information, and MPEC 2010-V46 parabolic orbital elements by which the comet had passed perihelion on October 18th. at the distance q = 1.7 AU. Visual estimates with binoculars made on November 4th. offered a m1 ~ 7.5.

New astrometry ( MPEC 2 010-W29 ) showed that the comet is of short period, with elliptical orbital elements by which the comet had passed perihelion on October 11th. at the distance q = 1.6 AU, with P = 5.0 years.

An extensive story of the discovery appear on Murakami's page:

P/2010 V1 Virgo, November 14, 2010

[The comet was estimated visually m1 ~ 8.2, with a parabolic point of about 10 'along the major axis. The brightest star in the field is SAO 139129, magnitude 7.7. The galaxy visible on the left edge is NGC 4941, magnitude 12.0. ]

Image taken with a 200 mm telescope + CCD by Michael Jäger

Brian Geoffrey Marsden (1937 - 2010)

2010 November 18th.

Mike Meyer: "It is with great sadness that I have to report the death of Brian G. Marsden, one of the greatest astronomers. Brian was the person who has inspired all my astronomical career and helped me so many times with his helpful, patient and friendly answers to all my questions. Without him I would not have achieved what I have. Brian was always helpful to amateurs and listened and gave advice. I am proud to be a "groupie" as he once described Rainer Kracht, himself and me in regard to our comet groups. I will really miss him..."

The obituary by Gareth Williams.

Leonid Elenin - C / 2010 X1 - P/2011 NO1

C/2010 X1

The CBET 2584 of December 13th., 2010 reported the discovery of a new comet by Leonid Elenin (Lyubertsy, Russia) on CCD images obtained remotely from the ISON-NM Observatory (Mayhill, New Mexico, USA) on December 10th. (19 mag.) with a 0.45 m reflector. It was later confirmed by other observers. The very preliminary parabolic orbital elements and ephemeris appeared on MPEC 2010-X101 , according to which the comet had passed perihelion on April 1st., 2010 at a distance q = 5.2 AU.

Subsequent astrometric orbital elements yielded improved, according to which the comet will pass perihelion on September 10th., 2011, to the interesting short distance q = 0.48 AU.

P/2011 NO1

Amateur astronomers L. Elenin (Lyubertsy) and I. Molotow (Moscow) report their discovery of a new comet on Jul. 7th, 2011, using a remotely controlled 0.45-m astrograph at the ISON-NM observatory near Mayhill (NM, USA). After posting on the NEO Confirmation Page R. Holmes, S. Foglia, and T. Vorobjov (Ashmore), Foglia, P. Miller,
P. Roche, A. Tripp, R. Holmes, R. Miles, L. Buzzi (Faulkes Telescope North), L. Buzzi (Varese), N. Howes, G. Sostero, and E. Guido (Faulkes Telescope South), and H. Sato (Nerpio) confirmed the cometary nature of the 19.5m object. While the object was prepared for announcement by the CBAT it was already announced as asteroid 2011 NO1 by the MPC. The first orbit for the still nameless comet P/2011 NO1 indicated perihelion on already on Jan. 22, 2011, at about 1.2 AU. The period is about 13.1 years. This is Elenin's
second comet discovery. (Maik Meyer

Michael Schwartz - C/2011 K1

Paulo R. Holvorcem (Porto Seguro, Bahia, Brazil) and Michael Schwartz (Patagonia, AZ, USA) report their discovery of a new comet using the Tenagra III astrograph on May 26, 2011. After placement on the NEO Confirmation Page W. H. Ryan and E. V. Ryan (Magdalena Ridge Observatory), L. Buzzi (Varese), and R. Holmes, T. Vorobjov, and S. Foglia (Ashmore) confirmed the cometary nature of the 18.5 m object. The first orbit for comet C/2011 K1 (Schwartz-Holvorcem) shows perihelion on Apr. 19, 2011, at about 3.4 AU. This is the 3rd. comet discovery for Holvorcem. (IAUC 9211 (subscription required),MPEC 2011-L04) (Maik Meyer

Tom Gehrels (1925 - 2011)

July 11th., 2011

In 2011, Professor Tom Gehrels passed away, discoverer of 4 periodic comets (64P/Swift-Gehrels, 78P/Gehrels 2, 82P/Gehrels 3, 90P/Gehrels 1). An article on
Wikipedia describes his live and achievements.
Remembering Tom Gehrels (1925–2011)

Artyom Novichonok and Vladimir Gerke - P/2011 R3

The Russian amateur astronomer Artyom Novichonok reports the discovery of a new comet by Vladimir Gerke and himself on images taken with a 40-cm Ritchey-Chretién reflector located at Ka-Dar observatory (near Nizhniy Arkhyz, Russia). After posting on the NEO Confirmation Page N. Howes, G. Sostero, and E. Guido (remotely using Faulkes Telescope North at Haleakala), G. Hug (Scranton), and T. H. Bressi (Spacewatch) were able to confirm the cometary nature. The first orbit for the 18.5m comet P/2011 R3 (Novichonok) indicated perihelion already on Aug. 23, 2011, at about 3.6 AU. The period is about 10.7 years. (Maik Meyer

Claudine Rinner - P/2011 W2 - C/2012 CH17

Copyright: Claudine Rinner

P/2011 W2 (Rinner): Discovered on 2011 Nov. 28, by Claudine Rinner using a 0.5-m reflector situated at Oukaimeden Observatory, Morocco. 17m, q=2.3 AU, T=2011 Oct. 10, P=10.3 years. CBET 2922, MPEC 2011-W80 (Maik Meyer

