Comet ISON Update Dec. 7 – Possible Sightings, New Map

Comet ISON in the most recent good resolution image taken by NASA’s STEREO-A probe late on Dec. 3. I’ve processed the photo to better show the comet, which has now become a faint, expanding cloud of dust and small rocks. Credit: NASA

Yesterday morning I dressed for subzero chill to look at comets Lovejoy and Nevski, Mars and a faint supernova in the constellation Leo. Although my hour under the stars didn’t lack in astronomical pleasures, I couldn’t help thinking about ISON. This week was supposed to be the start of that comet’s grand entry into the dawn sky after getting fired up by the sun. Instead we’re hoping to catch a glimpse of its final gasp. When I packed away the telescope and returned to the welcome warmth of my home, I felt a tinge of comet blues.

While you might share my disappointment, the good news is that ISON seems to have just enough oomph to re-appear in the sky before dawn. To date, there have been two possible and one positive sightings:

* Piotry Guzik of Poland strongly suspected seeing a faint 1/4-degree-wide smudge with 10×50 and 15×70 binoculars Friday morning Dec. 6 at dawn.

* A possible picture of the comet was taken by David Rankin also on Dec. 6. Rankin’s image is particularly interesting because it shows maybe-ISON in the correct orientation “lying on its side”. (I just heard this morning that the comet’s position in the photo is off by one degree from its predicted position, making it doubtful we’re seeing the comet. Perhaps it’s a cloud?).

* This morning Dec. 7, J. J. Gonzalez of Spain made what appears to be a definitive observation of the comet with an 8-inch (20 cm) telescope at magnitude 7.2 from his dark, mountaintop location. He described it as 10 arc minutes across (30 arc minutes = one full moon diameter), elliptical in shape and nearly smooth with very little brightening toward its center. Gonzalez also spied two faint, tail-like structures extending to the south and northwest.

I suspect the digital imagers will be out in force over the weekend. We’ll know very soon what ISON’s ghost looks like from the ground.

Michael Jaeger of Austria photographed this tail disconnection event in Comet Lovejoy on Dec. 5, 2013. Comets can lose their tails when magnetic fields entwined with the solar wind snap it off. Like some lizards, a new one quickly re-grows to replace the old. Credit: Michael Jaeger

Comet Lovejoy compensated for whatever twang of regret I felt at not seeing ISON leap over the trees. How fortunate we are to have this picturesque and interesting stand-in for the much-hyped ISON. In my dark eastern sky, Lovejoy could still be seen with the naked eye as a small, “soft” star of magnitude 5.5 in the constellation Corona Borealis. Fainter than a week ago, it will soon fade below the naked eye limit.

Fountains or jets of material launching from the Lovejoy’s nucleus are visible in moderate-sized telescope (8-inches and up) at powers of 200x and higher. This photo taken Dec. 5, 2013. Credit: Gianluca Masi

In 10×50 binoculars a streak of a tail shot up northwest of the bright head. I could trace it for 2.5 degrees. Fascinating fountain-like structures similar to the what you see in Gianluca Masi’s photo sprung up south-southeast of Lovejoy’s core when viewed at high magnification.

After 20 minutes of study I balled my hands into fists inside my gloves to warm them back up and then moved on to Mars.

Lovejoy slowly drops lower and lower in the morning sky over the next few weeks. You’ve got another 7-9 days of good viewing before the full moon returns to the morning sky. Use this chart to help you find it. That’s also the same amount of time left to attempt to see Comet ISON. Because it’s so amorphous and dim, moonlight will almost certainly kill it visually, though amateurs may still be able to get images.

New map for finding Comet ISON shows the sky facing east an1 1/2 to 1 3/4 hours before sunrise for mid-northern latitude skywatchers. The comet’s position is shown daily but marked every 3 days. Stars plotted to mag. 6. Guide stars are labeled: Oph = Ophiuchus, Her = Hercules, Ser = Serpens and CrB = Corona Borealis. Click for a large version. Created with Chris Marriott’s SkyMap software

My original ISON charts assumed the comet would be relatively bright in a twilight sky. This freshly baked map reflects the new reality and shows a lot more stars to hopefully help guide you to your target.

Keep in mind that the map shows the constellation positions for Dec. 7. Each night the stars rise 4 minutes earlier  and push up one degree higher in the east. Add that to the comet’s rapid northward motion, and ISON gains altitude quickly in the next week, making a little easier to see each morning … assuming you can see it! On the 7th, for example, the comet is about 6 degrees high at map time; by the 14th, it climbs to 22 degrees.

