webspotting 31 - comets galore

As published in the Jun/Jul 2013 issue of SCOPE, the newsletter of the RASC Toronto Centre. Republished here with permission.

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There's been a lot of talk about comets this season. Many of you were fortunate to see (and photograph) comet C/2012 L4 Pan-STARRS [ed: correction, C/2011...] in the late winter. If you missed that deep solar system visitor earlier this year, the good news is that you can have another go at it! It remains in northern skies. In fact, as it moves from Cepheus, through Draco, and into Ursa Minor, you can catch it late-night or early in the morning, before dawn. Similarly, comet C/2012 F6 Lemmon is available to us, near Andromeda.

Both are around magnitude 6 or 7 at the time of writing, so well within the grasp of your binoculars or small telescope. The "big one" though, the comet that everyone seems to be talking about, is ISON. Due in the fall, some are predicting it to be extremely bright.

We'll see...

Did you know that at any given moment there are a dozen or more comets "around" in our night skies? By around,I mean that can be viewed or imaged in medium to large telescopes. Try with your big Dob at the cottage. Or use the Celestron 14" at the CAO.

I regularly use two web sites to monitor comets. I learned of one through Eric Briggs's The Sky This Month presentations. Seiichi Yoshida's http://aerith.net includes listings of visual and photographic comets. In the "Weekly Information about Bright Comets" page, the author gives a quick synopsis of each harbinger with a link.

The associated detailed page includes orbital data (which you could load into your favourite software, if it doesn't do it automatically), finder charts, brightness chart, and an amateur photograph.

The second resource I use is produced by the same person who developed the amazing SkyTools planning software. I confess: my SkyTools 3 Pro is usually not far away and I tend to check comet info there, make my own charts, and simulate views in eyepieces. But when my computer is not handy, I jump into http://cometchasing.skyhound.com to review our tantalising solar system bodies.

The Skyhound site shows a listing of comets with a visibility table or month calendar for each. The overall order of the list is important: the brightest comets are at the top; faintest at the bottom. Greg Crinklaw specifically notes equipment needed: Mark I Eye ball, binoculars, small, or large telescope. Again, he offers finder charts.

Hopefully you'll be able to add a couple more comets to your life list this summer. Happy hunting!