C/2012 CH 17: Discovered as an asteroidal object in the course of the Morocco Oukaimeden Sky Survey on 2012 Feb. 7. 18m, q=1.3 AU, T=2012 Sep. 28, CBET 3020, MPEC 2012-C48 (Maik Meyer

C/2011 W3

C/2011 W3 (Lovejoy): Discovered on 2011 Nov. 27, by Terry Lovejoy using a 0.2-m reflector and CCD in the course of his routine comet searching from Thornlands, Australia. This is his third comet discovery. The comet is a member of the Kreutz group but seems intrinsically faint. Thus a bright comet at perihelion or a survival of it seems questionable. The comet will remain a southern hemisphere object close to the sun. At discovery it was at 13m, q=0.005 AU, T=2011 Dec. 16. CBET 2931, MPEC 2011-X16 (Maik Meyer

Copyright: Amy & Sarah Lovejoy

Discovery images. Copyright © 2011 by Terry Lovejoy (Thornlands, Queensland, Australia)

A great site showing the appearance of this Great Comet can be found at

Copyright © 2011 by Vello Tabur (Michelago, New South Wales, Australia)

Manfred Bruenjes - C/2012 C2

Copyright: Manfred Bruenjes

C/2012 C2 (Bruenjes): Discovered on 2012 Feb. 11, by amateur astronomer Manfred Bruenjes (Warrensburg, Missouri, USA). 11.5m,  q=0.8 AU, T=2012 Mar. 12, CBET 3019, MPEC 2012-C44 (Maik Meyer
Details about the discovery can be found on his website.

Discovery image of C/2012 C2

C/2012 B3 (LA SAGRA)
C/2012 B3 (La Sagra): Discovered on 2012 Jan. 29, in the course of the amateur La Sagra survey. 18.5m, q=3.5 AU, T=2011 Nov. 29, 5th comet for La Sagra, CBET 3012,
MPEC 2012-C23.
An apparently asteroidal object discovered on CCD images taken with the 0.45-m f/2.8 reflector at La Sagra, Spain (discovery observations tabulated below) was later noted by Jaime Nomen on La Sagra images taken on Jan. 30.2 to be a possible comet with slight diffuseness. After posting on the Minor Planet Center's NEOCP webpage, other CCD astrometrists have commented on the object's cometary appearance. CBET 3012 (Maik Meyer

A more complete story about the discovery can be found here.

P/2012 NJ (LA SAGRA)
An apparently asteroidal object found on CCD images taken in the course
of the La Sagra survey by S. Sanchez, J. Nomen, M. Hurtado, J. A. Jaume, W. K.
Y. Yeung, P. Rios, F. Serra, and V. Rios with a 0.45-m f/2.8 reflector
(discovery observations tabulated below) has been reported by Gerhard J. Hahn
(Institute of Planetary Research, German Aerospace Center, Berlin) as showing
a 35" tail in p.a. 235 deg on stacked and single images taken by Stefano
Mottola using the 1.23-m telescope on Calar Alto on July 16, 17, and 18 UT.

Vitali Nevski and Artyom Novichonok - C/2012 S1 (ISON)

Amateur discovery by V. Nevski and A. Novichonok in the course of the International Scientific Optical Network (ISON) Survey from near Kislovodsk, Russia, on 2012 Sep. 21. (Maik Meyer

About the discovery...

It was first unstable night after ten ones of hard work. The endless clouds disturbed to look around the sky. That night Artyom and me decided to walk through early discovered asteroids with the most interesting orbits.But the sky became clean literally for half an hour till the dawn and it was decided to launch continious search platform on the border of Twins and Cancer – by chance.After the ending of the series Artyom went to have a rest. And I loaded platform in CoLiTec and remained to wait the processing completion learning earlier discovered astrometry of asteroids. When I started the programme of completing results the first thing I noticed among the third position objects was the bright one with unusual moving. The object was not identified with the MPC base. The unusual thing was rather slow movement relatively to the asteroids of the main zone in this region. At that moment I started to realize that so slow object did not belong to the asteroid zone and could be situated only far away behind Jupiter`s orbit. My heart missed a bit. Is it really a comet? There was nothing to do except disposing astrometry on the site NEOCP for acknowledgement. In the evening I asked Artyom to book the time for observation of the object on the 1.5m telescope of Maidanak
observatory to be sure in the comet nature of the object. Artyom and me looked through old materials,analyzed possible orbits of a new object, by then there appeared some new astrometry points. About 4 o`clock in the morning we saw the pictures – no doubt that it was a comet, classical compact one, 9x11, similar to long-period comets. We immediately sent a message to IAU. We were waiting for results. We were afraid that the object has already been discovered. But the most interesting was that the orbit of the comet started to appear with the introduction of new points of astrometry and the analysis showed perihilion near the Sun, so the brightness of the comet in the maximum could reach the full Moon. Finally on October 24 there was a circular and it was hard to believe that perihilion of the comet was 0,01 a.e. and at the maximum brightness could reach negative dimension and such one that the comet could become quite a comet of the century!

