Comet PANSTARRS naked eye from Tucson

This evening I was successful in visually seeing Comet C/2011 L4 (PANSTARRS) for the first time. Though not an easy object to see I was consistently able to observe it with the naked eye after ~7:00 pm when the comet had already descended to an elevation of ~4-6 degrees above the horizon.

The comet was much easier to see in 10×50 and 30×125 binoculars. Though the comet appeared as nothing more than a faint star to the unaided eye, its yellow color and 0.3-0.4 degree long tail were very obvious in the binoculars.

Due to the bright sky and lack of bright stars near the comet it was difficult to estimate the brightness of the comet. Using a few stars that were much higher in the sky and atmospheric extinction tables produced by Dan Green at the International Comet Quarterly, I estimated the comet to be magnitude +1.5.

Now that I’ve seen the comet, I can recommend that anyone attempting to see the comet for themselves needs the following: 1) a very clear horizon free of any obstructions, 2) binoculars and 3) plan your observations in advance to pinpoint exactly where the comet will be in the sky. For #3 I noted the point on the horizon where the Sun set and then determined that the comet would be located near the same azimuth of the location of sunset. Then it was just a matter of time (over 30 minutes after sunset) till the sky darkened enough for the comet to appear.

Bob King has a nice collection of finder charts that will help in locating the comet over the next few weeks. Finding the comet will be a little easier on Tuesday evening because a very thin crescent Moon will be located only a few degrees to the right of the comet.


  1. Tried all of that here in Dallas last night. There were about a dozen of us with scopes and binocs, all looking but none of us were able to see the comet. We’re all experienced with comet hunting and such… yet we just could not see it. However, we were clearly able to see faint stars in the area where the comet was supposed to appear. I wonder if people really are seeing this thing, or if it’s just wishful thinking and they’re seeing contrails, airplanes, cirrus wisps, etc. instead, thinking/hoping it’s the comet.

    1. Was at White Rock lake last night(wednesday) at the high point of where mockingbird and buckner come together. We could not see it Monday from there, but last night we definitely saw it. You can not see it with the naked eye though. I was using Nikon 16×50 binocs, and it was still fairly faint, but bright enough where I found it quickly each time I looked.

  2. On 10/03 it was maybe a bit early for us in the northern hemisphere.

    On march 15th, our astronomy club organizes a public observation session in the neighboring town of Folgensbourg (Alsace, northeastern France)… if the weather is with us (our climate is closer to the one in the UK than the one in Arizona!) I’ll try to shoot a few pictures of it and if you want send them to you.

    As you can see on our blog, we chose the place for it’s free from obstruction western horizon.

    Happy PanStarrs observation !

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