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Blink image of the discovery triplet showing 2002 NX57, my first discovery (images by NEAT).

My Asteroid Discoveries 

I search for new asteroids - NEA, Trojan and Main Belt -  since 2004. Currently, I have made almost 70 discoveries, including two NEA's (2005 GG81 and 2015 CA40) and three Jupiter Trojans. Below is some information about my search activities, the projects I am/have been involved with, and a list of discoveries.

In 2004 I started my search for asteroids as a volunteer plate reviewer in the Spacewatch FMO Project (which ended in 2006) and discovered the Amor asteroid 2005 GG81. Around the same time I started my search for Main Belt Asteroids & Trojans in the NEAT archives. Early 2009, after 57 discoveries, I stopped hunting in the NEAT archives.

I am a volunteer in the Piszkéstető (Konkoly, HU) survey for NEA's, comets and Main Belt asteroids since the second half of 2012, resulting in one NEA (2015 CA40) and a number of main belt discoveries. In addition I am finding new Main Belt asteroids by making "remote" use of the telescopes in the SSON network.

I do follow-up on recently discovered NEO's by 'remote' use of the telescopes in the SSON network (e.g. here and
here), as well as additional astrometry on main belt objects we encounter in the Konkoly survey.

A Near Earth Asteroid (NEA) with Spacewatch
(see table I)

Spacewatch ran a public participation program from 2003 to 2006, the now discontinued Spacewatch FMO Project, which I joined in January 2004. On 9 April 2005 I discovered my first NEA in this project, 2005 GG81. The discovery was made together with Jim Scotti and Tim Bressi, who manned the telescope that night. The discovery was announced on 11 April 2005 in MPEC K05G73. Our initial internal designation for the object was SW40LW.

2005 GG81 is an Amor class asteroid of approximately 30 meter wide, which can come to within 0.053 AU of the Earth. Because of its small size, it needs to be close to earth to be detected again. The first occasion when that might be possible, will be near 6 April 2051 (see diagram below), when the asteroid might come as close as 0.09 AU again (compare to 0.06 AU for the discovery encounter in 2005). Perhaps I might live to see that happen.

Orbit of the small Amor asteroid 2005 GG81, which I discovered (with J. Scotti and T. Bressi) in the Spacewatch FMO project on 9 April 2005

Orbit of 2005 GG81

Approaches to Earth for 2005 GG81 in future years

2005 GG81 encounter diagram


A Near Earth Asteroid (NEA) with the Piszkéstető (Konkoly) survey

(see table I) 

On Monday 16 February 2015 I discovered a NEA, 2015 CA40, in images taken by Krisztián Sárneczky on the night of Feb 15-16 with the 0.6-meter Schmidt of MPC 461 Piszkéstető (Konkoly) in Hungary. Our initial designation of this object was SaLa122. The discovery was announced on 17 February 2015 in MPEC K15D10. The story of the discovery is detailed here.

2015 CA40

above: One of the discovery images of 2015 CA40

2015 CA40 is a borderline Amor/Apollo asteroid with perihelion just outside earth orbit at 1.004 AU and aphelion between Mars and Earth at 1.20 AU. With H=24.7 the asteroid is estimated to be about 40 meters wide. It has an orbital inclination of 15.02 degrees and an orbital period of 1.16 years. The MOID is 6 lunar distances (0.0155 AU). On Feb 23-24, 2015 it made a close approach to 6.3 lunar distances. The next similar close approach will be on 23 Feb 2066. 

24 feb 2015 imagery

Above: 2015 CA40 in the morning of 24 Feb 2015 near 9 UT, some 12 hours after closest approach. Images taken overr a 10-minute timespan at 2 minute intervals and 30 second exposure with the 0.61-m F/10 Cassegrain of MPC G68 Sierra Stars Obs. in California, USA

Below: Orbit of 2015 CA40 (orbital position for moment of discovery, Feb 15 2015)

orbit 2015 CA40


Distance of 2015 CA40 to earth for the coming century. Note the close approach in 2066


The Piszkéstető (Konkoly, HU) survey

(see table III)

In the summer of 2012 I joined the
Piszkéstető (Konkoly, HU) asteroid survey of Dr. Krisztián Sárneczky as a volunteer plate reviewer, looking (by visual inspection of the images) for objects that have been missed by the automated plate inspection routines. The survey makes use of the Konkoly Mountain Station (Hungary) 60 cm Schmidt telescope. This work is usually done in the evening hours. My first discoveries in this survey were done during the October 2012 run. In February 2015, I discovered a NEA as part of this survey: 2015 CA40.