Vitali Nevski

Left: Artyom Novichonok  right: Vitali Nevski
Copyright: Vitali Nevski and Artyom Novichonok

Discovery image of C/2012 S1
Copyright: Vitali Nevski and Artyom Novichonok

Confirmation of cometary activity
Copyright: Vitali Nevski and Artyom Novichonok

P/2012 S2 (LA SAGRA)
Discovered in the course of the amateur La Sagra Sky Survey on 2012 Sep. 23. 18m, q=1.4 AU, T=2012 Aug. 19, P=10.5 years.
CBET 3239, MPEC 2012-S79 (Maik Meyer

Tomas Vorobjov - P/2012 T7 (Vorobjov)

Tomas Vorobjov , Bratislava, Slovak Republic, using remotely a 0.81-m f/7 Ritchey-Chretien reflector located at the Mt. Lemmon SkyCenter.

On three 120-s images via the Sierra Stars Observatory Network in the course of a minor-planet search survey undertaken as part of the International Astronomical Search Collaboration (IASC) school campaigns. After posting on the Minor Planet Center's NEOCP webpage, other observers have commented on the object's cometary appearance. The discovery was announced by the Minor Planet Center on 18 October, three days after the discovery.
Full coverage of the discovery can be found at

Copyright: Tomas Vorobjov

Discovery image of P/2012 T7
Copyright: Tomas Vorobjov

Animation of P/2012 T7
Copyright: Tomas Vorobjov

Paulo Holvorcem - C/2013 D1 (Holvorcem)

CBET 3420 announced the discovery of a new comet by Paulo Holvorcem in the course of a sky survey using a the Tenagra III astrograph. It was discovered a 19.2 mag according to MPEC 2013-D41.

This is the 4th. comet discovery but the first getting his name only. The other discoveries were made the late Charles Juels or recently with Michael Schwartz.

Masuyuki Iwamoto - C/2013 E2 (Iwamoto)

CBET 3439 announced the discovery of a new comet by Masuyuki Iwamoto ( Awa, Tokushima-ken, Japan) on CCD images taken on March 10th and 11th using a 100 mm f/4 lens and a Canon EOS 5D DSLR camera.

Copyright: AstroArts/Hiroshi Ando

Copyright: AstroArts/Hiroshi Ando

Copyright: Masuyuki Iwamoto

C/2013 H1 (LA SAGRA)

Discovered in the course of the amateur La Sagra Sky Survey on 2013 Apr. 19. 18m, coma 15", tail 16", T = 2013 June 1.3726,  q = 2.62 AU, (CBET 3485), MPEC 2013-H27

Gennadii Borisov - C/2013 N4 (Borisov)

Ukrainian amateur astronomer Gennady Borisov discovered a brand new comet on July 8 near the bright star Capella in the constellation Auriga. The comet was confirmed and officially christened C/2013 N4 (Borisov) on July 13. At the time of discovery, Borisov was attending the Russian-Ukrainian “Southern Night” star party in Crimea, Ukraine. He nabbed the comet – his first – using an 8-inch (20-cm) f/1.5  wide field telescope of his own design equipped with a CCD camera.
Telescope: GENON (designed by the discoverer), D=200mm, F=300 mm,  CCD: FLI ML 16803, field 7 x 7 deg.

Copyright: Oleg Bruzgalov

Copyright: Oleg Bruzgalov
Discovery image
Copyright Gennady Borisov
Copyright Gennady Borisov

Terry Lovejoy - C/2013 R1 (Lovejoy)

CBET No. 3649, issued on 2013, September 09th, announced the discovery of a new comet (discovery magnitude ~14.4) by Terry Lovejoy on CCD images obtained with a 20-cm f/2.1 Schmidt-Cassegrain reflector on two nights. The new comet has been designated C/2013 R1 (Lovejoy). It is the 4th. discovery. More information about the discovery circumstances can be found here written by Terry Lovejoy.

In recent months I have been putting a considerable amount of effort into improving my automatic comet detection software. It’s now at the point I am saving a considerable amount of time compared to the old method of blinking frames by eye. So it’s really pleasing to have the software find a new comet, C/2013 R1.
On the morning of September 7 (UT) I did an imaging run consisting of 225 individual fields, with 3 separate exposures on each field. By taking 3 separate exposures of the same field, spaced by a time interval of, in this case 8.5 minutes, allows detection of minor planets and asteroids much easier. In practice objects moving as slowly as 0.2 degrees per day show a small but noticeable shift between the images.
Returning to September 7, all of the fields were processed through the detection software which identified a number of suspects. Although mostly false positives are were found in the form of poorly registered stars, reflections and asteroids but one the suspects located in field number 76, centred on RA 6h 00m Dec -7d 9m, looked very much like a comet. At first I thought this would be one of the existing periodic comet’s, but a quick check in guide showed nothing as well as a check using the online Comet NEO Checker tool on the Minor Planet Center website. A further check against the Digital Sky Survey showed nothing either (sometimes a row of faint stars can give the impression of a moving object if one or more of the stars is not visible in one of the image triplets). Below is the actual image triplet with the suspect in it.
Figure 1 – The “suspect” as imaged at 2:30am, 2:38am and 2:47am local time. Each exposure is 14 seconds
Once it was established there was no existing object was there, it was necessary to rule out reflections from bright stars. I have been fooled by this a couple of times before, luckily never reporting it to CBAT until follow-up observations were performed. Furthermore it was surprising this could be a new comet, since the area was readily accessible to northern hemisphere surveys and amateur comet hunters.
So I extrapolated the position for the following morning at RA 05 59 40 and Dec -06 33 00 and waiting anxiously for that area of sky to get high enough to image. At 1:15 am I fired off a single 30 second exposure and as the image displayed I immediately saw a diffuse object very close to the predicted position. I felt positive I had a new comet, but to be sure I began a sequence of 30 second exposures, and as the images display slowly but surely I could see the object move against the star field. There was now no question about this being a comet, but to be certain it was time for other people to confirm the sighting and an orbit to be determined prior to an official announcement. The orbit is important in determining whether the comet is new, or a lost periodic one being rediscovered. Furthermore CBAT have a strict process to prevent embarrassing mishaps (in the past a number of non-existent comets actually got designations).
After obtaining 3 additional astrometric positions from September 8, I submitted a report to CBAT and soon the NEO Confirmation page was updated to reflect the new object. Thanks to the prompt action of the following stations A79, H36, H47, I39, I47, Sato at I89 and Guido, Howes, Sato, Novichonok, Urbanik, Ligustri at Q62 the comet was quickly confirmed as C/2013 R1 in CBET 3649 issued on September 9.
The prospects for C/2013 R1 are quite favourable as it approaches the earth to 0.4 AU in late November when it will most likely be visible in binoculars from dark skies. Images seem to indicate a larger external coma and that the true brightness is around 2 magnitudes higher than current predictions, so it will be interesting to watch total magnitude estimates as it gets closer to the sun. Perihelion occurs on Christmas day when it will be between the orbit of earth and Venus, but it will have receded to 0.9 AU from the earth which should result in a net fading (but it should also be more condensed then). During this time it will pass close to Comet ISON and it may be possible to photograph both of them together with a short telephoto lens.

