1845 Helewalda

1845 Helewalda
Discovery[1]
Discovered by P. Wild
Discovery site Zimmerwald Obs.
Discovery date 30 October 1972
Designations
MPC designation 1845 Helewalda
Named after
Helen from Wald, Zürich
(school sweetheart)[2]
1972 UC · 1931 VC1
1954 GG · 1971 OR
1971 QX2
main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc 83.61 yr (30,540 days)   
Aphelion 3.1399 AU
Perihelion 2.8014 AU
2.9707 AU
Eccentricity 0.0569
5.12 yr (1,870 days)
54.988°
Inclination 10.720°
142.61°
326.11°
Physical characteristics
Dimensions 20.426±0.147 km[4]
32.03 km (calculated)[3]
7.2786 h[5]
7.399±0.004 h[6]
7.4±0.1 h[7]
7.3985±0.0098 h[8]
0.1289±0.0185[4]
0.057 (assumed)[3]
C[3]
11.2

    1845 Helewalda, provisional designation 1972 UC, is a carbonaceous asteroid in the outer regions of the asteroid belt. It orbits the Sun at a distance of 2.8–3.1 AU once every 5.12 years (1,870 days).[3] The asteroid was discovered by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern on 30 October 1972.[9]

    Helewalda has a well-determined rotation period of 7.4 hours with several photometric measurements taken or evaluated between 2009 and 2015.[5][6][7][8]

    The Light Curve Data Base project calculated the body's diameter to be about 32 kilometers, based on an assumed albedo of 0.057 for a C-type asteroid, while measurements from the NEOWISE mission detected it to be much more reflective and therefore only 20 kilometers in diameter.[3][4]

    The discoverer named a pair of asteroids after two of his former schoolmates, Susi and Helen, both from the small village of Wald, Zürich in Switzerland. This one was dedicated to Helen, while the previously numbered asteroid 1844 Susilva was given to Susi.[2]

    References

    1. 1 2 "JPL Small-Body Database Browser: 1845 Helewalda (1972 UC)" (2015-06-16 last obs.). Jet Propulsion Laboratory. Retrieved November 2015.
    2. 1 2 Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (1845) Helewalda. Springer Berlin Heidelberg. p. 148. ISBN 978-3-540-29925-7. Retrieved November 2015.
    3. 1 2 3 4 5 6 "LCDB Data for (1845) Helewalda". Asteroid Lightcurve Database (LCDB). Retrieved November 2015.
    4. 1 2 3 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. Retrieved November 2015.
    5. 1 2 Roy, René. "Asteroids and comets rotation curves (1845) Helewalda". Geneva Observatory. Retrieved November 2015.
    6. 1 2 Carbo, Landry; Green, Dawson; Kragh, Katherine; Krotz, Jonathan; Meiers, Andrew; Patino, Bernadette; et al. (October 2009). "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2008 October thru 2009 March". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 36 (4): 152–157. Bibcode:2009MPBu...36..152C. ISSN 1052-8091. Retrieved November 2015.
    7. 1 2 Brinsfield, James W. (October 2010). "Asteroid Lightcurve Analysis at the Via Capote Observatory: 2010 February-May". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 37 (4): 146–147. Bibcode:2010MPBu...37..146B. ISSN 1052-8091. Retrieved November 2015.
    8. 1 2 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 November 2015.
    9. "1845 Helewalda (1972 UC)". Minor Planet Center. Retrieved November 2015.

    External links


    This article is issued from Wikipedia - version of the Sunday, January 10, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.