Saturday, October 5, 2013

ISON UPDATE, Latest Images. Red Aurora/Both Poles.

ISON's Path and Sunday Night's CME Update. 

The total brightness of the comet within a 0".24-diameter aperture remained unchanged within 0.03 mag over the 19-hr observing window. Broadband photometry yielded Af(rho) = 1376 cm at 589 nm, and 1281 cm at 433 nm, consistent with a red slope of 5 percent per 0.1 micron for the coma dust.

A well-defined jet is visible after removing the 1/r brightness distribution. The jet is centered on position angle 290 deg, with a cone angle of 45 deg, a projected length of 1".6, and a slight curvature towards the north near the end. No temporal change in the morphology is observed over the three epochs, suggesting that the jet is circumpolar.