Comet ISON Is Here! (Part One)

Comet ISON continues to brighten on the way to its close encounter with the sun on November 28. Last week the comet reached naked-eye brightness, though that statement is a bit misleading. I suppose that if you had very dark, clear skies you might be able to glimpse it with the naked eye, but you would need to know exactly where to look, and it would appear as a very faint star. Over the past couple of weeks I’ve attempted to find Comet ISON with binoculars on nearly every clear morning. This has been hampered by my location in suburban Cincinnati. I’m on the south side, which, if you have to be near a large city, is the preferable place for doing astronomy. But there are many lights to my east, including those of the Cincinnati airport. Aided by the comet’s position and star charts, I looked but failed on several mornings. Finally, on Thursday, November 14, I saw it. It was very easy to find, and it was bright enough that I should have seen it on my previous attempts several days earlier. I reckoned that the comet must have undergone an outburst. Later in the day someone directed me to a news item on the web reporting that indeed it had.

What did Comet ISON look like? It looked like a small, fuzzy ball. I was seeing the coma, but there was no hint of a tail. My next attempt to see Comet ISON was the morning of Monday, November 18, 2013. The comet didn’t look quite as bright as it did a few days prior, but it looked larger, hazier, and a bit elongated. I probably was seeing a much larger coma and a bit of the tail. The outburst had settled down. Comets frequently have outbursts, so this behavior isn’t surprising. Comet ISON is rapidly getting lower in the sky as it continues to brighten. To see it you’ll have to start looking in a sky compromised by oncoming dawn, so after November 20 it will be very difficult to see. The following week is its rendezvous with the sun.

What will happen after perihelion passage on Thanksgiving Day? Comet ISON will brighten tremendously, though just how much it will brighten is unknown. It almost certainly will be bright enough to see and enjoy with the naked eye, though binoculars will help. I suggest you use this helpful diagram to assist you in looking for Comet ISON.

Comet ISON will be brightest at the beginning of December. Each morning it will climb higher in the sky, making it easier to see and in a darker sky. Unfortunately, it will rapidly dim as it gets higher. I plan to look for it every clear morning, as it will change every day. Though Comet ISON is unlikely to be quite as bright as we had hoped, it probably will put on quite a show.