Main belt discoveries with the 61-cm SSON (MPC G68) telescope
(see table II)

In 2010 I started to make "remote" use of the MPC G68 SSON 61-cm telescope in California, the MPC 857 Rigel IRT 37-cm telescope in Sonoita, Arizona and more recently the MPC G84 81-cm Mt. Lemon Sky Center Schulman telescope in Arizona. Using these telescopes I regularly do follow up astrometry on recent NEA discoveries. 

In September 2012, I more or less by accident made my first asteroid discovery while "remotely" using these telescopes: 2012 SM58, discovered using the 61-cm telescope of MPC G68 of Sierra Stars Observatory, Markleeberg, CA, USA, while attempting to reocover a NEOCP object. 

In April 2013 I appeared to have discovered 2013 GM21 using the 81-cm Schulman telescope of Mt. Lemon Sky Center (G84) in Arizona, USA. I found it while I was targetting one of our Piszkéstető (Konkoly, HU) survey objects for follow-up astrometry. 2013 GM21 just happened to be in the imaged field as well!

No earlier observations than my Apr 6, 2013, observations of 2013 GM21 were given by the MPC untill the second half of May 2013, when suddenly two sets of two-night observations from 2002 (NEAT) and 2006 (Spacewatch) popped up. At that point, it seems I "lost" the discovery!

2012 SM58 discovery images

Discovery images of 2012 SM58 (MPC G68 SSON 61-cm telescope), 21 Sep 2012

Follow-up 17 Nov G84

Follow-up images from 17 October 2012 (MPC G84 Mt. Lemon 81-cm telescope)


Main belt & Trojan discoveries in NEAT images
(see table IV and table V)

Between 2004 and early 2009 I have found 54 new main belt asteroids plus 3 Jovian Trojans in NEAT archive images. Of these, 41 have now been assigned permanent numbers (38 main belts, 3 Trojans; see list below) and seven have been given names.

The NEAT discoveries were made in archived imagery of NASA's NEAT project, which searches for Near Earth Asteroids. Their imagery contained numerous undiscovered main belt asteroids, missed by the automated plate routines. In the mid-2000's it was a sports to hunt for these faint uncatalogued main belt asteroids in the images. The trick was to obtain enough positions on enough nights to get a designation for them from the IAU Minor Planet Center. This involved finding, astrometrically measuring and following the same object in imagery from multiple nights (see link in section useful information below) untill a linked set of observations spanning several nights was obtained. That sounds easy, but isn't.

The objects discovered were typically in the magnitude +19.5 to +21 class in the discovery images, and typically have (estimated) real sizes near 1-2 km diameter. The Trojans are somewhat larger (up to 7-9 km diameter).

family diagram

My discoveries classified into groups and families (last update 9 March 2013)
note: objects assigned to a family have not been counted into a MB group

My first discovery was 2002 NX57. I discovered it on 27 August 2004 in NEAT archive images from July and August 2002. A number of other discoveries followed, 58 in total. In 2008, I discovered my first Jovian Trojans, a special group of asteroids moving in the orbit of Jupiter, in Jupiter's Lagrange points L4 and L5. A full list of discoveries is given below.

As (due to increased competition form other surveys) it became more and more difficult to find new objects in NEAT imagery, and because my attention shifted to actually timely imaging asteroids myself using "remote" telescopes, I stopped hunting the NEAT archives in 2009.


Discovery credits & discoveries list

My discoveries list now counts over 60 objects. Prior to 2010, a "discovery" meant that you had supplied the MPC with positions for the object at at least two (and preferably more) nights, not too far (i.e. not more than a few days) apart. Single Night detections did not count. Currently, per new MPC rules single night detections do often count as a discovery, provided there is a second detection made that same opposition. This need not necessarily be a detection by the same observatory, project or discoverer!

Below is a list of my discoveries so far, according to the rules applying at the time in question and an additional personal rule that a discovery has to be MPEC-ed for me personally to count. Efemerids and/or orbital elements for these objects can be retrieved here.

I got full formal credits for my discovery of 2005 GG81 while a volunteer plate reviewer with Spacewatch, being listed as an 'observer' in the MPEC. Hence, my Spacewatch discovery is an official discovery. Likewise, my discoveries made while "remotely" using the SSON telecopes and my discoveries with Krisztián Sárneczky as part of the Konkoly survey are official discoveries (albeit provisional, as discovery credits sometimes change when the MPC manages to link the object to earlier detections by other observatories after some time).

