Comet ISON Observing Guide For Post-perihelion Optimists

No one knows yet if Comet ISON will survive to become visible in the dawn sky in December. Assuming the best case, here’s a map to help you find the comet as it treks through Ophiuchus, Serpens and into Hercules from Dec. 3-15. The map shows the sky 45 minutes before sunrise for mid-northern latitudes (42 degrees N. specifically) facing east-southeast. The planet positions are shown for Dec. 3. Mercury will soon depart the morning sky. Key stars near the comet’s path are labeled. Click to enlarge. Stellarium

Granted it’s a long shot, but there’s a chance we could still see Comet ISON in the morning sky very soon. Many of you tried to find the comet before perihelion and got skunked either by bad weather, bright twilight and ISON’s overall weak performance.

Comet ISON this morning at 9:14 a.m. CST photographed by the ever-diligent SOHO coronagraph. Credit: NASA/ESA

Today it appears somewhat brighter than Antares in Scorpius, maybe about magnitude 0.  While still too close to the sun to see at that brightness and likely to fade further in the coming days, the next opportunity to see it with our own eyes will be around Dec. 3. That’s when ISON might be high enough in the dawn sky to punch through the horizon haze and twilight glow. On the bright side, there will be no moon to glare up the sky.

The most idealistic among you might try for the comet as soon as Sunday morning Dec. 1. This map shows the sky 45 minutes before sunrise seen from mid-northern latitudes (42 degrees north specifically) facing east-southeast. Even if you miss ISON, the lineup of Mercury, Saturn and a super thin crescent moon should be ample reward for your trouble. Stellarium

With that in mind and forever optimistic – one of the “curses” of being an amateur astronomers – I’ve prepared a couple chart to help you find ISON … one more time. My fellow amateurs and I here in Duluth, Minn. will be out. Nothing like the chill of a December dawn to awaken the senses. I hope you’ll try too.

To attempt an ISON observation, find a place with a wide open horizon to the east-southeast and use binoculars. As the days tick by, the comet will quickly rise higher in the sky, the exact opposite of its performance in mid-November. By about Dec. 7, you can look for the comet in a dark sky 1 1/2 hours before sunrise. Good luck on Round 2!

Nice composite image of Comet ISON making its hairpin turn around the sun yesterday Nov. 28. Credit: ESA/NASA/SOHO/SDO/GSFC

16 Responses

  1. Mahdi

    Yes, but when you are asleep, we are awake and no update, and when you wake up and post something, we are asleep. And it’s a vicious cycle.
    But it doesn’t matter. Thanks again for every post from panstarrs to ison.

    1. astrobob

      Mahdi,
      I see what you mean. If you regularly observe the sky we could use that to our advantage. During a major astronomical event you could share your observations with readers here in the Western Hemisphere. We then share ours with you. Of course the Internet makes sharing at any time possible, which is how we got to meet each other in the first place. Thanks again for writing Mahdi.

  2. Gonzalo

    Hello Bob and many many thanks for your fresh reports about ISON progress!!!
    I am really hapy knowing that this unpredesc. comet is alive!!!

    Please I would like if ISON will be visible from Cochabamba Bolivia
    Long 66 deg 08 m Lat minus 17 deg 25 minutes

    I saw that the first days on December comet will rise almost with Sun but after December 10 will be more or less more difficult for observation Isnt´??

    Clear Skies !!! For all of You!!

    1. astrobob

      Hi Gonzalo,
      We will all have to wait to find out if anyone will be able to see the comet in the next few days. It looks like it’s fading again. Unfortunately, Bolivia is too far south for a good view except for the first few days of December. I once traveled to Arequipa, Peru near the El Misti volcano – as close as I have been to Bolivia. The people, the native music and the beer were all wonderful.

  3. Edward O'Reilly

    Yes,many thanks for your insights,Bob and,of course,for your valuable maps;I’m in a moderate sized city(but where I am isn’t excessively light polluted) but have an excellent view of eastern horizon;will probly try for Ison on Dec 1(with binos and weather permitting);will be interesting to see what kind of display Ison offers,no longer expecting anything spectacular but perhaps low-end naked eye visibility isn’t out of the question.

  4. Rick Morgan

    Hi Bob, From 6:05-6:35 am this morning I attempted to see Comet ISON from High Point, NC (Lat 36 N, Long 80 W.) Skies were clear until wispy cirrus clouds blocked the horizon. I had no success seeing the comet thru 8×40 binocs, but it was a treat to see the 28-day old Moon (3%), Saturn, and Mercury form a neat little asterism. Also saw Mars (Leo) and Jupiter before sunrise.

    1. astrobob

      Thanks for trying Rick. You are an optimistic soul! Like you, even if I don’t find my intended object, there’s plenty else to see and enjoy.

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