Finally here are some summary of statistics for this find:
Parameter Value
Comet Discovery Location Monoceros
Comet Discovery Site E27
Comet Designation C/2013 R1
Discover Date Sep 9.7688, 2013
Comet Altitude at discovery 28
Comet Discovery Magnitude 14
Images taken since last Discovery 70,000
E27 Latitude 27.55 S
E27 Altitude 30m
E27 Clear nights (Jan) typical 3
E27 Clear nights (Aug) typical 10
E27 Annual Rainfall 1200mm
E27 Typical night humidity 60-95%
E27 Sky Brightness range SQM 19.0-20.0 at Zenith
Scope Aperture 20.3 cm F ratio 2.1 T ratio (calculated) 2.9
Camera CCD Kodak 8300 KAF
Field of view 2.44 x 1.83 degrees
Image Scale 5.21 arc secs
Exposure range 10-40 seconds
Software Maxim DL, ASCOM, Source Extractor / Pinpoint

C/2013 R1 : 80 x 30 second exposures, FOV is 33 x 33', North at left. Taken September 10.7, 2013 UT.
Copyright Terry Lovejoy

Albert Jones (1920 - 2013)

On September 11th. the community of comet discoverers lost the discoverer of two comets. Albert Jones passed away at the age of 93. He was a active observer of variable stars and discovered both comets during observing variable stars. His first comet discovery was in 1946 (1946h Jones) , the second in 2000 (C/2000 W1  UTSUNOMIYA-JONES).

Albert Jones with the telescope used for his discovery of comet 2000 W1 (Utsonomiya-Jones).

Michael Schwartz - P/2013 T2 (Schwartz)

CBET No. 3676, issued on 2013, October 22, announces the discovery of a new comet (discovery magnitude ~18.8) by M. Schwartz on CCD images obtained with the 0.41-m f/3.75 Tenagra III astrograph.

Paulo Holvorcem - C/2013 U2 (Holvorcem)

CBET No. 3683 announced the discovery of a new comet (discovery magnitude ~ 19 mag.) by Paulo Holvorcem on CCD images.

Personal communication:
The comet was discovered on images taken with the Tenagra 0.41-m astrograph on 2013 Oct. 23 between 09:59 and 11:01 UT, with the moon being 81% illuminated and near zenith. To avoid excessive moonlight interference, search fields for that night were chosen more than 40 degrees from the moon. One of the search areas was chosen some 13 degrees north of the galactic plane, about 48 degrees from the moon. According to the MPC's sky coverage map, this area had not been searched by other surveys that report their sky coverage for at least two weeks, so it seemed like a promising area to search for comets and NEOs. Images from the search with the Tenagra astrograph are processed for moving objects with SkySift, a real-time image processing pipeline I first developed in 2005 for the wide-field bright comet search with Charles Juels at Fountain Hills (2004-2008). On visually inspecting the small subframes around moving object detections produced by the pipeline, in order to reject false ones, I noticed one detection near the corner of a field (these subframes are contained in the attached zip file). The detection was false, but by coincidence the small ... field of the subframes showed a faint real object which coincided with the false detection in the first image only. I measured the positions and magnitudes of this last object on the subframes, and found out why it had not been automatically detected: due to the not so good seeing and very low signal-to-noise ratio, the measured positions were not very accurate, and did not fit well enough to a uniform motion to satisfy the automated detection criteria. I immediately suspected that it could be a comet, due to its slow motion (0.12 deg/day) and a very slight hint of diffuseness. However, the seeing on the discovery images was not good enough to demonstrate this diffuseness. To clarify this, on the next night (2013 Oct. 24 UT) I took three unfiltered 300-s exposures with the Tenagra 0.81-m telescope. This time seeing was good, and I could clearly see that the object was a comet, with a 6" coma and a 6" tail. I then reported the comet discovery to the CBAT and the MPC. The object was placed on the new Possible Comet Confirmation Page (PCCP), and the cometary nature was confirmed by several astrometrists. It stayed on the PCCP for a week, until enough observations could be collected to provide a reasonably firm estimate of the orbit. It turned out to be a long-period comet with perihelion near the distance of Jupiter. This was the third high perihelion comet found at Tenagra in 2013.

