1433 Geramtina

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1433 Geramtina
Discovery [1]
Discovered by E. Delporte
Discovery site Uccle Obs.
Discovery date 30 October 1937
MPC designation (1433) Geramtina
Named after
Sister of Bror Asplind [2]
(Swedish astronomer)
1937 UC · 1951 XH
1967 EH · 1974 TX1
main-belt · (outer)[3]
Gefion[4] · background [5]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 79.92 yr (29,191 days)
Aphelion 3.2757 AU
Perihelion 2.3162 AU
2.7960 AU
Eccentricity 0.1716
4.68 yr (1,708 days)
0° 12m 38.88s / day
Inclination 8.2369°
Physical characteristics
Dimensions 12.687±0.209 km[6]
14.22 km (calculated)[3]
14.574±0.247 km[7]
14 h[8]
0.20 (assumed)[3]
SMASS = S[1][3] · S[9]
11.43±0.23[9] · 11.60[1][3][6][7]

1433 Geramtina, provisional designation 1937 UC, is a stony Gefion asteroid from the central regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle on 30 October 1937.[10]

The asteroid was named "Geramtina" after the sister of Swedish astronomer Bror Asplind. Geramtina has an ordinary chondritic composition and has been considered a candidate for being the parent body of the H chondrites. However, results are inconclusive, and recent HCM analysis suggest that Geramtina is a Gefionian interloper rather than a core member of the family. The asteroid has a tentative rotation period of 14 hours.

Orbit and classification[edit]

Geramtina is a core member of the dynamical Gefion family (516).[4] However, it is a non-family asteroid of the main belt's background population when applying the Hierarchical Clustering Method to its proper orbital elements (synthetic),[5] suggesting that Geramtina is an interloper rather than a core member.

It orbits the Sun in the central main-belt at a distance of 2.3–3.3 AU once every 4 years and 8 months (1,708 days). Its orbit has an eccentricity of 0.17 and an inclination of 8° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Uccle in 1937.[10]

Physical characteristics[edit]

Spectral type[edit]

In the SMASS classification, Geramtina is a common, stony S-type asteroid.[1] The photometric survey by Pan-STARRS has also characterized the asteroid as an S-type.[9]


The spectra of Geramtina together with 4182 Mount Locke have been studies in a mineralogical assessment to test whether these considered core members of the Gefion family might be the source of the L chondrites, a common group of meteorites, due to their dynamical and compositional characteristics.[4] Spectra obtained with the 3-meter NASA IRTF telescope, however, were inconclusive and suggest that Geramtina might as well be a H chondrite rather than an L chondrite, but allows for the determination of a general S(IV) ordinary chondritic composition. The researchers also acknowledged that the Gefion family space has a high abundance of interlopers which needs to be ruled out first.[4]

Rotation period[edit]

In October 2007, a rotational lightcurve of Geramtina was obtained from photometric observations at the National Undergraduate Research Observatory, NURO, in Flagstaff, Arizona. Lightcurve analysis gave a tentative rotation period of 14 hours (monomodal solution) with a brightness amplitude of 0.07 magnitude (U=2-).[8] Alternatively, it has a bimodal period solution of 28 hours, which is considered more likely by the observers, but ignored by the Asteroid Lightcurve Data Base.[3][8]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Geramtina measures 12.687 and 14.574 kilometers in diameter and its surface has an albedo of 0.251 and 0.1910, respectively.[6][7]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo of stony asteroids 0.20 and calculates a diameter of 14.22 kilometers based on an absolute magnitude of 11.6.[3]


This minor planet was named by Swedish astronomer Bror Ansgar Asplind (1890–1954) after his sister. The name "Geramtina" is a constructed name. Bror Asplind computed the orbits of several discoveries made at Uccle Observatory in preparation of the 6th IAU General Assembly in Stockholm in 1938. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 129).[2]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 1433 Geramtina (1937 UC)" (2017-10-01 last obs.). Jet Propulsion Laboratory. Retrieved 26 October 2017. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1433) Geramtina. Springer Berlin Heidelberg. p. 115. ISBN 978-3-540-00238-3. Retrieved 26 October 2017. 
  3. ^ a b c d e f g "LCDB Data for (1433) Geramtina". Asteroid Lightcurve Database (LCDB). Retrieved 26 October 2017. 
  4. ^ a b c d Roberts, V. R.; Gaffey, Michael J.; Fieber-Beyer, Sherry K. (March 2013), Mineralogical Assessment of two Gefion Family Asteroids: 1433 Geramtina and 4182 Mount Locke (PDF), retrieved 26 October 2017 
  5. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 26 October 2017. 
  6. ^ 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:1209.5794Freely accessible. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 26 October 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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 26 October 2017. 
  8. ^ a b c Johnson, Thomas; Pech, Katherin; van Schilfgaarde, Ryan; Chase, Matt; Burns, M. Shane (October 2008). "Lightcurve Analysis of 102 Miriam, 1433 Geramtina, and 2648 Owa". The Minor Planet Bulletin. 35 (4): 151–152. Bibcode:2008MPBu...35..151J. ISSN 1052-8091. Retrieved 26 October 2017. 
  9. ^ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 26 October 2017. 
  10. ^ a b "1433 Geramtina (1937 UC)". Minor Planet Center. Retrieved 26 October 2017. 

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