1766 Slipher, provisional designation 1962 RF, is a Paduan asteroid from the central regions of the asteroid belt, approximately 18 kilometers in diameter. It was discovered on 7 September 1962, by astronomers of the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States.[12] The asteroid was named after American astronomers Vesto Slipher and his brother Earl C. Slipher.[2]

1766 Slipher
Discovery [1]
Discovered byIndiana University
(Indiana Asteroid Program)
Discovery siteGoethe Link Obs.
Discovery date7 September 1962
MPC designation(1766) Slipher
Named after
Vesto Slipher and
Earl C. Slipher[2]
1962 RF · 1953 UR
1980 RH5
main-belt · (middle)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc63.04 yr (23,027 days)
Aphelion2.9919 AU
Perihelion2.5066 AU
2.7493 AU
4.56 yr (1,665 days)
0° 12m 58.32s / day
Physical characteristics
Dimensions14.37±3.73 km[4]
14.74±5.05 km[5]
18.959±0.211 km[6]
19.099±0.218 km[7]
20.21 km (calculated)[8]
20.29±1.06 km[9]
7.677±0.0145 h (S)[8][10]
7.693±0.0145 h (R)[10]
0.057 (assumed)[8]
SMASS = C[1] · X[11] · C[8]
11.70[9] · 12.150±0.001 (R)[10] · 12.20[1][4][8] · 12.3[7] · 12.46[5] · 12.75±0.14[11]

Classification and orbitEdit

Slipher is member of the mid-sized Padua family (507), an asteroid family named after 363 Padua and at least 25 million years old. It consists of mostly X-type asteroids, that were previously associated to 110 Lydia (the Padua family is therefor also known as Lydia family).[3][13][14]:23

Slipher orbits the Sun in the central main-belt at a distance of 2.5–3.0 AU once every 4 years and 7 months (1,665 days). Its orbit has an eccentricity of 0.09 and an inclination of 5° with respect to the ecliptic.[1]

The body's observation arc begins with its first identification as 1953 UR at the discovering Goethe Link observatory in October 1953, or 9 years prior to its official discovery observation.[12]

Physical characteristicsEdit

In the SMASS classification, Slipher is a carbonaceous C-type asteroid.[1] PanSTARRS photometric survey characterized the asteroid as an X-type asteroid, which is in line with the overall spectral type of the Padua family.[11][14]:23

Rotation periodEdit

In 2012, two rotational lightcurves of Slipher were obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 7.677 and 7.693 hours with a brightness variation of 0.20 and 0.19 magnitude in the S- and R-band, respectively (U=2/2).[10]

Diameter and albedoEdit

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Slipher measures between 14.37 and 20.29 kilometers in diameter and its surface has an albedo between 0.044 and 0.11.[4][5][6][7][9]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 20.21 kilometers based on an absolute magnitude of 12.2.[8]


This minor planet was named after the brothers Vesto Slipher (1876–1969) and Earl C. Slipher (1883–1964), both graduates of Indiana University. Vesto Slipher was a pioneer investigator of the spectra of the planets, and was the first to measure the redshifts of galaxies, which was instrumental for Hubble's discovery of the expanding Universe. Earl Slipher developed and improved the direct photography of the planets. His photographs are the only continuous and systematic record of the appearance of the planets for a period of more than half a century.[2]

The lunar and Martian Slipher craters were also named after the two brothers.[2] The official naming citation was published by the Minor Planet Center on 20 February 1971 (M.P.C. 3144).[15]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 1766 Slipher (1962 RF)" (2016-11-15 last obs.). Jet Propulsion Laboratory. Retrieved 31 August 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(1766) Slipher". Dictionary of Minor Planet Names – (1766) Slipher. Springer Berlin Heidelberg. p. 141. doi:10.1007/978-3-540-29925-7_1767. ISBN 978-3-540-00238-3.
  3. ^ a b "Asteroid 1766 Slipher – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
  4. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 31 August 2017.
  5. ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 31 August 2017.
  6. ^ 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 31 August 2017.
  7. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  8. ^ a b c d e f "LCDB Data for (1766) Slipher". Asteroid Lightcurve Database (LCDB). Retrieved 31 August 2017.
  9. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
  10. ^ a b c d Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 31 August 2017.
  11. ^ a b c 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 31 August 2017.
  12. ^ a b "1766 Slipher (1962 RF)". Minor Planet Center. Retrieved 31 August 2017.
  13. ^ Carruba, V. (May 2009). "The (not so) peculiar case of the Padua family". Monthly Notices of the Royal Astronomical Society. 395 (1): 358–377. Bibcode:2009MNRAS.395..358C. doi:10.1111/j.1365-2966.2009.14523.x. Retrieved 31 August 2017.
  14. ^ a b 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.
  15. ^ 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