# David J. Tholen

Minor planets discovered: 66 :
* see § List of discovered minor planets
David James Tholen (born 1955) is an American astronomer at the Institute for Astronomy of the University of Hawaiʻi. He holds a 1978 B.S. from the University of Kansas, a 1984 PhD from the University of Arizona, and specializes in planetary and Solar System astronomy. He is a discoverer of minor planets and known for the Tholen spectral classification scheme used on asteroids.

## Professional life

Tholen has discovered a number of asteroids, including the lost 1998 DK36, which may be an Apohele asteroid, and 2004 XZ$_{130}$, which certainly is; in fact, it had the smallest semimajor axis and aphelion distance among the known asteroids (and still holds both records among numbered asteroids as of March 2010). He won the H. C. Urey Prize in 1990.
He co-discovered the asteroid 99942 Apophis (previously known as 2004 MN4). This asteroid will closely approach Earth on April 13, 2029 and very briefly appear as bright as a third magnitude star.
In 1995, Tholen obtained images of the then newly discovered comet Hale-Bopp at a time when the comet was moving very slowly with respect to the background stars, thus permitting the red- green- and blue-filtered images to be combined into a color composite without the background stars appearing as separately colored dots. This color composite image was made publicly accessible via the Institute of Astronomy's web site.
Later, then postdoc at University of Hawaiʻi, Olivier R. Hainaut discovered that a nearly identical image was being discussed by late-night radio host Art Bell and one of his guests, Courtney Brown, who claimed that it proved the existence of an unnatural object following the comet, something supposedly seen by those who had learned how to engage in the technique of "remote viewing". The image provided to Bell by Brown, and eventually made public on Bell's web site, did indeed show an object next to the comet that did not appear in archival images of the sky. In reality, that image had been digitally altered from the original image posted by Tholen, presumably by taking the image of a star near the edge of the frame, adding it next to the comet, and then trimming away the outer edges of the frame.
Tholen and Hainaut exposed the fraud by producing the original image, which showed no such additional object. Nevertheless, some conspiracy theorists maintained that Brown's version was actually the original image and that Tholen had removed the additional object from the one on the Institute's web site. The Heaven's Gate cult was so convinced that the additional object was a spaceship coming to take them away from Earth that they committed mass suicide.
The Mars-crosser asteroid 3255 Tholen, discovered by Edward Bowell in 1980, is named after David Tholen.

## Personal interests

David Tholen and Roy Tucker, co-discovers of 99942 Apophis, are both fans of the TV series Stargate SG-1, which influenced the naming of the asteroid. The show's most persistent villain is "Apophis", an alien also named for the Egyptian god. "We considered a number of names, but 'Apophis' kept floating to the top," says Tucker. "Apophis was a very fitting name for 2004 MN$_4$ not only because of its threatening nature, but also because of its evolution from an Aten asteroid to an Apollo asteroid during the 2029 encounter."
Tholen is a fan of the University of Kansas Jayhawks college basketball team and the Kansas City Royals Major League Baseball team.
He also plays clarinet and bass clarinet for the Honolulu Community Concert Band and the Oahu Community Orchestra.
He is also a user of the OS/2, Linux, Windows, Solaris, and Mac OS operating systems.
Tholen frequently posts to various Usenet groups using the alias tholen@antispam.ham.

