1985 Hopmann, provisional designation 1929 AE, is a carbonaceous asteroid in the outer regions of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 13 January 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.[10] It was later named after astronomer Josef Hopmann.[2]

1985 Hopmann
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date13 January 1929
MPC designation(1985) Hopmann
Named after
Josef Hopmann
(German astronomer)[2]
1929 AE · 1951 CA2
1951 CP · 1952 KE
1964 PJ · 1973 AA4
main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc88.16 yr (32,201 days)
Aphelion3.6021 AU
Perihelion2.6408 AU
3.1214 AU
5.51 yr (2,014 days)
0° 10m 43.32s / day
Physical characteristics
Dimensions35.47 km (derived)[3]
35.51±3.1 km (IRAS:6)[1]
44.33±3.53 km[4]
17.476±0.003 h[5]
17.478±0.004 h[6]
17.4787±0.0001 h[7]
17.480±0.002 h[8]
0.039±0.007 (IRAS:6)[4]
0.0613 (derived)[3]
10.75±0.19[9] · 10.9[1][3] · 10.91[4]

Orbit and classificationEdit

Hopmann is a dark C-type asteroid that orbits the Sun in the outer main-belt at a distance of 2.6–3.6 AU once every 5 years and 6 months (2,014 days). Its orbit has an eccentricity of 0.15 and an inclination of 17° with respect to the ecliptic.[1] The first observation used for the body's observation arc was taken at the discovering observatory on 4 February 1926, or 22 days after its official discovering observation.[10]

Physical characteristicsEdit

According to the survey carried out by the Infrared Astronomical Satellite IRAS, Hopmann measures 35.51 kilometers in diameter.[1] The Collaborative Asteroid Lightcurve Link agrees with the Supplemental IRAS Minor Planet Survey (SIMPS) data and derives an albedo of 0.039 and a diameter of 35.47 kilometers,[3] while observations with NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission gave an albedo of 0.06 and a diameter of 44.33 kilometers.[4]

In January and February 2012, three rotational lightcurves were obtained by Robert Stephens at Santana Observatory (646), California, Josep Maria Aymami at Carmelita Observatory (B20), Barcelona, and Patricia Moravec at Oakley Southern Sky Observatory (E09), Australia. The lightcurves gave a well-defined rotation period of 17.476, 17.478 and 17.480 hours, respectively, with a brightness variation between 0.36 and 0.44 magnitude (U=3/3/3-).[5][6][8] In 2016, a re-modeled lightcurve, constructed from data compiled in the Lowell Photometric Database, also gave a concurring period.[7]


This minor planet was named in memory of German astronomer Josef Hopmann (1890–1975), a director of Vienna Observatory between 1951 and 1962, a productive observer of variable and binary stars, and a participant in the international program to observe near-Earth asteroid 433 Eros in the early 1930s. The lunar crater Hopmann is also named in his honour.[2] The official naming citation was published by the Minor Planet Center on 15 October 1977 (M.P.C. 4237).[11]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 1985 Hopmann (1929 AE)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1985) Hopmann". Dictionary of Minor Planet Names – (1985) Hopmann. Springer Berlin Heidelberg. p. 160. doi:10.1007/978-3-540-29925-7_1986. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1985) Hopmann". Asteroid Lightcurve Database (LCDB). Retrieved 25 October 2016.
  4. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 25 October 2016.
  5. ^ a b Aymami, Josep Maria (July 2012). "CCD Photometry and Lightcurve Analysis of Main-Belt Asteroids 14 Irene 4874 Burke, 1985 Hopmann, 3017 Petrovic, and 3070 Aitken from Observatori Carmelita in Tiana". The Minor Planet Bulletin. 39 (3): 179–181. Bibcode:2012MPBu...39..179A. ISSN 1052-8091. Retrieved 25 October 2016.
  6. ^ a b Moravec, Patricia; Cochren, Joseph; Gerhardt, Michael; Harris, Andrew; Karnemaat, Ryan; Melton, Elizabeth; et al. (October 2012). "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2012 January-April". The Minor Planet Bulletin. 39 (4): 213–216. Bibcode:2012MPBu...39..213M. ISSN 1052-8091. Retrieved 25 October 2016.
  7. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 25 October 2016.
  8. ^ a b Stephens, Robert D. (July 2012). "Asteroids Observed from GMARS and Santana Observatories: 2012 January - March". The Minor Planet Bulletin. 39 (3): 181–183. Bibcode:2012MPBu...39..181S. ISSN 1052-8091. Retrieved 25 October 2016.
  9. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 25 October 2016.
  10. ^ a b "1985 Hopmann (1929 AE)". Minor Planet Center. Retrieved 25 October 2016.
  11. ^ Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.

External linksEdit