Oct. 26, 2015

P. Jenniskens, SETI Institute and NASA Ames Research Center; and J. Vaubaillon, Institut de Mecanique Celeste et de Calcul des Ephemerides, Paris, report that the close approach to the earth (0.0033 AU) of 2015 TB_145 (cf. MPEC 2015-T86), a possible dormant comet, is not expected to produce associated meteors in 2015. From a model that evolves meteoroids ejected by outgassing from this object since 1850, they calculated that meteoroids will pass > 0.0007 AU outside of the earth's orbit on 2015 Oct. 31d17h05m UT (between 15h and 19h UT). If, due to different ejection conditions or physical properties than assumed in the model, associated meteoroids do cross the earth's path, then meteors would radiate from geocentric position R.A. = 64.3 deg, Decl. = -3.0 deg (equinox J2000.0), with geocentric speed 34.8 km/s, and would be best seen in Asia. The model calculates a strong potential past shower outburst in 2009 between solar longitudes 217.85 and 217.99 deg (equinox J2000.0), with peak at 217.91 deg, while weaker shower outbursts may have occurred in 2013 and 2014. The SonotaCo meteoroid orbit survey (Kanamori 2009, JIMO 37, 55; see website URLhttp://sonotaco.jp/) did not cover the relevant time period in 2009, but the "Cameras for Allsky Meteor Surveillance" program (CAMS; cf. Jenniskens 2011, Icarus 216, 40; see URLhttp://cams.seti.org) did cover the period of expected activity in 2013 and 2014. No activity was observed in the presumed area of the sky. The model predicts that the encounter in 2016 would be between solar longitude 217.75 and 218.04 deg (peak at 217.90 deg).

Also, the CAMS and SonotaCo video meteoroid orbit surveys (which generally detect meteors in the magnitude range +4 to -2) did not detect a meteor shower associated with 2015 TB_145 in the week centered on the expected peak activity during 2007-2014.