In retrospect it was a very lucky find, coming only 8 days after the discovery with the same telescope of C/2013 T2 (Schwartz).

  C/2013 U2 : discovery images, Size: 1.9 x 2.3 arcminutes.

Copyright Paulo Holvorcem

Gennadii Borisov - C/2013 V2 (Borisov)

Personal communication:

On the night of November 6th I made a deep survey observation in Auriga constellation with my telescope Genon 300/1.5, CCD FLI ML16803, exp 600 sec (usually exp.90-180 sec) (information about the telescope GENON 300/1.5 - non commercial project.
I make these telescopes myself. (The comet C/2013 V3 (Nevski) was discovered with the same telescope).

On the same night I made an animation of the first images and found the new diffuse object (too near to the edge of the frame) After that I finished the survey immediately and started doing a series of that object only. Here are some shots and animation made at the moment of the discovery.

2013 V2 : Discovery images, Copyright Genadii Borrisov

 Vitali Nevski - C/2013 V3 (Nevski)

Vitali Nevski reported the discovery of a comet with a 60" coma on four180-s CCD exposures obtained on Nov. 7, with a 0.2-m f/1.5 reflector (and confirmed with images taken using a 0.4-m f/3 reflector) at the ISON-Kislovodsk observatory near Kislovodsk,Russia.

C/2013 V3: Confirmation image. Copyright Viali Nevski.

Copyright Vitali Nevski

Michel Ory - C/2013 V5 (OUKAIMEDEN)

CBET No. 3713, issued on 2013, November 15, announced the discovery of an apparently asteroidal object (discovery magnitude ~19.4) by Michel Ory on CCD images obtained with a 0.5-m f/3 reflector at the Oukaimeden Observatory, Marrakech. It is his second discovery but the first named after the sky survey at Oukaimeden Observatory. More about his first discovery:  P/2008 Q2, Michel Ory

Copyright Michel Ory

C/2014 A4 (SONEAR)

CBET No. 3783, issued on 2014, January 16, announced the discovery of an apparently asteroidal object (discovery magnitude ~18.1) by Cristovao Jacques, Eduardo Pimentel, and Joao Ribeiro de Barros on CCD images obtained on Jan. 12.0 UT with a 0.45-m f/2.9 reflector of the Southern Observatory for Near Earth Research (SONEAR) at Oliveira, Brazil. The object has been found to show cometary appearance by CCD astrometrists elsewhere and then also by Jacques et al. The new comet has been designated C/2014 A4 (SONEAR). Source.

Story about the circumstances of the discovery:

December and January are the rainy season months in Brazil, but this year has been atypical, so we had 12 clear nights in a row. The C/2014 A4 was discovered on the night of January 12th. There was 85% iluminated moon, and we begun the night surveying some low elongation regions due west. Clouds came and we close the roof. One hour later, the sky was clear again and we begun to work on the region between R.A 5 and 6 hours, and declination -40 and -50, with 180 seconds exposures at 10 minutes intervals. The beginning of  the survey was centralized at dec -40 and as  half of the field was above this declination, we spotted the object at declination -39.6 in a matter of lucky, on the 5th survey field. Since December 18th, we are sending the Sky Coverage  report to the MPC., so our coverage for that day can been easily seen.

I use Skysift, a real-time image processing pipeline software developed by Paulo Holvorcem to detect moving objects, but due to my activities, I could only begin to analyse  the images 12 hours after the end of the night. The object apparently was asteroidal, and I made all the checks, including the NEOCP ratings. The rating was good to send to NEOCP. On the next day, Ernesto Guido emailed me saying that he imaged the object in Australia and it was a little bit elongated. One day more, he confirmed the comet nature using Faulkes South. On the same day I also did 60 x 60s images using the T31 telescope of, and after stacking images, it was clear that it was a comet. After we sending our reports, MPC changed the object S002239 from NEOC to PCCP. More observations were done and the circular was issued on January 16th,

discovery images

Telescope used for the discovery.

SONEAR observatory

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

All images copyright Cristovao Jacques & SONEAR

Cristovao Jacques - C/2014 E2 (Jacques)

CBET No. 3828, issued on 2014, March 14, announced the discovery of a comet (~ magnitude 14.7) on CCD images taken by  C. Jacques, E. Pimentel and J. Barros using a 0.45-m f/2.9 reflector at the SONEAR Observatory near Oliveira, Brazil. The new comet has been designated C/2014 E2 (JACQUES).

Report of the discoverer:
On the night 12-13th March with a 12 day old Moon, we begun our NEO survey in regions close to the western horizon, and near the opposition meridian around declinations -30 and -40.  Moon and thin haze clouds were an excellent source for the formation of many false positives in our detection software. In the middle of the night, I checked the second batch of many detections, then suddenly a bright, fast with a little tail object appears in our blinking session. No doubt it was a comet. The traditional check points were done as well the communication to the MPC and CBAT. The object was posted in NECOP as S002692 . After sending the report I tried to grab more follow-up images as the weather begun to deteriorate. The comet was around magnitude 14.5 according our measurements, but I suspected  it was brighter visually.

