8661 Ratzinger

8661 Ratzinger
Discovery [1]
Discovered byL. D. Schmadel
F. Börngen
Discovery siteKarl Schwarzschild Obs.
Discovery date14 October 1990
(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 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc49.86 yr (18,213 days)
Aphelion3.1158 AU
Perihelion2.9001 AU
3.0080 AU
5.22 yr (1,906 days)
0° 11m 20.04s / day
Physical characteristics
4.301035±0.000002 h[5]

8661 Ratzinger, provisional designation 1990 TA13, is an Eoan asteroid from the outer region of the asteroid belt, approximately 13.4 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.[7] The asteroid was named after Cardinal Joseph Ratzinger, who became Pope Benedict XVI.[2]

Orbit and classification[]

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.[8]: 23  It orbits the Sun at a distance of 2.9–3.1 AU once every 5 years and 3 months (1,906 days). Its orbit has an eccentricity of 0.04 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.[7]

Physical characteristics[]

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] In 2018, Josef Ďurech et al. measured its rotation period as 4.301035±0.000002 hours and provided a partial shape model.[5]

As of 2020, Ratzinger's composition remains unknown.[1][6]


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)" (2019-08-28 last obs.). Jet Propulsion Laboratory. Archived from the original on 25 December 2019. Retrieved 17 April 2020.
  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 "Asteroid 8661 Ratzinger – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 27 October 2019.
  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 Ďurech, J.; Hanuš, J.; Alí-Lagoa, V. (September 2018). "Asteroid models reconstructed from the Lowell PhotometricDatabase and WISE data". Astronomy & Astrophysics. 617. arXiv:1807.02083. doi:10.1051/0004-6361/201833437. Retrieved 17 April 2020.
  6. ^ a b "LCDB Data for (8661) Ratzinger". Asteroid Lightcurve Database (LCDB). Retrieved 17 April 2020.
  7. ^ a b "8661 Ratzinger (1990 TA13)". Minor Planet Center. Retrieved 4 July 2016.
  8. ^ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 July 2016.

External links[]