1778 Alfvén

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1778 Alfvén
Discovery [1]
Discovered byC. J. van Houten
I. van Houten-G.
Tom Gehrels
Discovery sitePalomar Obs.
Discovery date26 September 1960
MPC designation(1778) Alfvén
Named after
Hannes Alfvén (physicist)[2]
4506 P-L · 1936 HK
1952 DD1 · 1958 FB
1959 NN
main-belt · Themis [3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc62.42 yr (22,800 days)
Aphelion3.5502 AU
Perihelion2.7453 AU
3.1477 AU
5.58 yr (2,040 days)
0° 10m 35.4s / day
Physical characteristics
Dimensions20.51 km (calculated)[3]
20.623±0.240 km[4][5]
4.8050±0.0027 h[6]
4.82±0.05 h[7]
0.08 (assumed)[3]
11.59±0.15 (R)[7] · 11.6[4] · 11.725±0.003 (R)[6] 11.8[1][3] · 12.32±0.54[8]

1778 Alfvén, also designated 4506 P-L, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 20 kilometers in diameter.

It was discovered on 26 September 1960, by astronomers Cornelis van Houten, Ingrid van Houten-Groeneveld and Tom Gehrels at the U.S. Palomar Observatory, in California.[9] It was later named after Swedish Nobelist Hannes Alfvén.[2]

Orbit and classification[edit]

The dark C-type asteroid is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits. Alfvén orbits the Sun in the outer main-belt at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,040 days). Its orbit has an eccentricity of 0.13 and an inclination of 2° with respect to the ecliptic.[1]

A first precovery was taken at Lowell Observatory in 1909. Its first used observation was also a precovery taken at Palomar Observatory in 1954, extending the body's observation arc by 6 years prior to its official discovery observation.[9]

Physical characteristics[edit]

Rotation period[edit]

In February 2013, two rotational lightcurves of Alfvén were obtained from analysis at the Palomar Transient Factory in California. The lightcurves gave a rotation period of 4.82 and 4.8050 hours with a brightness variation of 0.40 and 0.36 magnitude, respectively (U=3-/2).[7][6]

Diameter and albedo[edit]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Alfvén measures 20.62 kilometers in diameter and its surface has an albedo of 0.095,[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 20.51 kilometers with an absolute magnitude of 11.8.[3]

Survey designation[edit]

The survey designation "P-L" stands for Palomar–Leiden, named after Palomar Observatory and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets.[10]


This minor planet was named after Swedish engineer, physicist and Nobel prize winner, Hannes Alfvén (1908–1995).[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3643).[11]


  1. ^ a b c d "JPL Small-Body Database Browser: 1778 Alfven (4506 P-L)" (2017-01-28 last obs.). Jet Propulsion Laboratory. Retrieved 1 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1778) Alfvén". Dictionary of Minor Planet Names – (1778) Alfvén. Springer Berlin Heidelberg. p. 142. doi:10.1007/978-3-540-29925-7_1779. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1778) Alfvén". Asteroid Lightcurve Database (LCDB). Retrieved 19 December 2016.
  4. ^ 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.
  5. ^ 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 20 December 2016.
  6. ^ a b c 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 19 December 2016.
  7. ^ a b c Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; et al. (June 2014). "313 New Asteroid Rotation Periods from Palomar Transient Factory Observations". The Astrophysical Journal. 788 (1): 21. arXiv:1405.1144. Bibcode:2014ApJ...788...17C. doi:10.1088/0004-637X/788/1/17. Retrieved 19 December 2016.
  8. ^ 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 19 December 2016.
  9. ^ a b "1778 Alfven (4506 P-L)". Minor Planet Center. Retrieved 19 December 2016.
  10. ^ "Minor Planet Discoverers". Minor Planet Center. 24 April 2016. Retrieved 19 December 2016.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 December 2016.

External links[edit]