As soon as it was overcast, I received a message from  my friend Andrés Chapman, Argentine, mentioned that he was observing the new object and he asked me if I´d like to follow up his work. He shared his  screen and I was able to see his images. The comet was obvious, and it was  the end of a funny night.

discovery images

William A. Bradfield (1927 - 2014)

On June 9th the community of comet discoverers lost one of the most sucessful discoverer of comets. William A. Bradfield passed away at the age of 87. He started searching for comets in 1972 and discovered 18 comets visually. All of his 18 discoveries were credited to him alone. His last discovery was C/2004 F4, which passed the sun quite near. A review of his life as a comet hunter can be found at

Obituary William Bradfield (1928-2014)

His remarkable list of discoveries:
  1. C/1972 E1, discovered on March 12, 1972
  2. C/1974 C1, discovered on February 12, 1974
  3. C/1975 E1, discovered on March 12, 1975
  4. C/1975 V2, discovered on November 11, 1975
  5. C/1976 D1, discovered on February 19, 1976
  6. C/1976 E1, discovered on March 3, 1976
  7. C/1978 C1, discovered on February 4, 1978
  8. C/1978 T3, discovered on October 10, 1978
  9. C/1979 M1, discovered on June 24, 1979
  10. C/1979 Y1, discovered on December 24, 1979
  11. C/1980 Y1, discovered on December 17, 1980
  12. C/1984 A1, discovered on January 7, 1984
  13. C/1987 P1, discovered on August 11, 1987
  14. C/1989 A3, discovered on January 6, 1989
  15. C/1992 B1, discovered on January 31, 1992
  16. C/1992 J2, discovered on May 3, 1992
  17. C/1995 Q1, discovered on August 17, 1995
  18. C/2004 F4, discovered on March 23, 2004

Terry Lovejoy - C/2014 Q2 (Lovejoy)

CBET No. 3934, issued on August 18th. 2014, announced the discovery of a new comet. On August 17th., Terry Lovejoy, Birkdale, Australia discovered his 5th. comet, using a 20cm f/2.1 telescope, equipped with Hyperstar and a QHY9 CCD camera.
More details can be found on his discovery report. Thanks for joining it, Terry.

Image triplet taken by Terry Lovejoy of his comet discovery. The comet moves slightly counterclockwise around the larger fuzzy spot over the time frame. Copyright: Terry Lovejoy

 Gennadii Borisov - C/2014 Q3 (Borisov)

CBET No.. 3936, issued on 2014, August 24th, announced the discovery of a new comet (magnitude ~17) by G. Borisov (Observatory MARGO, Nauchnij). The new comet was found on CCD images obtained with a 0.3-m f/1.5 astrograph telescope, taken on 2014, August 22.02. The new comet has been designated C/2014 Q3 (BORISOV). This is his 3rd. discovery within 13 months ! 

Personal report from the discoverer:
In June I started hunting with my new telescope - GenonMax ( D=300mm, F/D 1.5, FOV 4.8 x 4.8 deg).

August, 22 (01 UT) I detected a diffuse object at the edge of the frame (the edge of the frame, as always :):) ) .
But I had doubts. Fortunately, the object was also detected on the next plaste. ( areas crossed). Exp. 120 sec, Mag 17 R.
I sent the information to the MPC. Two days later, сircular MPEC 2014-Q38 was published.

All images copyright Gennadii Borisov

 Gennadii Borisov - C/2014 R1 (Borisov)

CBET No.. 39XX, issued on 2014, Sept. 6th, announced the discovery of a new comet (magnitude ~16) by G. Borisov (Observatory MARGO, Nauchnij). The new comet was found on CCD images obtained with a 0.3-m f/1.5 astrograph telescope, taken on 2014, Sept. 5th. The new comet has been designated C/2014 R1 (BORISOV). 

Personal report from the discoverer:

Early in the morning September 05 ( 00:10 UT) I found a fairly bright object - 16 mag. in Constellation Cancer. Exp 105 sec. There is no doubt- new comet! And with a short tail !
I send the observations to the MPC ( MPEC 2014-R64).

All images copyright Gennadii Borisov

Friedrich Wilhelm Gerber (1932 - 2014)

On Wednesday October 21st. the German comet discoverer Friedrich Wilhelm Gerber passed away. He discovered several comets during his stay in Argentina in the 1960s. He worked 20 years as pastor near Lucas Gonzalez, Entre Rios. Two comets were named after him as well as 2 other discoverers. 1964 L1 (Tomita-Gerber-Honda) and 1967 M1 (Mitchell-Jones-Gerber). The comets were discovered with small binoculars. He was still an active comet observer especially doing spectroscopic observations of comets. The image shows 3 comet discoverers during a meeting of the German Comet section in 2004. In a personal letter to Maik Meyer he described his 10 discoveries. Due to the remote location and the lack of information only two discoveries were credited to him. He also "discovered" the following comets.

1 Humason 1962 B 1961 f 1962 VIII
2 Ikeya 1 1963 A 1963 a 1963 I
3 Tomita-Gerber-Honda 1964 A 1964 c 1964 VI
4 Ikeya 2 1964 B 1964 1964 VIII
5 Rudnicki 1966 B 1966 g 1967 II
6 Mitchell-Jones-Gerber 1967 C 1967 f 1967 VII
7 Honda 1986 A 1968 c 1968 IX
8 White-Ortiz-Bolelli 1970 B 1970 f 1970 VI
9 Mori-Sato-Fujikawa 1976 A 1975 j 1975
10 West 1976 B 1975 n 1976

Some more details about his life and discoveries can be found here

Michael Jäger - Friedrich Wilhelm Gerber - Sebastian Hönig (Copyright unknown)

 Leonid Elenin - P/2014 X1 (Elenin)

CBET no. 4034, issued on 2014, December 14, announced the discovery of a new comet (magnitude ~18) by Leonid Elenin on three CCD images taken on 2014, December 12 with a 0.4-m f/3 astrograph at the ISON-NM Observatory near Mayhill, NM, USA. The new comet has been designated P/2014 X1 (ELENIN). This is his third discovery.