## List of discovered minor planets

| 3124 Kansas | 3 November 1981 | list |
| 11606 Almary | 19 October 1995 | list |
| 17045 Markert | 22 March 1999 | list |
| (24978) 1998 HJ151 | 28 April 1998 | list |
| (27002) 1998 DV$_9$ | 23 February 1998 | list |
| 49036 Pelion | 21 August 1998 | list |
| (72912) 2001 OA$_{84}$ | 18 July 2001 | list |
| (96744) 1999 OW$_3$ | 18 July 1999 | list |
| (97725) 2000 GB$_{147}$ | 2 April 2000 | list |
| 99942 Apophis | 19 June 2004 | list |
| (101818) 1999 JD$_{13}$ | 14 May 1999 | list |
| (103501) 2000 AT$_{245}$ | 8 January 2000 | list |
| (124198) 2001 OH$_{77}$ | 18 July 2001 | list |
| (137911) 2000 AB$_{246}$ | 8 January 2000 | list |
| (139478) 2001 OP$_{104}$ | 19 July 2001 | list |
| (141498) 2002 EZ$_{16}$ | 8 March 2002 | list |
| (160848) 2001 BN$_{82}$ | 19 January 2001 | list |
| (164294) 2004 XZ$_{130}$ | 13 December 2004 | list |
| (164405) 2005 UK$_{504}$ | 24 October 2005 | list |
| (164406) 2005 UV$_{504}$ | 24 October 2005 | list |
| (168613) 2000 AA$_{246}$ | 7 January 2000 | list |
| (168828) 2000 SY$_{320}$ | 29 September 2000 | list |
| (190208) 2006 AQ | 2 January 2006 | list |
| (198968) 2005 UF$_{506}$ | 24 October 2005 | list |
| (198971) 2005 UU$_{512}$ | 31 October 2005 | list |
| (202420) 2005 UO$_{506}$ | 24 October 2005 | list |
| (209923) 2005 UX$_{504}$ | 24 October 2005 | list |
| (218017) 2001 XV$_{266}$ | 9 December 2001 | list |
| (229495) 2005 UG$_{508}$ | 24 October 2005 | list |
| (231134) 2005 TU$_{45}$ | 5 October 2005 | list |
| (231199) 2005 UO$_{505}$ | 24 October 2005 | list |
| (231200) 2005 UZ$_{505}$ | 24 October 2005 | list |
| (233166) 2005 UF$_{508}$ | 24 October 2005 | list |
| (238850) 2005 UL$_{530}$ | 24 October 2005 | list |
| (240790) 2005 UH$_{505}$ | 24 October 2005 | list |
| (248508) 2005 UY$_{504}$ | 24 October 2005 | list |
| (250706) 2005 RR$_6$ | 4 September 2005 | list |
| (265742) 2005 UG$_{510}$ | 24 October 2005 | list |
| (268427) 2005 UJ$_{506}$ | 24 October 2005 | list |
| (276891) 2004 RH$_{340}$ | 15 September 2004 | list |
| (277451) 2005 UT$_{504}$ | 24 October 2005 | list |
| (280491) 2004 MO$_7$ | 16 June 2004 | list |
| (280742) 2005 LY$_{42}$ | 8 June 2005 | list |
| (281070) 2006 OY$_{10}$ | 21 July 2006 | list |
| (284133) 2005 UP$_{504}$ | 24 October 2005 | list |
| (290759) 2005 UR$_{505}$ | 24 October 2005 | list |
| (303930) 2005 UZ$_{503}$ | 24 October 2005 | list |
| (306798) 2001 OW$_{94}$ | 20 July 2001 | list |
| (309203) 2007 GG | 7 April 2007 | list |
| (326354) 2000 SJ$_{344}$ | 30 September 2000 | list |
| (327398) 2005 UL$_{505}$ | 24 October 2005 | list |
| (357129) 2001 XU$_{266}$ | 9 December 2001 | list |
| (363071) 2000 GD$_{147}$ | 3 April 2000 | list |
| (363831) 2005 PY$_{16}$ | 1 August 2005 | list |
| (383165) 2005 VJ$_5$ | 7 November 2005 | list |
| (396816) 2004 QU$_{28}$ | 17 August 2004 | list |
| (405762) 2005 YO$_{180}$ | 29 December 2005 | list |
| (437908) 2001 XW$_{266}$ | 9 December 2001 | list |
| (440680) 2005 YW$_{36}$ | 23 December 2005 | list |
| (455951) 2005 UQ$_{504}$ | 24 October 2005 | list |
| (474212) 2000 SH$_{344}$ | 29 September 2000 | list |
| (480852) 2000 WK$_{192}$ | 24 November 2000 | list |
| (481027) 2004 XN$_{44}$ | 13 December 2004 | list |
| (503858) 1998 HQ$_{151}$ | 28 April 1998 | list |
| 541132 Leleākūhonua | 13 October 2015 | list |
| (541152) 2017 EU$_9$ | 24 April 2005 | list |
| Co-discovery made with: $^A$ J. X. Luu $^B$ C. Trujillo $^C$ D. C. Jewitt $^D$ R. J. Whiteley $^E$ R. A. Tucker $^F$ F. Bernardi $^G$ S. S. Sheppard |||