1251 Hedera

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1251 Hedera
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 25 January 1933
MPC designation (1251) Hedera
Named after
Hedera (a.k.a "Ivy")[2]
1933 BE · 1929 CD1
1931 TJ2 · 1975 NW1
A907 GD · A915 CA
main-belt[1][3] · (middle)
background [4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 102.80 yr (37,548 days)
Aphelion 3.1452 AU
Perihelion 2.2884 AU
2.7168 AU
Eccentricity 0.1577
4.48 yr (1,636 days)
0° 13m 12.36s / day
Inclination 6.0489°
Physical characteristics
Dimensions 13.239±0.150 km[5][6]
44.22 km (calculated)[3]
15.015±0.010 h[7]
19.9000±0.0002 h[8]
19.9020±0.0001 h[9]
19.9020±0.0002 h[10]
19.915±0.005 h[11]
19.915±0.007 h[11]
19.985±0.002 h[12]
0.057 (assumed)[3]
Tholen = E[1]
SMASS = X[1]
E[6][13] · C(SDSS-MFB)[3]
B–V = 0.689[1]
U–B = 0.233[1]
10.5[1][3][6] · 10.67±0.28[14]

1251 Hedera, provisional designation 1933 BE, is a background asteroid from the central regions of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 25 January 1933, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany.[15] The asteroid was named for the climbing plant Hedera, commonly known as "ivy".[2]

Orbit and classification[edit]

Hedera is a non-family asteroid from the main belt's background population.[4] It orbits the Sun in the central asteroid belt at a distance of 2.3–3.1 AU once every 4 years and 6 months (1,636 days; semi-major axis of 2.72 AU). Its orbit has an eccentricity of 0.16 and an inclination of 6° with respect to the ecliptic.[1]

The asteroid was first observed as A907 GD at Heidelberg in April 1907. The body's observation arc begins at Heidelberg, the night after its official discovery observation.[15]

Physical characteristics[edit]

Hedera is an E-type and X-type asteroid in the Tholen and SMASS classification, respectively.[1]

Rotation period[edit]

Several rotational lightcurves of Hedera have been obtained from photometric observations since 2007.[7][8][11][12] Best-rated lightcurve by Julian Oey at Kingsgrove and Leura observatories, Australia, gave a rotation period of 19.9000 hours with a consolidated brightness amplitude between 0.41 and 0.61 magnitude (U=3-).[3][8]

Spin axis[edit]

Modeled photometric data from the Lowell Photometric Database (LPD) and the robotic BlueEye600 Observatory, gave a concurring period of 19.9020 hours,[9][10] Both studies determined two spin axes of (124.0°, −70.0°) and (266.0°, −62.0°), as well as (271.0°, −53.0°) and (115.0°, −62.0°) in ecliptic coordinates (λ, β).[9][10]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Hedera measures 13.239 kilometers in diameter and its surface has an albedo of 0.636.[5][6]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and consequently calculates a larger diameter of 44.22 kilometers based on an absolute magnitude of 10.50.[3]


This minor planet was named after the evergreen woody plant Hedera ("ivy") a genus of climbing or ground-creeping woody plants in the aralia family (ivy family). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 115).[2]

Reinmuth's flowers[edit]

Due to his many discoveries, Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between (1009) and (1200). This list also contained a sequence of 28 asteroids, starting with 1054 Forsytia, that were all named after plants, in particular flowering plants (also see list of minor planets named after animals and plants).[16]


  1. ^ a b c d e f g h i j "JPL Small-Body Database Browser: 1251 Hedera (1933 BE)" (2017-11-24 last obs.). Jet Propulsion Laboratory. Retrieved 31 December 2017. 
  2. ^ a b c Schmadel, Lutz D. (2003). "(1251) Hedera". Dictionary of Minor Planet Names – (1251) Hedera. Springer Berlin Heidelberg. p. 104. doi:10.1007/978-3-540-29925-7_1252. ISBN 978-3-540-00238-3. Retrieved 31 December 2017. 
  3. ^ a b c d e f g "LCDB Data for (1251) Hedera". Asteroid Lightcurve Database (LCDB). Retrieved 31 December 2017. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 31 December 2017. 
  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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 31 December 2017. 
  6. ^ a b c d e Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 31 December 2017. 
  7. ^ a b Shevchenko, V. G.; Krugly, Yu. N.; Chiorny, V. G.; Belskaya, I. N.; Gaftonyuk, N. M. (August 2003). "Rotation and photometric properties of E-type asteroids". Planetary and Space Science. 51 (9–10): 525–532. Bibcode:2003P&SS...51..525S. doi:10.1016/S0032-0633(03)00076-X. Retrieved 31 December 2017. 
  8. ^ a b c Oey, Julian (September 2008). "Lightcurve Analysis of Asteroids from the Kingsgrove and Leura Observatories in the 2nd Half of 2007". The Minor Planet Bulletin. 35 (3): 132–135. Bibcode:2008MPBu...35..132O. ISSN 1052-8091. Retrieved 31 December 2017. 
  9. ^ a b c Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909Freely accessible. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 31 December 2017. 
  10. ^ a b c Durech, Josef; Hanus, Josef; Broz, Miroslav; Lehky, Martin; Behrend, Raoul; Antonini, Pierre; et al. (July 2017). "Shape models of asteroids based on lightcurve observations with BlueEye600 robotic observatory". arXiv:1707.03637Freely accessible [astro-ph.IM]. 
  11. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (1251) Hedera". Geneva Observatory. Retrieved 31 December 2017. 
  12. ^ a b Chiorny, V. G.; Shevchenko, V. G.; Krugly, Yu. N.; Velichko, F. P.; Gaftonyuk, N. M. (May 2007). "Photometry of asteroids: Lightcurves of 24 asteroids obtained in 1993 2005". Planetary and Space Science. 55 (7–8): 986–997. Bibcode:2007P&SS...55..986C. doi:10.1016/j.pss.2007.01.001. Retrieved 31 December 2017. 
  13. ^ Belskaya, I. N.; Fornasier, S.; Tozzi, G. P.; Gil-Hutton, R.; Cellino, A.; Antonyuk, K.; et al. (March 2017). "Refining the asteroid taxonomy by polarimetric observations". Icarus. 284: 30–42. Bibcode:2017Icar..284...30B. doi:10.1016/j.icarus.2016.11.003. Retrieved 31 December 2017. 
  14. ^ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 31 December 2017. 
  15. ^ a b "1251 Hedera (1933 BE)". Minor Planet Center. Retrieved 31 December 2017. 
  16. ^ Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1054) Forsytia. Springer Berlin Heidelberg. p. 90. ISBN 978-3-540-00238-3. Archived from the original on 24 September 2017. Retrieved 27 January 2018. 

External links[edit]