With NEAT, it is slightly different. After 2003, formal credits for discoveries in the NEAT archives go to the NEAT team and not to the person finding the object in the NEAT imagery and submitting the linked astrometry (they used to in the past). The personal NEAT 'discovery' count on this page therefore is a semi-official one similar to the habit of SOHO comet hunters.


The NEAT-team has been very willing to go along with naming suggestions for main belt objects I discovered in their data in 2004-2009 now bearing a permanent number. Four got named Miskotte, Neirinck, Rietmeijer and Kürti at my suggestion in 2008, one got named Dubois in 2009 and two got named Jobse and Binford in 2010. The naming citations for these asteroids as published in the Minor Planet Circulars can be read here.

Asteroid (183294) Langbroek

In August 2008, the International Astronomical Union named an asteroid after me: asteroid (183294) Langbroek. Read more about it here.

2012 Dr J. Van der Bilt Prize

In November of 2012, the Royal Dutch Astronomy Association (KNVWS) awarded me their Dr J. Van der Bilt Prize for my work on Asteroids, Meteors and Artificial Satellites. Read more about it here.

As is customary, after the award ceremony at the KNVWS Astrodag in Goirle on November 10, 2012, I performed a lecture on my activities, focussing on my asteroid work. The following YouTube video's below show you this full lecture (each part is about 20 minutes), and are in Dutch, not English:

Video Part I

Video Part II

Video Part III


Useful information

A guide to using the Skymorph NEAT archives for discovery and precovery work can be found here. A follow-up ephemerides page for those who want to do follow-up astrometry on the objects I discovered to help improve their orbits, can be found here.

Acknowledgement is made to Jeff Brower for introducing me to the Spacewatch FMO Project, and especially to Rob Matson for introducing me to the techniques of hunting in the NEAT archives using Skymorph and Astrometrica. I thank Krisztián Sárneczky for involving me in the Konkoly survey, and Stefan Kürti for our continuing and much appreciated cooperation. Astrometry on  asteroids is done with Herbert Raab's excellent  Astrometrica software. I thank the people of NEAT for their cooperation in naming several of the asteroids with a permanent number.


NOTE: Only MPEC-ed discoveries are listed

Table I
Discovery (official) in the MPC 691 Spacewatch Project (Near Earth Asteroid) - with J. Scotti and T. Bressi:

obj.       design.     discovered   MPEC    type     q (AU)    e        MOID (AU)

SW40LW     2005 GG81   09-04-2005   K05G73  Amor     1.0565    0.500    0.053      orbit plot

Discovery (official)
in the MPC 461 Piszkéstető (Konkoly) survey (Near Earth Asteroid) - with Krisztián Sárneczky

obj.       design.     discovered   MPEC    type         q (AU)    e        MOID (AU)

SaLa122    2015 CA40   15-02-2015   K15D10  Amor/Apollo  1.0044    0.091    0.0155  orbit plot

Table II

Discoveries (provisional) using the MPC G68 61-cm SSON telescope (Main Belt asteroids)   2012 - current:


obj.       design.     number name        discovered   MPC        Nts  arc subm.    MPEC    Group

LaMa502    2012 SM58                      21-09-2012   G68         5   21/9-17/10   K12T11  MB IIb



Note: if you find and submitt precovery imagery of the objects above, please let me know via

asteroids |at| langbroek dot org


Table III

Numbered discoveries  with Krisztián Sárneczky, MPC 461 Piszkéstető (Konkoly) survey 

(Main Belt asteroids)  2012 - current :


(note: listed discoveries are provisional and this table will be occasionally revised, with objects removed when links with earlier observations pop up. The final discovery credit for post-2010 discovered objects is now only assigned by the MPC upon permanent numbering and under new rules compared to pre-2010 discoveries. Some asteroids in this table might therefore eventually be assigned to another observatory. Hence these discoveries are provisional only. The asteroids with a permanent number are however ascertained discoveries with discovery credits assigned to Krisztián and me)


obj.       design.     number name        discovered   

SaLa016    2012 UU185  551014 Gorman      18-10-2012  

SaLa068    2013 UZ32   555292 Bakels      31-10-2013

SaLa101    2016 CD144  563318 ten Kate    27-10-2014

Table IV
Discoveries (semi-official) in NEAT archives (Trojan asteroids):

obj.       design.     number name        discovered   disc image  Nts  arc subm.   MPEC    a (AU)

