Open main menu

8661 Ratzinger, provisional designation 1990 TA13, is an Eoan asteroid from the outer region of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 14 October 1990, by German astronomers Lutz Schmadel and Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, eastern Germany.[6] The asteroid was named after Cardinal Joseph Ratzinger, who became Pope Benedict XVI.[2]

8661 Ratzinger
Discovery [1]
Discovered byL. D. Schmadel
F. Börngen
Discovery siteKarl Schwarzschild Obs.
Discovery date14 October 1990
MPC designation(8661) Ratzinger
Named after
Pope Benedict XVI
(Pope, chronology)[2]
1990 TA13 · 1969 US
1974 TM1 · 1992 CB1
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc47.45 yr (17,331 days)
Aphelion3.1092 AU
Perihelion2.9004 AU
3.0048 AU
5.21 yr (1,903 days)
0° 11m 21.12s / day
Physical characteristics
20 km (calc. at 0.05)[5]


Orbit and classificationEdit

Ratzinger is a member of the Eos family (606),[3] the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids.[7]:23 It orbits the Sun at a distance of 2.9–3.1 AU once every 5 years and 3 months (1,903 days). Its orbit has an eccentricity of 0.03 and an inclination of 11° with respect to the ecliptic.[1]

In October 1969, it was first identified as 1969 US at Crimea–Nauchnij. The body's observation arc begins at Leoncito in 1974, when it was identified as 1974 TM1, 16 years prior to its official discovery observation at Tautenburg.[6]

Physical characteristicsEdit

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ratzinger measures 13.4 kilometers in diameter and its surface has an albedo of 0.09,[4] while a generic estimate based on its absolute magnitude of 12.3 and a typical carbonaceous albedo of 0.05, gives a diameter of approximately 20 kilometers.[5]

As of 2017, Ratzinger's composition, rotation period and shape remains unknown.[1][8]


This minor planet was named after German Joseph Ratzinger (born 1927), then Cardinal and professor of theology, for the role he played in supervising the opening of the Vatican Secret Archives in 1998 to researchers investigating judicial errors against Galileo, after whom the minor planet 697 Galilea is named, and other medieval scientists.[2]

Ratzinger was considered to be one of the most authoritative voices in the Vatican and became Pope Benedict XVI in 2005. The name was proposed by the asteroid's first discoverer, Lutz Schmadel.[2] The approved naming citation was published by the Minor Planet Center on 23 May 2000 (M.P.C. 40702).[9]


  1. ^ a b c d e "JPL Small-Body Database Browser: 8661 Ratzinger (1990 TA13)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(8661) Ratzinger". Dictionary of Minor Planet Names – (8661) Ratzinger. Springer Berlin Heidelberg. p. 659. doi:10.1007/978-3-540-29925-7_7136. ISBN 978-3-540-00238-3.
  3. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 23 November 2017.
  4. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 4 December 2016.
  5. ^ a b "Absolute Magnitude (H)". NASA/JPL. Retrieved 5 August 2016.
  6. ^ a b "8661 Ratzinger (1990 TA13)". Minor Planet Center. Retrieved 4 July 2016.
  7. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  8. ^ "LCDB Data for (8661) Ratzinger". Asteroid Lightcurve Database (LCDB). Retrieved 22 June 2017.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 July 2016.

External linksEdit