Comet C-2017 T2 PanSTARRS

Comet C-2017 T2 PanSTARRS, is passing through the constellation of Ursa Major (the Great Bear, a.k.a. Pappa Bear!!!) and just recently passed close by the galaxies M81 and M82. It's now heading directly towards the smudge you see below it towards the bottom of the page. That's IC2574, or Coddington's Nebula, a dwarf spiral galaxy (class SABm) which is an outlier of the M81 Group of galaxies, at adistance of 12.8Mly (3.93Mpc). The galaxy subtends 12.02 arcminutes along its main axis, giving it a true diameter of 44754.9ly. Studies have shown that the galaxy appears to consists mostly of dark matter, at around 90% of its mass The Hubble Class of SABm denotes that this galaxy is barred, with very loosely wound and messy looking spiral arms, with little to no hint of a nuclear bulge or core. The galaxy was discovered in 1898 by American astronomer, Edwin Foster Coddington.

In a line slightly above IC2574 and towards the right hand side of the pic, about 1-3 of the way up, is the open cluster NGC3231, a rather loose collection of stars that subtends 4 arcminutes in diameter. Given that not much else is known about it, its actual size is unknown.

Back to the comet, the tail, with the faint extensions, appears to cross about 1-3 of the screen, making it nearly 1 degree in length or twice the size of the Full Moon, given the FoV (in piccie height) of 2.7 degrees. The green colouration of the coma of the comet is due to the ionisation of CN (cyanide) and C2 (diatomic Carbon) in the gases surrounding the nucleus of the comet.

Pic was taken with t20 (iTelescope, NMSO), LRGB composite (L=3x3 minutes, RGB=1x2 minutes each channel)
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