ML023A     2001 SD355  283510             26-11-2008   23-11-2002   10  2001-2002   K08W84  5.16
ML041A     2002 WV27   203865             03-12-2008   24-11-2002   5   16/11-27/12 K08X54  5.20
ML137A     2002 WG29   373820             24-01-2009   22-11-2002   6   2001-2002   K09B61  5.25

Table V
Discoveries (semi-official) in NEAT archives (Main Belt asteroids):

obj.       design.     number name        discovered   disc image  Nts  arc subm.   MPEC    Group

LAMA08     2002 NX57   317367             27-8-2004    14-7-2002    3   14/7-8/8    K04Q59  MB I 

LAMA04     2002 QQ65   213628             26-8-2004    28-8-2002    4   22/7-28/8   K04Q71  MB I 

LAMA27     2002 PU167  132798 Kürti       01-9-2004    8-8-2002     6    4/7-29/8   K04R03  MB IIa

LAMA31     2002 OA26   310723             01-9-2004    27-8-2002    4   18/7-27/8   K04R11  MB IIa

LAMA36     2002 QX65   132820 Miskotte    04-9-2004    17-7-2002    6   17/7-29/8   K04R23  MB IIIa

LAMA32     2002 NY57   258817             02-9-2004    14-7-2002    7    4/7-29/8   K04R26  MB IIIb

LAMA12     2002 QA66   287001             28-8-2004    8-8-2002     3    8/8-26/8   K04R52  MB I

LAMA50/51  2002 PA168  142014 Neirinck    04-10-2004   8-8-2002     4    8/8-29/8   K04T13  MB I

LAMA77     2002 PC168                     14-10-2004   30-8-2002    5   11/8-15/9   K04T71  MB I 

LAMA68     2002 QQ66   215463 Jobse       14-10-2004   30-8-2002    6   23/7-15/9   K04U01  Nysa

LAMA90     2002 QR66   258891             27-10-2004   29-8-2002    4    8/8-29/8   K04U59  Vesta 

LAMA92     2002 QS66   179678 Rietmeijer  28-10-2004   26-8-2002    5    8/8-15/9   K04U59  MB I 

LAMA91     2002 QT66   276204             28-10-2004   29-8-2002    5    8/8-29/8   K04U59  Flora

LAMA95     2002 QK67   213629 Binford     27-11-2004   26-8-2002    4    8/8-29/8   K04W48  MB IIa

LAMA2D     2002 BF32   427496             18-11-2006   21-1-2002    3   20/1-22/1   K06WA3  Maria
ML009A     2002 PN188  234784             19-11-2008   8-8-2002     6   23/7-29/8   K08W84  MB IIb
ML022A     2002 WQ27                      25-11-2008   23-11-2002   4   23/11-27/12 K08W84  MB IIa
ML035A     2002 WR27   313517             30-11-2008   24-11-2002   4   23/11-27/12 K08X17  MB IIb
SM002A     2002 XK118  220256             30-11-2008   10-12-2002   5   16/11-19/1  K08X17  MB I
ML040A     2002 UU76   208930             03-12-2008   31-10-2002   8   2001-2002   K08X40  MB IIb
ML050A     2002 WW27   317585             06-12-2008   24-11-2002   3   24/11-10/12 K08X70  MB IIIb
ML048A     2002 WX27   276388             06-12-2008   24-11-2002   5   31/10-27/12 K08X70  MB IIIb
ML062A     2002 WA28                      10-12-2008   23-11-2002   3   13/11-24/11  MB IIa
ML076A     2002 WB28                      12-12-2008   24-11-2002   3   23/11-10/12 K08X83  MB IIb
ML075A     2002 WC28                      11-12-2008   24-11-2002   3   23/11-10/12 K08X83  MB I
ML079A     2002 UV76                      13-12-2008   30-10-2002   4   30/10-10/12 K08X83  MB IIb
ML080A     2002 WF28   270984             13-12-2008   24-11-2002   4   23/11-27/12 K08Y01  MB I
ML083A     2002 YV36                      14-12-2008   27-12-2002   3   10/12-19/01 K08Y01  MB IIa
ML087A     2002 WL28   377108             16-12-2008   23-11-2002   5   30/10-27/12 K08Y02  MB IIIb
ML091A     2002 WM28   206241 Dubois      16-12-2008   24-11-2002   5   31/10-10/12 K08Y02  Hygiea
ML093A     2002 XG119  238040             16-12-2008   10-12-2002   3   24/11-10/12 K08Y02  MB IIIb
ML097A     2002 WO28                      22-12-2008   24-11-2002   3   24/11-10/12 K08Y47  MB IIIb
ML102A     2002 WP28   287432             06-01-2009   24-11-2002   3   16/11-03/12 K09A40  Hygiea
ML104A     2002 XO119  338371             07-01-2009   10-12-2002   3   24/11-10/12 K09A44  MB IIIa
ML110A     2002 WQ28   287433             09-01-2009   23-11-2002   7   31/10-10/12 K09A57  MB IIIb
ML124A     2002 UY76   215518             14-01-2009   31-10-2002   5   31/10-01/12 K09B32  MB IIb
ML115A     2002 UA77   298232             10-01-2009   31-10-2002   6   31/10-10/12 K09B32  MB IIb
ML122A     2002 WT28                      14-01-2009   22-11-2002   8   31/10-10/12 K09B32  Maria
ML123A     2002 WV28   276389             14-01-2009   22-11-2002   6   31/10-10/12 K09B32  Flora
ML134A     2002 WD29   270985             23-01-2009   22-11-2002   4   31/10-10/12 K09B51  MB I
ML140A     2002 UB77   434180             25-01-2009   31-10-2002   4   31/10-22/11 K09B61  MB I
ML143A     2002 WF29                      25-01-2009   22-11-2002   3   04/11-22/11 K09B61  Hungaria
ML138A     2002 WH29                      24-01-2009   22-11-2002   3   04/11-22/11 K09B61  Hungaria
ML145A     2002 VB143  232352             27-01-2009   12-11-2002   5   31/10-10/12 K09B65  Flora
ML146A     2002 VC143                     27-01-2009   04-11-2002   4   31/10-10/12 K09C20  Gefion

