Peach-Comet Catalina-2015-12-08
Comet Catalina (C/2013 US10) on December 8. Sadly, the comet's two tails show up well only in photographs. (Damian Peach)

Keeping Up With Comet Catalina

Now’s the time to enjoy the latest binocular comet.

Note: See updates following the story.

It’s been a while since we’ve had a comet bright enough to be viewed in binoculars, but the wait is over. Say hello to Comet Catalina (also known as C/2013 US10).

The comet was discovered on October 31, 2013, by researchers working on the Catalina Sky Survey, a project designed to find comets and asteroids that might come close enough to Earth to pose a collision hazard. When C/2013 US10 was picked up, it was still inbound on its way to the inner solar system. It reached perihelion (its closest approach to the Sun) on November 15, 2015. Since then has been slowly heading northward as it returns to the icy outer reaches of the solar system.

Peach-Comet Catalina-2015-12-08
Comet Catalina (C/2013 US10) on December 8. Sadly, the comet’s two tails show up well only in photographs. (Damian Peach)

Observing from his home in Chilliwack, British Columbia, SkyNews contributing editor Ken Hewitt-White spotted the comet on November 30 with his 4¼-inch reflector telescope. “In the finderscope I could see Kappa Virginis rising over my neighbour’s roof — the comet was supposed to be just below that star,” Ken reports. “I aimed the scope at Kappa, dropped down a bit, and — bingo — there it was! Not much to see: just a fuzz with no tail.”

The comet passed closest to our planet on January 17, but was more than 100 million kilometres away — no need to worry about a collision! Enjoy the show while you can. Comet Catalina has a one-way ticket out of the solar system. After this visit, it’ll be on its way to interstellar space, never to be seen again.

Comet Catalina Path
Comet Catalina’s position is plotted for 11:30 p.m. (EST)

December 6, 2015 update: The comet’s position in the morning sky is improving and its brightness appears to be holding steady at about magnitude 6.5. SkyNews associate editor Alan Dyer viewed the comet this morning from Quailway Cottage near Portal, Arizona. He writes, “The comet was just visible in small binoculars as a fuzzy spot. In my photo (below), its two tails, ion and dust tail, are just visible in the bright moonlit sky (the waning crescent Moon was well above Venus this morning). Still, the comet is not as bright or obvious in binoculars as I’d hoped!”

Dyer-Comet Catalina and Venus, December 6.
Comet Catalina and the planet Venus on the morning of December 6, 2015. (Alan Dyer)

December 16, 2015 update: We’re approaching one of the comet’s prime observing windows. Ken Hewitt-White was able to spot it from his backyard in Chilliwack, British Columbia, and writes: “It was fairly easy to see in my 7×50 binoculars, looking like a slightly fainter version of M13. Two stars stood one degree to the left (east-northeast) of the comet — the more northerly 6.2-magnitude star seemed perhaps a bit brighter than the comet, and the southerly 6.8-magnitude star was definitely fainter. I’d say the comet was about magnitude 6.3 or 6.4. In my 4.25-inch scope at 27× Catalina was small and spherical but bright and delicately diffuse. No tail was clearly visible in my sky conditions, though I kept thinking I could detect just a hint of one. At 72×, the comet was big, pleasingly bright, and noticeably condensed toward the middle — rather like the way a compact, unresolved globular cluster appears in a small scope at low power.”

December 30, 2015 update: Comet Catalina is continuing to hang in at about magnitude 6.3. Ken Hewitt-White, viewed the comet with 7×50 binoculars at 4 a.m. on December 30 from his darkened dining-room window in Chilliwack, British Columbia. “The comet, a few degrees below Arcturus, was easy to locate. It appeared small, round, bright in the middle, but tail-less. However, it was bigger and easier to detect (despite the moonlight) than when I last saw it in mid-December,” Ken reports.