Comet C/2013 US10 Catalina shows off a compact green coma and two tails in this photo taken this morning  (Nov. 20, 2015) at dawn from Arizona. Credit: Chris Schur

Comet Catalina Grows Two Tails, Soars at Dawn

22 Nov , 2015 by

Amateur astronomer Chris Schur of Arizona had only five minutes to observe and photograph Comet Catalina this morning before twilight got the better of the night. In that brief time, he secured two beautiful images and made a quick observation through his 80mm refractor. He writes:

“Very difficult observation on this one. (I observed) it visually with the 35mm Panoptic ocular. It was a round, slightly condensed object with no sign of the twin tails that show up in the images. After five minutes, we lost it visually as it was 2° degrees up in bright twilight. Images show it for a longer time and a beautiful emerald green head with two tails forming a Y shaped fan.” 

Comet Catalina was about 3 high over Lake Superior near Duluth, Minn. IU.S.) at 5:55 a.m. this morning. Stars are labeled with their magnitudes. Details: 200mm lens, f/2.8, ISO 1250, 3-seconds.

Comet Catalina stands some 3° high over Lake Superior near Duluth, Minn. (U.S.) at 5:55 a.m. this morning, Nov. 22. Stars are labeled with their magnitudes. Details: 200mm lens, f/2.8, ISO 1250, 3-seconds. Credit: Bob King

Schur estimated the comet’s brightness at around magnitude +6. What appears to be the dust tail extends to the lower right (southeast) with a narrower ion tail pointing north. With its twin tails, I’m reminded of a soaring eagle or perhaps a turkey vulture rocking back and forth on its wings. While they scavenge for food, Catalina soaks up sunlight.

I also headed out before dawn for a look. After a failed attempt to spot the new visitor on Saturday, I headed down to the Lake Superior shoreline at 5:30 a.m. today and waited until the comet rose above the murk. Using 7×50 binoculars in a similar narrow observing window, I could barely detect it as a small, fuzzy spot 2.5° south of 4th magnitude Lambda Virginis at 5:50 a.m. 10 minutes after the start of astronomical twilight. The camera did better!

Chris's first photo was taken when the comet rose. This one was photographed minutes later with twilight coming on. Credit: Chris Schur

Chris’s first photo was taken when the comet rose. This one was photographed minutes later with twilight coming on. Credit: Chris Schur

With the comet climbing about 1° per day, seeing conditions and viewing time will continue to improve. The key to seeing it is finding a location with an unobstructed view to the southeast — that’s why I chose the lake — and getting out while it’s still dark to allow time to identify the star field and be ready when the comet rises to greet your gaze.

Two views of Comet C/2013 US10 Catalina made around 6:23 a.m. EST (11:23 Universal Time) on Nov. 21st. The left photo is a 30-second exposure with dawn light approaching fast. Exposure at right was 10 seconds.

North is up and east to the left in these two photos of the comet made by Dr. D.T. Durig at 6:23 a.m. EST on Nov. 21st from Cordell-Lorenz Observatory in Sewanee, Tenn. He estimated the coma diameter at ~2 arc minutes with a tail at least 10 arc minutes long . “I get a nuclear magnitude of 10.3 and an total mag of around 7.8, but that is with only 5-10 reference stars,” wrote Durig. Credit: Dr. Douglas T. Durig

Alan Hale, discoverer of Comet Hale-Bopp, also tracked down Catalina this morning with an 8-inch (20-cm) reflector at 47x. He reported its magnitude at ~+6.1 with a 2-arc-minute, well-condensed coma and a faint wisp of tail to the southeast. In an e-mail this morning, Hale commented on the apparent odd angle of the dust tail:

“Since the comet is on the far side of the sun as seen from Earth, with the typical dust tail lagging behind, that would seem to create the somewhat strange direction. It  (the tail) almost seems to be directed toward the Sun, but it’s a perspective effect.”

Venus glares inside the cone of the zodiacal light this morning at the start of astronomical twilight over the shoreline of northern Wisconsin. Jupiter is seen at top and Mars two-thirds of the way from Jupiter to Venus. Credit: Bob King

Venus glares inside the cone of the zodiacal light this morning at the start of astronomical twilight. Jupiter is seen at top and Mars two-thirds of the way from Jupiter to Venus. Arcturus shines at far left. Credit: Bob King

There were side benefits to getting up early today. Three bright planets lit up Leo’s tail and Virgo’s “Cup” and a magnificent display of zodiacal light rose from the lake to encompass not only the comet but all the planets as well.

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Brian Sheen
Member
Brian Sheen
November 22, 2015 2:19 PM

Hi

I assume that the Fan shape formed of the two tails is as a result of it being just past perihelion. One tail always marks out the track taken by the comet the other points directly away from the Sun. Add in the its rather transitory location there there we have it. I know it is more or less as Alan has it.

Aqua4U
Member
November 22, 2015 3:30 PM

Yummy! Can’t wait~ Thanks for explaining our/N. Hemisphere observational perspective. Seeing the tail in that sun pointed orientation would definitely been one of those, “Say WHAT?” moments had I not known?

Aqua4U
Member
November 22, 2015 3:39 PM

It’s been almost a year of observations with my home build f3.6 12 1/2″ German Eq. Newt. and maan-o-man has she ever been good to me! (I LIKE galaxies!) Now it’s time for some payback, for me to be good to her? How’s about a new 3″ minor dia. secondary mirror for Christmas Baaaaby?

cschur
Member
November 22, 2015 5:52 PM

One other thought I get from this mornings images are that the comet is really quite small scale wise. Although once it is in a truly dark sky it may triple its size, a short focus newt may be the ticket here for a sharp close up that includes the entire comet and perhaps some field galaxies. What type of tail length were southern hemisphere imagers reporting before it dashed behind the sun?

Chris Schur

BlackWolfStanding
Member
BlackWolfStanding
November 22, 2015 6:21 PM

Due to obstructions, I can’t see it until it gets about 20 degrees above the horizon. sad

BCstargazer
Member
BCstargazer
November 22, 2015 7:33 PM

Thanks Bob.
As Catalina climbs up from the dawn’s horizon, it will become a popular topic even if it’s only marginally observable with naked eyes at around magnitude 4 or 5.
It won’t be long before we see the fantastically ridiculous claims on social media about its alleged influence on world events, “magical” properties or what’s hiding “behind” it.
When it departs the inner Solar System, never to come back again, I’ll be glad to have waived hello to this passing sublimating remnant of the stellar nursery that gave birth to our Sun on those upcoming chilly December mornings smile

Aqua4U
Member
November 22, 2015 8:43 PM

What is your favorite comet sighting? Would that be Comet Halley? Shoemaker/Levy 9? Hayakutake? Hale-Bopp? Holmes? Lovejoy? 73P/Schwassmann–Wachmann? Whoa.. thinking back on those observations makes me think that maybe asking for a top ten list would be more reasonable? But were I to pick one… it would have to be…. Hale-Bopp… maybe.

Gozlemci
Member
November 22, 2015 11:47 PM

Thanks Bob…
After nice Hale-Bopp observations (long time ago), I hope, Catalina may be a good candidate for unaided observation…

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