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1830 Pogson, provisional designation 1968 HA, is a stony Florian asteroid and an asynchronous binary system from the inner regions of the asteroid belt, approximately 8 kilometers (5 miles) in diameter. It was discovered on 17 April 1968, by Swiss astronomer Paul Wild at the Zimmerwald Observatory near Bern, Switzerland.[1] The S-type asteroid has a rotation period 2.6 of hours.[5] It was named for English astronomer Norman Pogson. The discovery of its 2.5-kilometer sized companion was announced in May 2007.[6][7]

1830 Pogson
Discovery [1]
Discovered byP. Wild
Discovery siteZimmerwald Obs.
Discovery date17 April 1968
MPC designation(1830) Pogson
Named after
Norman Pogson[2]
(English astronomer)
1968 HA · 1926 GW
1929 EE · 1942 EC1
1945 BB · 1953 RE1
1955 FX · 1955 GE
1961 AC · 1969 QM
1971 BJ · 1972 NA1
1972 OC · 1972 OD
main-belt[1][3] · (inner)
Flora[4][5] · binary[5][6][7]
Orbital characteristics[3]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 0
Observation arc92.52 yr (33,794 d)
Aphelion2.3117 AU
Perihelion2.0652 AU
2.1884 AU
3.24 yr (1,182 d)
0° 18m 15.84s / day
Known satellites1 (D: 2.52 km, P: 24.24 h)[5][6][7]
Physical characteristics
Mean diameter
7.710±0.669 km[8][9]
8.284±0.116 km[10]
8.35 km[11]
2.56999±0.00004 h[12]
Tholen = S[4]
SMASS = S[4][5]
B–V = 0.910[4]
U–B = 0.500[4]


Orbit and classificationEdit

According to a HCM-analysis by David Nesvorný, Pogson is a member of the Flora family (402),[4] a giant asteroid clan and the largest family of stony asteroids in the asteroid belt.[5][13] It has also been grouped into the Augusta family (list) by Zappalà, while for Milani and Knežević, who don't recognize the Florian clan as a family, Pogson is a non-family asteroid from the main belt's background population.[14]

It orbits the Sun in the inner asteroid belt at a distance of 2.1–2.3 AU once every 3 years and 3 months (1,182 days; semi-major axis of 2.19 AU). Its orbit has an eccentricity of 0.06 and an inclination of 4° with respect to the ecliptic.[3] The asteroid was first observed as 1926 GW at Simeiz Observatory in April 1926. The body's observation arc begins with its observation as 1929 EE at Heidelberg Observatory in March 1929, or 39 years prior to its official discovery observation at Zimmerwald.[1]


This minor planet was named after English astronomer Norman Pogson (1829–1891), inventor of the modern astronomical magnitude scale. At the Radcliffe and Madras observatories, he discovered eight asteroids, including 42 Isis and 67 Asia. The lunar crater Pogson was also named in his honor.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 4236).[15]

Physical characteristicsEdit

In the Tholen and SMASS classification, Pogson is a common, stony S-type asteroid.[3]

Rotation periodEdit

In April 2007, a rotational lightcurve of Pogson was obtained from photometric observations by an international collaboration of Australian, European and American astronomers, namely, David Higgins , Petr Pravec, Peter Kušnirák, Julian Oey and Donald Pray. Lightcurve analysis gave a rotation period of 2.5702±0.0001 hours with a brightness variation of 0.12 magnitude (U=3).[7] In the following month, a more refined period of 2.56990±0.00004 hours with the same amplitude was measured by Petr Pravec (U=3).[12]

Additional period determinations were made by Melissa Dykhuis and collaborators (2.5698 h) at the Calvin College Observatory (H62) during 2008 (U=2+),[16] and by Pierre Antonini (2.5699 h) and Julian Oey (2.604 h) in March 2013 (U=3-/2).[17][18]


