Comet C/2013 UQ_4 (Catalina)

An apparently asteroidal object discovered on Catalina Sky Survey images taken by J. A. Johnson last Oct. 23 with the 0.68-m Schmidt telescope (discovery images tabulated below) has been found to show cometary appearance recently by CCD observers elsewhere. The minor-planet designation 2013 UQ4 was assigned on MPEC 2013-U54 and MPS 483851. 2013 UT R.A. (2000) Decl. Mag. Observer Oct. 23.36760 4 23 47.37 -24 12 09.3 18.4 Johnson 23.37637 4 23 46.64 -24 12 17.4 18.7 " 23.38517 4 23 45.61 -24 12 25.8 18.6 " 23.39395 4 23 44.82 -24 12 34.9 18.4 " 23.48314 4 23 36.24 -24 13 54.9 18.1 " 23.48399 4 23 36.14 -24 13 56.0 18.4 " 23.48484 4 23 36.09 -24 13 56.9 18.4 " 23.48569 4 23 36.03 -24 13 57.1 17.9 " Michael Mattiazzo (Swan Hill, Vic., Australia) writes that the object appeared slightly diffuse with a coma diameter < 1' and of mag 13.5-14.0 on a 2-min exposure taken on 2014 Apr. 26.8 UT with a Canon 5D Mk II camera (+ 400-mm- f.l. f/2.8 lens) at low altitude. H. Sato (Tokyo, Japan) writes that six stacked 30-s R-band images taken with an iTelescope 0.43-m f/6.8 astrograph at Siding Spring on May 7.82-7.83 show a moderately condensed coma 25" in diameter with magnitude 14.5 as measured within a circular aperture of radius 12".8; follow-up observations with an iTelescope 0.51-m f/6.8 astrograph (+ luminance filter) at Siding Spring on May 14.8 show a diffuse outer coma of size 1'.7 and w-band magnitude 13.9 as measured within a circular aperture of radius 52".6. Twenty-six stacked 20-s images taken by T. Linder and R. Holmes (and measured with the assistance of L. Buzzi, S. Foglia, and T. Vorobjov) using a 0.41-m f/11 Ritchey-Chretien telescope at Cerro Tololo on May 16.4 show a strong central condensation with a 7" coma and a fan-shaped tail at least 15" long in p.a. 330 deg.