 Gennadii Borisov - C/2015 D4 (Borisov)

CBET no. 4071, issued on 2015 March 3, announced the discovery of a new comet by Gennadii Borisov on CCD images taken with a 0.3-m f/1.5 astrograph telescope. The new comet has been designated C/2015 D4 (Borisov). This is his fith discovery within 20 months. Great performance !

Personal report of the discoverer:

The confirmation of the comet was not very easy. It often happens with discoveries, especially with comet discoveries. 
The object was found in the morning on February 23. I sent observations in MPC and they were placed on the confirmation page (PCCP).
Several observers did not see the object on the following night.
Because of the bad astrometry the object significantly shifted from the expected position (the problem of my short-focus telescope GenonMax300 / 1.5)
We had bad weather at that time.
It was a clear night only on February 25 and I tried to find almost lost object.
It was not easy but I managed to see the position of an object with a small tail quite far from the ephemeris. It's fantastic: it is a comet and it exists!
More accurate position data of the object allowed other observers to confirm it.

All images copyright Gennadii Borisov

C/2015 F2 (POLONIA)

CBET nr. 4083, issued on 2015, March 26, announces the discovery of a comet (magnitude ~17) by R. Reszelewski, M. Kusiak, M. Gedek and M. Zolnowski on CCD images taken on 2015, March 23 with a remote-controlled 0.1-m f/5 astrograph of the Polonia Observatory at San Pedro de Atacama, Chile, in the course of their comet-search program. The new comet has been designated C/2015 F2 (POLONIA).


Cristovao Jacques - C/2015 F4 (Jacques)

CBET no. 4085, issued on 2015, March 31, announces the discovery of a comet (magnitude ~16) by C. Jacques on CCD images taken on 2015, March 27.2  by C. Jacques, E. Pimentel and J. Barros with a 0.28-m f/2.2 astrograph at the SONEAR Observatory (Oliveira, Brazil).  The new comet has been designated C/2015 F4 (JACQUES). It's his second discovery.


From the discoverer:

March was a rainy month and we could  only observe in two nights. Most of the time our search is dedicated to NEO survey, but we reserve some time to search for comets in low elongations.  At the very end of the night in the last field, we discovered an object of mag. 16.5 using  a 280 mm f/2.2 astrograph. The object seemed fuzzy and with a tiny tail and no doubts it was a comet.
Later, we follow up the discovery with some images in Australia using

Discovery images

Follow up

All images copyright Cristovao Jacques / SONEAR

Eduardo Pimentel - P/2015 Q2 (Pimentel)

CBET no. 4140, issued on 2015, September 02, announced the discovery of a new comet (magnitude ~18.5) by Eduardo Pimentel on Aug. 24.2 UT with a 0.45-m f/2.9 reflector of the SONEAR Observatory at Oliveira. Follow-up observations to confirm the object were obtained by C. Jacques, E. Pimentel, and J. Barros with the same telescope on Aug. 27.3 and 31.3. The new comet has been designated P/2015 Q2 (PIMENTEL). It's the first comet discovery that takes his name.


All images copyright Eduardo Pimentel / SONEAR

Leonid Elenin - C/2015 X4 (Elenin)

CBET nr. 4216, issued on 2015, December 08, announced the discovery of a new comet (magnitude ~18.2) by L. Elenin on three CCD images obtained with a 0.4-m f/3 reflector at the ISON-NM observatory near Mayhill, NM, USA on Dec. 3.5 UT. The new comet has been designated C/2015 X4 (ELENIN). This is his forth discovery.

Rolf G. Meier (1953 - 2016)

Amateur astronomer and comet discoverer Rolf G. Meier (1953–2016) died on June 26th after a short battle with cancer. He was the discoverer of four comets which bear his name (Meier 1978, 1979, 1980, 1984). He received the RASC’s Chant Medal in 1979 for his contributions. Source:

RASC’s Chant Medal

Copyright: Linda Meier

Gennadii Borisov - C/2016 R3 (Borisov)

CBET no. 4321, issued on 2016, September 16, announced the discovery of a new comet (magnitude ~16) by G. Borisov with a 0.3m f/1.5 Genon astrograph. The new comet was found on three unfiltered CCD images ( each 70 seconds). M. Meyer, Limburg, Germany, has suggested similarity of the orbital elements of this comet with those of comet C/1915 R1 (Mellish). Until today, a linkage with the observations from 1915 have failed. This is his 6th. comet discovery.

Comment from the discoverer:
Observations were made on the 30cm, F/1.5  telescope( GenonMax, exposure 70 sec). Potential  object was detected in pictures made 30 minutes before dawn on 11 September.
There were doubts, so I decided to check it on the 50cm, F/1.9 telescope the next night. As soon as I saw this object again, I immediately sent astrometry
of the 1st and the 2nd nights. A 16-magnitude object moved low in the Leo constellation aprox.10-12 degrees above the horizon. This complicated its observation.

