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Call for Observations

Slow Rotating Asteroids, Slow Rotators

Astronomical Observatory Institute of Poznan, Poland is coordinating a world-wide observing campaign for slow rotating asteroids. These are small bodies of the main belt with slow rotation and small lightcurve amplitudes, avoided by most of previous studies [1]. The aim is to improve biased statistics of spin and shape modelled asteroids. Recent results from TESS spacecraft have shown that slow rotators are actually dominating in the population of main belt asteroids [4], while asteroids with available spin and shape model have predominantly short rotation periods.

We focus on multi-apparition photometric observations, lightcurve inversion modelling, and scaling those models with thermal infrared data [2, 3]. However, many of these asteroids have poor or problematic thermal datasets, and cannot be precisely scaled this way. This is where good, multi-chord occultation can greatly help. Occultations can also pinpoint the correct spin and shape solution from two mirror ones produced by lightcurve inversion (see e.g. Svea model fitting in paper [2]). For some of our targets, marked in bold in the list, Gaia mission will provide mass, so precise density could be derived for studies on internal composition.

Please join the project and observe stellar occultations by the these asteroids, whenever possible. In OccultWatcher you can find these objects under the tag "slow rotators".

List of proposed asteroids

  49 Pales                 554 Peraga   
  57 Mnemosyne             581 Tauntonia  	        	     	
 101 Helena                               	
 144 Vibilia               668 Dora                   
 185 Eunike                672 Astarte                
 200 Dynamene              688 Melanie                
 215 Oenone                777 Gutemberga  
 248 Lameia                814 Tauris   
 269 Justitia              833 Monica   
 279 Thule                 838 Seraphina                                   
 305 Gordonia              845 Naema                         
 309 Fraternitas           858 El Djezair     
 375 Ninina                859 Bouzareah   
 366 Vincentina            877 Valkure    
 373 Melusina              880 Herba   
 393 Lampetia              903 Nealley   
 395 Delia                 907 Rhoda   
 397 Vienna                921 Jovita                      
 407 Arachne               931 Whittemora   
                           938 Chlosinde   
 429 Lotis                 992 Swasey   
 491 Carina                999 Zachia        
 527 Euryanthe            1062 Ljuba          
 541 Deborah              1269 Rollandia   

In case of any questions, please contact Dr. Anna Marciniak at:


[1] Marciniak et al. 2015, "Against the bias in spins and shapes of asteroids", Planet Space Sci. 118, 256; arXiv:1711.02429
[2] Marciniak et al. 2018, ''Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids'', Astronomy Astrophys., 610, A7; arXiv:1711.01893
[3] Marciniak et al. 2019, ''Thermal properties of slowly rotating asteroids. Results from targeted survey'' Astronomy Astrophys., 625, A139, arXiv:1905.06056
[4] Pál et al. 2020 ''Solar System objects observed with TESS -- First data release: bright main-belt and Trojan asteroids from the Southern Survey'' ApJS 247, 26; arXiv:2001.05922