1101 Clematis

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1101 Clematis
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 22 September 1928
MPC designation (1101) Clematis
Pronunciation /ˈklɛmətɪs/ KLEM-ə-tis[a]
Named after
Clematis (flowering plant)[2]
1928 SJ · 1928 WB
1963 TG1 · 1969 TG1
main-belt · (outer)[1][3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 89.17 yr (32,571 days)
Aphelion 3.4833 AU
Perihelion 2.9770 AU
3.2302 AU
Eccentricity 0.0784
5.81 yr (2,120 days)
0° 10m 11.28s / day
Inclination 21.424°
Physical characteristics
Dimensions 29.13±1.62 km[5]
29.65±1.21 km[6]
33.765±0.809 km[6]
37.60 km (derived)[3]
37.86±1.4 km[7]
6 h[8]
8.5994±0.0006 h[8]
8.61±0.02 h[8]
12.68±0.01 h[9]
34.3±0.1 h[10][b]
0.0788 (derived)[3]
C (assumed)[3]
10.10[5][7] · 10.50[3][6] · 10.6[1] · 10.64±0.28[11]

1101 Clematis, provisional designation 1928 SJ, is an Alauda asteroid from the outermost regions of the asteroid belt, approximately 37 kilometers in diameter. It was discovered on 22 September 1928, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany,[12] and named for the flowering plant Clematis. The presumably carbonaceous asteroid has a relatively long rotation period of 34.3 hours.

Orbit and classification[edit]

Clematis is a member of the Alauda family (902),[4] a large family of typically "bright" carbonaceous asteroids and named after its parent body, 702 Alauda.[13]:23 According to a different study, this object is also the namesake of the Clematis family, a small family of 5–16 asteroids hence they may have arisen from the same collisional event. All members have a relatively high orbital inclination.[14]

It orbits the Sun in the outermost asteroid belt at a distance of 3.0–3.5 AU once every 5 years and 10 months (2,120 days; semi-major axis of 3.23 AU). Its orbit has an eccentricity of 0.08 and an inclination of 21° with respect to the ecliptic.[1]

The body's observation arc begins with its observation as 1963 TG1 at Goethe Link Observatory in October 1963, more than 35 years after its official discovery observation at Heidelberg.[12]

Physical characteristics[edit]

Clematis is an assumed carbonaceous C-type asteroids,[3] while the overall spectral type for members of the Alauda family is that of a somewhat brighter B-type.[13]:23

Rotation period[edit]

In September 2009, a rotational lightcurve[b] of Clematis was obtained from photometric observations by American astronomers Brian Warner at the Palmer Divide Observatory, Colorado, and by Robert Stephens at GMARS (G79, California. Lightcurve analysis gave a synodic rotation period of 34.3 hours with a brightness amplitude of 0.16 magnitude (U=2),[10] which significantly differs from previously reported periods of 6 to 12.68 hours (U=1/2/2/2).[8][9] While not being a slow rotator, Clematis has a much longer period than that known for most other asteroids, and its small amplitude is indicative for a rather spheroidal shape.

Diameter and albedo[edit]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Clematis measures between 29.13 and 37.86 kilometers in diameter and its surface has an albedo between 0.1124 and 0.190.[5][6][7]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0788 and a diameter of 37.60 kilometers based on an absolute magnitude of 10.5.[3]


This minor planet was named after the flowering plant Clematis, a genus within the Ranunculaceae (buttercup or crowfoot family). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H n.a.).[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).[15]


  1. ^ alternatively /kləˈmætɪs/ klə-MAT-iss; or /kləˈmtɪs/ klə-MAY-tis
  2. ^ a b Lightcurve plot of 1101 Clematis, Palmer Divide Observatory, B. D. Warner (2009): rotation period 34.3±0.1 hours with a brightness amplitude of 0.16±0.02 mag. Quality code of 2. Summary figures at the LCDB


  1. ^ a b c d e "JPL Small-Body Database Browser: 1101 Clematis (1928 SJ)" (2017-11-25 last obs.). Jet Propulsion Laboratory. Retrieved 12 January 2018. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1101) Clematis. Springer Berlin Heidelberg. p. 93. ISBN 978-3-540-00238-3. Retrieved 12 January 2018. 
  3. ^ a b c d e f g "LCDB Data for (1101) Clematis". Asteroid Lightcurve Database (LCDB). Retrieved 12 January 2018. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 12 January 2018. 
  5. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 12 January 2018. 
  6. ^ a b c d e 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 12 January 2018. 
  7. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. Bibcode:2004PDSS...12.....T. Archived from the original on 2016-06-03. Retrieved 12 January 2018. 
  8. ^ a b c d Behrend, Raoul. "Asteroids and comets rotation curves – (1101) Clematis". Geneva Observatory. Retrieved 12 January 2018. 
  9. ^ a b Stephens, Robert D. (March 2004). "Photometry of 683 Lanzia, 1101 Clematis, 1499 Pori, 1507 Vaasa, and 3893 DeLaeter". The Minor Planet Bulletin. 31 (1): 4–6. Bibcode:2004MPBu...31....4S. ISSN 1052-8091. Retrieved 12 January 2018. 
  10. ^ a b Warner, Brian D.; Stephens, Robert D. (April 2010). "Analysis of the Lightcurve of 1101 Clematis". The Minor Planet Bulletin. 37 (2): 73–74. Bibcode:2010MPBu...37...73W. ISSN 1052-8091. Retrieved 12 January 2018. 
  11. ^ 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 12 January 2018. 
  12. ^ a b "1101 Clematis (1928 SJ)". Minor Planet Center. Retrieved 12 January 2018. 
  13. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families" (PDF). Asteroids IV: 297–321. arXiv:1502.01628Freely accessible. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. Retrieved 12 January 2018. 
  14. ^ Novaković, Bojan; Cellino, Alberto; Knežević, Zoran (November 2011). "Families among high-inclination asteroids" (PDF). Icarus. 216 (1): 69–81. arXiv:1108.3740Freely accessible. Bibcode:2011Icar..216...69N. doi:10.1016/j.icarus.2011.08.016. Retrieved 12 January 2018. 
  15. ^ 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]