An inner main-belt asteroid , P/2010 A2 , was discovered on January 6th , 2010 .
Based on its orbital elements , it is considered that the asteroid belongs to the Flora collisional family , where S-type asteroids are common , whilst showing a comet-like dust tail .
Although analysis of images taken by the Hubble Space Telescope and Rosetta spacecraft suggested that the dust tail resulted from a recent head-on collision between asteroids ( 21 ; 32 ) , an alternative idea of ice sublimation was suggested based on the morphological fitting of ground-based images ( 27 ) .
Here , we report a multiband observation of P/2010 A2 made on January 2010 with a 105 cm telescope at the Ishigakijima Astronomical Observatory .
Three broadband filters , g ^ { \prime } , R _ { c } , and I _ { c } , were employed for the observation .
The unique multiband data reveals that the reflectance spectrum of the P/2010 A2 dust tail resembles that of an Sq-type asteroid or that of ordinary chondrites rather than that of an S-type asteroid .
Due to the large error of the measurement , the reflectance spectrum also resembles the spectra of C-type asteroids , even though C-type asteroids are uncommon in the Flora family .
The reflectances relative to the g ^ { \prime } -band ( 470 nm ) are 1.096 \pm 0.046 at the R _ { c } -band ( 650 nm ) and 1.131 \pm 0.061 at the I _ { c } -band ( 800 nm ) .
We hypothesize that the parent body of P/2010 A2 was originally S-type but was then shattered upon collision into scaterring fresh chondritic particles from the interior , thus forming the dust tail .