During the photometric observation in 2007, it was also revealed, that Pogson is an asynchronous binary system with a minor-planet moon in its orbit.[7] The mutual eclipse and occultation events showed that the companion, provisionally designated S/2007 (1830) 1, orbits its primary every 24.24 hours.[7][12] Based on a secondary-to-primary diameter ratio of 0.32 or larger, Johnston's archive estimates a diameter of 2.52 kilometers for the satellite, separated by 8 kilometers from its primary.[6]

Diameter and albedoEdit

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Pogson measures between 7.7 and 8.35 kilometers in diameter and its surface has an albedo between 0.2188 and 0.274.[8][9][10][11] The Collaborative Asteroid Lightcurve Link adopts the result from Petr Pravec's revised WISE-data,[11] that is, an albedo of 0.2188 and a diameter of 8.35 kilometers based on an absolute magnitude of 12.659.[5]


  1. ^ a b c d e "1830 Pogson (1968 HA)". Minor Planet Center. Retrieved 7 December 2018.
  2. ^ a b Schmadel, Lutz D. (2007). "(1830) Pogson". Dictionary of Minor Planet Names – (1830) Pogson. Springer Berlin Heidelberg. p. 147. doi:10.1007/978-3-540-29925-7_1831. ISBN 978-3-540-00238-3.
  3. ^ a b c d e "JPL Small-Body Database Browser: 1830 Pogson (1968 HA)" (2018-10-22 last obs.). Jet Propulsion Laboratory. Retrieved 7 December 2018.
  4. ^ a b c d e f "Asteroid 1830 Pogson". Small Bodies Data Ferret. Retrieved 7 December 2018.
  5. ^ a b c d e f g "LCDB Data for (1830) Pogson". Asteroid Lightcurve Database (LCDB). Retrieved 7 December 2018.
  6. ^ a b c d Johnston, Wm. Robert (21 September 2014). "Asteroids with Satellites Database – (1830) Pogson". Johnston's Archive. Retrieved 7 December 2018.
  7. ^ a b c d e f Higgins, D.; Pravec, P.; Kusnirak, P.; Oey, J.; Pray, D. (May 2007). "(1830) Pogson". Central Bureau Electronic Telegrams. 957 (957): 1. Bibcode:2007CBET..957....1H. Retrieved 7 December 2018.
  8. ^ a b c d Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System: EAR-A-COMPIL-5-NEOWISEDIAM-V1.0. Bibcode:2016PDSS..247.....M. Retrieved 7 December 2018.
  9. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
  10. ^ 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. (catalog)
  11. ^ a b c d Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026.
  12. ^ a b c Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kusnirák, P.; Hornoch, K.; et al. (March 2012). "Binary asteroid population. 2. Anisotropic distribution of orbit poles of small, inner main-belt binaries". Icarus. 218 (1): 125–143. Bibcode:2012Icar..218..125P. doi:10.1016/j.icarus.2011.11.026.
  13. ^ 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.
  14. ^ "Asteroid (1830) Pogson – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 4 December 2018.
  15. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 7 December 2018.
  16. ^ Dykhuis, Melissa J.; Molnar, Lawrence A.; Gates, Christopher J.; Gonzales, Joshua A.; Huffman, Jared J.; Maat, Aaron R.; et al. (March 2016). "Efficient spin sense determination of Flora-region asteroids via the epoch method". Icarus. 267: 174–203. Bibcode:2016Icar..267..174D. doi:10.1016/j.icarus.2015.12.021.
  17. ^ Behrend, Raoul. "Asteroids and comets rotation curves – (1830) Pogson". Geneva Observatory. Retrieved 7 December 2018.
  18. ^ Oey, Julian (October 2014). "Lightcurve Analysis of Asteroids from Blue Mountains Observatory in 2013". The Minor Planet Bulletin. 41 (4): 276–281. Bibcode:2014MPBu...41..276O. ISSN 1052-8091.

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