Timothy B. Spahr

Last updated
Minor planets discovered: 58 [1]
see § List of discovered minor planets

Timothy Bruce Spahr (born 1970) is an American astronomer and prolific discoverer of minor planets. [2]

Astronomer Scientist who studies celestial bodies

An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets, and galaxies – in either observational or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. Related but distinct subjects like physical cosmology, which studies the Universe as a whole.

Minor planet astronomical object in direct orbit around a star that is neither a planet nor originally classified as a comet

A minor planet is an astronomical object in direct orbit around the Sun that is neither a planet nor exclusively classified as a comet. Before 2006 the International Astronomical Union (IAU) officially used the term minor planet, but during that year's meeting it reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs).


From 2000–2014 he worked at the Harvard-Smithsonian Center for Astrophysics Minor Planet Center. From September 2006 to December 2014 he was the director of Minor Planet Center. He is a co-discoverer of Callirrhoe, a moon of Jupiter, and of Albiorix, a moon of Saturn. He also discovered two periodic comets: 171P/Spahr and P/1998 U4. He is credited by the Minor Planet Center with the discovery of 58 minor planets. [1]

The Minor Planet Center (MPC) is the official worldwide organization in charge of collecting observational data for minor planets, calculating their orbits and publishing this information via the Minor Planet Circulars. Under the auspices of the International Astronomical Union (IAU), it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory.

Callirrhoe (moon) moon of Jupiter

Callirrhoe ( kə-LIRR-o-ee; Greek: Καλλιρρόη), also known as Jupiter XVII, is one of Jupiter's outer natural satellites. It is an irregular moon that orbits in a retrograde direction. Callirrhoe was imaged by Spacewatch at Kitt Peak National Observatory from October 6 through November 4, 1999, and originally designated as asteroid (1999 UX18). It was discovered to be in orbit around Jupiter by Tim Spahr on July 18, 2000, and then given the designation S/1999 J 1. It was the 17th confirmed moon of Jupiter.

Albiorix (moon) moon of Saturn

Albiorix is a prograde irregular satellite of Saturn. It was discovered by Holman and colleagues in 2000, and given the temporary designation S/2000 S 11.

Dr. Spahr is currently the CEO of NEO Sciences LLC, a consulting firm specializing in characterization of Near-Earth Objects (NEOs) including PHAs (Potentially Hazardous Asteroids), Asteroid and Comet science, and planetary defense coordination. Dr. Spahr is the manager of the UN-sanctioned International Asteroid Warning Network (IAWN) and also serves on the advisory council of The Planetary Society where he is the administrator of the Shoemaker NEO Grant program.

Near-Earth object Solar System object whose orbit brings it into proximity with Earth

A near-Earth object (NEO) is any small Solar System body whose orbit brings it to proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). If a NEO's orbit crosses the Earth's, and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO). Most known PHOs and NEOs are asteroids, but a small fraction are comets.

Potentially hazardous object asteroid or comet with an orbit such that it has the potential to make close approaches to the Earth

A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and large enough to cause significant regional damage in the event of impact. They are defined as having a minimum orbital intersection distance with Earth of less than 0.05 astronomical units and an absolute magnitude of 22 or brighter. 98% of the known potentially hazardous objects are not an impact threat over the next 100 years.

Asteroid Minor planet that is not a comet

Asteroids are minor planets, especially of the inner Solar System. Larger asteroids have also been called planetoids. These terms have historically been applied to any astronomical object orbiting the Sun that did not resemble a planet-like disc and was not observed to have characteristics of an active comet such as a tail. As minor planets in the outer Solar System were discovered they were typically found to have volatile-rich surfaces similar to comets. As a result, they were often distinguished from objects found in the main asteroid belt. In this article, the term "asteroid" refers to the minor planets of the inner Solar System including those co-orbital with Jupiter.

The Florian asteroid 2975 Spahr was named after him. [2]

2975 Spahr, provisional designation 1970 AF1, is a bright background asteroid from the Flora region of the inner asteroid belt, approximately 6 kilometers (3.7 miles) in diameter. It was discovered on 8 January 1970, by Russian astronomers Hejno Potter and A. Lokalov at the Cerro El Roble Station near Santiago, Chile. The S- or A-type asteroid has a rotation period of 11.9 hours. It was named for Timothy Spahr, an American astronomer and former director of the Minor Planet Center.

List of discovered minor planets

6534 Carriepeterson 24 February 1995 list
(7200) 1994 NO 8 July 1994 list
7476 Ogilsbie 14 April 1993 list
7605 Cindygraber 21 September 1995 list
(7783) 1994 JD4 May 1994 list
7784 Watterson 5 August 1994 list
7835 Myroncope 16 June 1993 list
7885 Levine 17 May 1993 list
(8404) 1995 AN1 January 1995 list
(8563) 1995 US19 October 1995 list
(8893) 1995 KZ23 May 1995 list
(9772) 1993 MB16 June 1993 list
(9799) 1996 RJ8 September 1996 list
(10187) 1996 JV12 May 1996 list
(10862) 1995 QE226 August 1995 list
11596 Francetic 26 May 1995 list
12008 Kandrup 11 October 1996 list
(12404) 1995 QW331 August 1995 list
(13155) 1995 SB119 September 1995 list
(13617) 1994 YA229 December 1994 list
(14472) 1993 SQ1422 September 1993 list
(16708) 1995 SP121 September 1995 list
17601 Sheldonschafer 19 September 1995 list
17602 Dr. G. 19 September 1995 list
(17609) 1995 UR18 October 1995 list
(17633) 1996 JU11 May 1996 list
(17644) 1996 TW810 October 1996 list
(18513) 1996 TS57 October 1996 list
(21228) 1995 SC20 September 1995 list
(21268) 1996 KL122 May 1996 list
22449 Ottijeff 1 November 1996 list
24827 Maryphil 2 September 1995 list
(26167) 1995 SA118 September 1995 list
(30980) 1995 QU331 August 1995 list
(30981) 1995 SJ425 September 1995 list
(32859) 1993 EL15 March 1993 list
(32896) 1994 NM212 July 1994 list
(37652) 1994 JS14 May 1994 list [A]
(37721) 1996 TX810 October 1996 list
(39646) 1995 SK426 September 1995 list
(43891) 1995 SQ121 September 1995 list
(46678) 1996 TZ812 October 1996 list
(48717) 1996 RR515 September 1996 list
(52471) 1995 SG426 September 1995 list
(52529) 1996 RQ7 September 1996 list
58373 Albertoalonso 19 September 1995 list
(65813) 1996 TT57 October 1996 list
(69405) 1995 SW4830 September 1995 list
(69410) 1995 UB323 October 1995 list
(73762) 1994 LS3 June 1994 list
(85332) 1995 SH429 September 1995 list
96268 Tomcarr 20 September 1995 list
(134372) 1995 SB425 September 1995 list
(136704) 1995 TW13 October 1995 list
(174368) 2002 UR929 October 2002 list
(178338) 1995 UT619 October 1995 list
(189796) 2002 GL27 April 2002 list
(207975) 1996 TY812 October 1996 list
Co-discovery made with:
A C. W. Hergenrother

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  1. 1 2 "Minor Planet Discoverers (by number)". Minor Planet Center. September 4, 2016. Retrieved October 28, 2016.
  2. 1 2 Schmadel, Lutz D. (2007). "(2975) Spahr". Dictionary of Minor Planet Names – (2975) Spahr. Springer Berlin Heidelberg. p. 245. doi:10.1007/978-3-540-29925-7_2976. ISBN   978-3-540-00238-3.