Comets ISON and Lovejoy

October 18, 2013


CometLovejoyNucleusChumackHR2web (3)

Photographer: John Chumack
Summary Author: John Chumack

Shown above at top is Comet ISON as observed on October 9, 2013 and at bottom is Comet Lovejoy as observed in late September 2013. ISON was captured at John Bryan State Park, and Lovejoy was snapped from my backyard observatories in Yellow Springs, Ohio. Comet ISON (C/2012 S1), a sun-grazing comet, is now sporting a decent tail (observed only telescopically) and predictions indicate that it’ll brighten considerably by mid November. On this image, I estimate that its magnitude is approximately 12.5. ISON is currently in the vicinity of Mars orbit. As it approaches the Sun it may get as bright as Venus (-4 magnitude). But you never know comets; ISON could be fantastic or it could break apart and fizzle out. I've been imaging Comet ISON since its discovery last year and was asked by the University of Maryland and NASA to participate in NASA’s Comet ISON Observing Campaign. So I'll be imaging this comet every clear night through its perihelion passage, on November 28, and throughout December and January as well.

Comet Lovejoy (C/2013 R1) is a newly discovered long-period comet. Its discovery was announced on September 9, 2013 – first observed by Australian amateur astronomer Terry Lovejoy. I observed Comet Lovejoy on the same night I spotted ISON. It was moving through the Constellation of Monoceros (The Unicorn) – found to the left or east of Orion. The blue-green outer envelope or outer coma of Lovejoy is attributable to carbon molecules (C2). Comet Lovejoy is at about 12th magnitude on this image but is predicted to brighten to 8th magnitude later in the fall – a small telescope will be needed to see it. So make room Comet ISON, you’ll have to share the morning sky in November and December with Comet Lovejoy.

Photo details of Comet ISON: Made with a QHY8 cooled color CCD camera and my home-made 16 in (40 cm) diameter, F4.5 Newtonian telescope; a single 5 minute exposure  at 10:09 UT; 7.8 x 7.8 micron pixels; 1510 x 1010 effective array; working in monochrome mode binned 2x2; 1.76 Arc/per pixel. 

Photo details of Comet Lovejoy: Made with a QHY8 cooled color CCD camera with my homemade 16 in (40 cm) diameter telescope; 25 minute exposure tracking on the comet’s nucleus; captured on September 22, 2013.