20 Responses

  1. Edward M. Boll

    Freshly baked map for a completely baked comet. I would enjoy Lovejoy if we we were not colder than North Pole, Alaska this morning

  2. christine byng

    I just witnessed comet ISON a few minutes ago. Originally I thought what a strange looking Jetstream! That was when it suddenly shifted angles going almost vertical and then switched to the opposite angle from when \I first spotted it. I saw it large \7 clear with my naked eye. I wasn’t following this comet’s travels \I just happened to go outside to have a smoke with my coffee. AWESOME! Thanks for your guidance; from now on I will be prepared and have my camera ready. Again thank you.

    1. astrobob

      Hi Christine,
      I hate to disappoint you but you must have seen something else because the comet is very faint. You would need very dark skies and at least a pair of binoculars to see Comet ISON. Also, the comet would not have changed appearance so quickly. It would look static. Perhaps you saw a jet contrail?

  3. Edward O'Reilly

    Yes,comet watching for next while will be tinged with some regret and an ‘if only’ feeling;just no way around that.Interestingly enough,have you noticed how Lovejoy and Ison will be passing each other in the night,around Dec 17 or so? Ison moving up with time,Lovejoy moving down.If Ison had only cooperated,we would have had 2 prominent comets only several degrees away from each other in mid December skies. If only,indeed!…..

    1. astrobob

      How true! At least with the recent positive sighting we can hope to see what’s left of our wishful thinking 🙂

  4. Comet ISON blues? ME TOO! I was so looking forward to a spectacular December Comet ISON. Now, I’ll just wait and hope the January ISON meteor shower will bring some fun surprises!

    1. astrobob

      I hope that shower amounts to something. I’ve heard conflicting reports that it will and won’t be visible with the naked eye.

  5. Giorgio Rizzarelli

    Hi Bob, ISON negative report here, limiting its magnitude at 16.5 or dimmer, by a professional (IAU member) at an observatory with a 40cm scope, SBIG camera and even tracking at the velocity of the hypothetical comet.
    and at:

    This quite contrast with the Gonzalez’s observation you kindly reported, at mag7 with 20cm scope, also because of the mag 14 limit of a 20cm scope.

    I’ll keep checking if someone posts images on Spaceweather and will wait for more negative reports to confirm, but I fear it’s the end of the adventurous ISON story. Sorry to give bad news but it spares us a useless dawn session. Of course looking forward to your opinion.

    1. astrobob

      It does not look good. However the field of view of both scope was relatively small – I’ll be absolutely convinced when someone like Michael Jaeger or Damian Peach gets a negative in their wider views.

      1. Giorgio Rizzarelli

        Yes, his scope/camera setup has about 1° FOV, and the comet dust may be very scattered. His report for sure excludes a decent fragment. He also said he couldn’t do the BG flat because of trees. I’d add, twilight may also have been the problem – he photographed the target when it was at alt 10° and that time was around twilight beginning also there in Canada, according Stellarium. The comet dust may still be too close to the Sun to draw conclusions. Let’s see.

        1. astrobob

          Yes, I think you really need a wide (and deep) field image to confirm for sure. We’ll soon see. Must be cloudy at Michael’s house still in Austria.


    Hello Bob,
    After a week of overcast & snow in NE finally a clear sky to see Lovejoy. It is very easy to find a fuzzy coma & tail in Binoculars. Its perihelion is @ 12/21 but why is its magnitude is fading & not getting brighter ? > NEMIKE

    1. astrobob

      Excellent question. It’s because the comet has been getting farther from Earth since November. Lovejoy was closest to us on Nov. 19 at 37 million miles; it’s now 65 million miles away. It may be getting intrinsically brighter as it approaches perihelion, but that extra distance causes it to fade from our perspective.

      1. NEMIKE

        Thanks Bob for your reply. This website is always dependable for accurate information. Lovejoy has been easy to find with my binoculars but the cloudy skies have been my nemesis. Hope to get see more of it before its gone. It has been a slightly brighter comet than expected. Waiting for the next Hale-Bopp. Too bad you can’t do anything about the weather. > NEMike

        1. astrobob

          Thanks Mike. It won’t be too long before the moon thins enough for a great view again. I’ll be setting the alarm later this month to check on Lovejoy and C/2012 X1.

Comments are closed.