Category Archives: comet

comet

The Comet Wakes Up

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C2012 S1 ISON is Putting on a Show

Comet ISON captured by the TRAPPIST national telescope at La Silla, Chile. Courtesy ESO
Comet ISON captured by the TRAPPIST national telescope at La Silla, Chile. Courtesy ESO

Judging by this great image of Comet ISON just released from the European Southern Observatory, it’s safe to say that ISON is becoming the Comet of the Year for 2013. I know that naysayers have been muttering about what a fizzle it was, and it was kind of quiet. But, in the last couple of weeks, ISON has awakened and is putting doubts to rest.  This image shows activity in the plasma tail, which forms when gas molecules are ionized by the solar wind as the comet passes through.

I look at this image and see that perhaps the comet is about to experience what’s called a plasma tail disconnection event. That’s a “break off” of the plasma tail as it encounters a change of polarity in the solar wind. A new plasma tail will start to form immediately, and the old one will float off to interplanetary space.

Now, you’re probably wondering about seeing Comet ISON for yourself. You only have a few days left to really get a good look. To do it, you have to get up before dawn, and look to the east (which makes sense —the comet is on a headlong rush toward the Sun) after 5 a.m. Look for the Big Dipper. Once you find that, locate the curved handle, and follow that curve until you find the star Arcturus.  (You arc to Arcturus—one of  my favorite stargazing commands).  After that, curve down to Spica, and the comet shouldn’t be too far away from that star.   After that, it will appear to head toward Scorpius before angling back up toward Bootes and Corona Borealis in December. For good viewing charts, check out Astronomy.com and SkyandTelescope.com. Also, keep checking places like Spaceweather.com and Astronomy Picture of the Day for comet images as they come in.

The comet will slip out of view for a few days around November 28th, its closest approach to the Sun. There’s a school of thought among astronomers that it could break up due to the intense gravitational pull of the Sun (and the heat). If it does that, it’s anybody’s guess about how it will look after that. If it doesn’t break up, then look for the comet (again in the early morning) after about the 3rd or 4th of December. I also read that the Solar Dynamics Observatory (focused on the Sun) will be able to follow the comet through perihelion, so keep an eye on their Web page for a video release after perihelion. There’s still a lot of comet-gazing coming up, so check it out! (And, while you’re at it, get ready for Comet Lovejoy!)  Enjoy watching these incredibly cool bits of solar system history!

comet, comet dust, panSTARRS

A Comet Over Time

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Pan-STARRS Pans Out

 

Comet Pan-STARRS has been tantalizing viewers for weeks now, and we finally got our chance to see it this week. Of course, it clouded up and snowed for the first night, but for the past couple of nights we’ve been able to step out and watch it in the twilight about 40 minutes or so after sunset.  It’s not huge, it’s certainly not Hale-Bopp or Hyakutake, but it’s there and even folks who have never taken a pic of a celestial object before are getting some decent snaps of it. We set up our camera and tripod and took these timelapses of it last night, which was really the first time I could make it out naked-eye.

Comets are pretty cool — in both literal and figurative senses. They are made up of ice (mostly), and as they get close to the Sun they develop a dust tail, as well as (often enough) a plasma tail. The plasma tail is simply a long “tube” of gases that are energized by interactions with the solar wind. That interaction causes the gases to glow and that forms that second tail we often see in comet images. So, they LOOK cool, too!

If you get a chance to step outside over the next week, look west about 40 minutes after sunset and see if you can spot Pan-STARRS.  There are some gorgeous finder charts at Fred Espenak’s Astropixels site: they’ll help you locate the comet. And, don’t forget to bring along binoculars!