Image of the discovery ( Telescope D=300mm,F/1.5, exp 3 x 70 sec), Copyright Gennadii Borisov

Animation from 50 cm, F/1.9  telescope, exp. 120 sec ( next night),Copyright Gennadii Borisov

Klim Churyumov (1937 - 2016)

Copyright: Wikipedia

On Oct. 15th. one of the discoverer of 67P/Tschurjumow-Gerassimenko Klim Ivanovich Churyumov passed away. He discovered 2 comets. More details can be found here.

Roy Panther (1926 - 2016)

Within October 17th to 23rd the discoverer of comet C/1980 Y2 (1980u) Roy Panther passed away at a age of 90. He discovered 1 comet after searching for 33 years. More information can be found at

A video can be found on Youtube.

Copyright Northamptonshire Natural History Society

Leonid Elenin - C/2017 A3 (Elenin)

CBET no. 4344, issued on 2017, January 11th, announced the discovery of a new comet (magnitude ~18) by L.Elenin  with a 0.4m f/2.4 Deltagraph at the ISON-SSO Observatory, Siding Spring on Jan. 5.4 UT. This is his 5th. comet discovery.

Comment from the discoverer:
I'm not a astronomer. I'm programmer and mathematician (work in Institute of Applied Mathematics). It's my hobby and I use my software for remote observations. I spend my money for hosting of two telescopes...

Copyright all images by Leonid Elenin

Joao Ribeiro Barros - C/2017 D2 (Barros)

CBET no. 4366, issued on 2017, March 1st. announced the discovery of a new comet (magnitude ~17.4) by Joao Ribeior Barros. The discovery was made with a 0.45m f/2.9 telescope at the SONEAR Observatory on February 23rd.

Comment from Cristovao Jaques (member of the SONEAR team):
The rainy season in the southeast of Brazil ends on March, but we had a gap of several clear nights in February, that allowed us to continue our survey program (SONEAR) based in finding NEOs in the southern hemisphere. In the night of February 23rd., Joao Ribeiro was the responsible for analysing the candidates of moving objects generated by our survey software called Skysift. On that night, we surveyed a low elongation area located in the constellations of Sagittarius and Telescopium. Joao noticed a small dot moving but he could conclude that it was a comet. After we downloaded  the full frame for the 3 discovery images, he concluded that the object was a comet with a very condensed coma and  prepared the discovery report.

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

Gennadii Borisov - C/2017 E1 (Borisov)

CBET no. 4369, issued on 2017, March 4th. announced the discovery of a new comet (magnitude ~17.4) by Gennadii Borisov. The new comet was detected on three unfiltered 120-s exposures obtained on Mar. 1.10 UT with a 0.4-m f/2.3 astrograph at the "Mobil Astronomical Robotics Genon" Observatory (MARGO) near Nauchnij. This is his 7th. comet discovery.


Hunting in action:

All images copyright Gennadii Borisov

Terry Lovejoy - C/2017 E4 (Lovejoy)

CBET nr. 4373, issued on 2017, March 13, announces the discovery of a new comet (magnitude ~15) by Terry Lovejoy. The new comet was found on  3 CCD images taken each 5 minutes apart on  March 9.68, with a Celestron C14 reflector operating at f/1.9 + QHY9 camera. This is his 6th. discovery.

Interview with Terry Lovejoy.

From the discoverer:

The latest comet, C/2017 E4, was found on a set of 3 images made on the morning of March 10 (Local time) in the constellation of Sagittarius.   Although my 6th discovery, this was the first discovery with the Hyperstar 14" Celestron Schmidt Cassegrain telescope.  However, because the field of view is now smaller I must now make shorter exposures, and more of them, to cover similar amounts of sky as possible.   However, I felt the extra aperture have has more than compensated especially since my location experiences quite bad light pollution being just 18 km from the centre of Brisbane, a city of more than 2 million people.
Back to the comet, it was found using MOD (Moving Object Detection) a computer program I wrote that searches sets of images for moving objects like comets of asteroids.  I tend to run MOD with very high sensitivity, which means it will identify anything remotely resembling a moving object, resulting in mostly false positive detection's.  In fact in crowded star-fields this can be as high as 90% false positives and so  I must examine each detection manually.  Nevertheless, this is huge time saver compared to examining the entire image manually. That morning a lot of the fields were in the milky way I had a large number of false detection's I had to examine, and there were also at least a dozen asteroids, but finally there was one object that had a definite coma and I knew almost certainly a comet.  I then did some checks against known asteroids/comets plus some checks to eliminate internal optical reflections as a cause for the detection.   This all checked out so I was certain of a new comet at this point.
I then sought independent confirmation from another observer, and looking at Messenger I could see Cristavao Jacques in Brazil was online, so I contacted him, but unfortunately dawn had started and he had closed up the observatory so there was no luck there.  I then contacted Michael Mattiazzo and he was able to get a confirmation image not long after from a remote telescope in New Mexico.  This was all well within the 24 hours of the actual discovery images, which is probably a record for me!   The comet was then posted on the Possible Comet Confirmation Page and astrometry started to stream in over the next few days and within 3 days the orbit was known with enough certainty for it to be designated as C/2017 E4.  The orbit indicates - unfortunately - this is an intrinsically small comet that probably stay quite faint (and it could even disappear altogether) but we can always hope for a better display.

Copyright Terry Lovejoy

Copyright Justin Tilbrook


Edgar Wilson Award

  Professional Surveys


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