ML147A     2002 VK143  357300             28-01-2009   12-11-2002   5   31/10-22/11 K09C20  MB IIb
ML156A     2002 WP29                      04-02-2009   22-11-2002   3   31/10-22/11 K09C49  MB I
ML160A     2002 WR29   240266             04-02-2009   22-11-2002   3   30/10-22/11 K09C49  MB IIIb
ML169A     2002 WS29   377109             08-02-2009   22-11-2002   6   28/10-10/12 K09C68  MB IIIb
ML170A     2002 WT29                      10-02-2009   22-11-2002   3   04/11-22/11 K09C78  MB I
ML177A     2002 WU29   234963             11-02-2009   22-11-2002   4   04/11-08/12 K09C81  Hygiea
ML183A     2002 WV29   226234             16-02-2009   22-11-2002   5   31/10-08/12 K09D18  Flora
ML184A     2002 WW29                      18-02-2009   22-11-2002   3   04/11-10/12 K09D22  Eunomia

ML201A     2002 WZ29                      22-03-2009   24-11-2002   3   24/11-10/12 K09F67  MB IIa

Page allowing to retrieve Osculating orbital elements and/or search Ephemerides for these objects (source: MPC)

total discoveries (status 14 Sep 2015): 69
total temporary designations: 28
total permanent numbers: 41
named asteroids: 7

Near Earth Asteroids: 2
Jupiter Trojans: 3
Main belt asteroids: 64

Spacewatch discoveries: 1
SSON discoveries: 1 
Piszkéstető (Konkoly) discoveries: 10
NEAT discoveries: 57


- Tables only list MPEC-ed discoveries (i.e. multiple night objects);

- Post-2010 objects (Konkoly survey) with provisional designations are provisional discoveries, as       final discovery credits are assigned only at the time of final numbering;

- SW40LW while participating in the Spacewatch FMO project, with J. Scotti and T. Bressi;

- SaLa objects with Krisztián Sárneczky, as part of the Piszkéstető (Konkoly) survey;

- LAMA04, ML009A together with Rob Matson;
- SM002A together with Stephanie Martin;

- NEAT discoveries were in archive imagery: all the others were in timely near-real-time imagery

Positions of the asteroids I discovered (last updated 10 May 2013)

asteroid positions 10 May 2013

asteroid positions 10 may 2013

External links:

IAU Minor Planet Center (MPC)

List of Minor Planet Names (MPC website)

Discovery credit rules per October 2010 (MPC website)

Recent MPEC's (MPC website)

Minor Planet and Comets Ephemeride service (MPC website)

NASA-JPL Small Body Database browser

The NEAT program's website


The SSON network

The Piszkéstető-Konkoly survey


Stefan Kürti's asteroid website


Herbert Raab's Astrometrica software

text and tables last updated: 14 September 2015
diagrams last updated: 11 May 2013
last change: added two new permanent numbers

Document made with KompoZer