Comet ISON Update Nov. 27 – In The Home Stretch

Comet ISON this morning heads for the head of the constellation Scorpius as seen in this photo taken by the Solar Heliospheric Observatory. The sun, hidden by a mask, is represented by the white circle. Notice that ISON has a second tail feature – most likely dust particles released during the recent disruption of its nucleus. Credit: NASA/ESA

(Be sure to scroll to bottom for the latest update)

Sure, Comet ISON may be busting apart as you read this, but it’s still keeping up appearances as it swiftly approaches the sun today. The latest photo taken by SOHO at 6:42 a.m. CST today Nov. 27 shows the comet at about 1st magnitude, roughly the same brightness as Antares, the brightest star in Scorpius. A very thin additional streak of a tail shows alongside the main dust tail. It’s surmised that this new feature formed from various sized dust particles released during the recent break-up of the nucleus. It’s still possible the entire core didn’t entirely bust to bits – maybe it was only a large chunk.

Latest STEREO-A photo of Comet ISON taken Nov. 26 at 8:39 p.m. Credit: NASA

Either way, the comet’s remains fairly intact only a day before perihelion, almost guaranteeing we’ll at least get to see a very nice tail in the days following.

Check back often. I’ll update with the latest news on ISON. And for those that care little for comets, I appreciate you hanging in there. Our regularly scheduled programming will soon return!

UPDATE 10 a.m. CST: This just in from astronomer Matthew Knight at Kitt Peak observatories near Tuscon, Arizona – the comet has increased in brightness by a factor of at least 4 since entering the SOHO pictures yesterday evening. Wahoo!

Comet ISON as seen around 10 a.m. CST this morning Nov. 27 in SOHO. Note the spike from the comet’s head. This is an artifact created by the comet’s intensifying brightness. Credit: NASA/ESA

UPDATE 1 p.m. CST: A newer photo (above) shows that ISON continues to blossom. The spike is an electronic artifact called ‘blooming’. It happens when a celestial object is bright enough to saturate the camera’s CCD chip. Extra electrons released when light strikes the chip spill over into adjacent rows to create spikes and lines around the object. Blooming is a good sign that the comet is rapidly getting brighter. Stay tuned.

Latest pic from SOHO taken at 4:42 p.m. CST. Blooming of the comet’s head is becoming more intense indicating further brightening. The comet is now in the negative magnitude range. Click photo to see an awesome movie of the comet. Credit: NASA

UPDATE 4:30 p.m. CST: Space scientist and amateur astronomer Rob Matson reports that the comet has brightened into the negative magnitudes. In astronomy, the larger the negative number assigned to a celestial object, the brighter. There are only four stars – Sirius, Canopus, Arcturus and Alpha Centauri – and the planets Mercury, Venus, Mars, Jupiter and Saturn, along with the sun and moon that are rated as “negative”.

Last image from SOHO online Weds. night taken at 6:54 p.m. CST. Credit: NASA

UPDATE midnight Nov. 27-28: ISON estimated at -2 magnitude, but despite several amateur astronomers’ attempts to see and photograph the comet using telescope, binoculars and camera, nothing has been seen. There’s a photo circulating online by a Czech observer today that might show the comet but it’s still unclear if it’s the real item.

79 Responses

  1. Edward M. Boll

    I may go out Friday morning to see if I can see anything of ISON just before sunrise. A more sure sight would be Lovejoy, that morning just 3 degrees above 3rd magnitude 27 Bootes.

  2. Edward O'Reilly

    Does that put Ison just into the minus magnitudes,Bob? It may clear in time for sunset tomorrow here;I may try for Ison around then.Safest way is blocking out the Sun,using a building,and then trying to spot the comet with the naked eye. Ison is pretty close to the Sun to chance using a scope,binos-at least in my amateur hands!

    1. astrobob

      Hi Edward,
      Hard to say. At least mag. 1. Since we don’t know what the mag. was 24 hours ago, a 4x brightening would mean a 1.5 mag. increase. Based on the photo, it looks to be about mag. 1, maybe a bit better. We’ve got cirrus clouds here now. If you spot it, please let me know and I’ll include your observation on the blog asap. Anyone else reading this, we welcome any and all observations. Thanks!

  3. Edward O'Reilly

    I’ll do that,Bob-and thanks for the update.Don’t think it’ll clear here till late but fingers crossed.

  4. KC

    Bob – I live at 60 degrees N. I downloaded Comet ISON into Stellarium and it suggested that I won’t be able to see much. Is that accurate? I can’t really see why my latitude would have any bearing but I’m not really a “science talking guy”.

    1. astrobob

      Have no worries. You’ll be able to see it once it moves away from the sun in both the evening and morning skies. I’ll have maps very soon.

    2. Giorgio Rizzarelli

      @KC: If Bob allows me to add a few rows, I confirm that Stellarium generally gives and simulates quite wrong comet magnitudes. It’s a great tool, but comet magnitudes are difficult to predict. Stellarium is however generally right, at least approximatively, about comet coordinates (and it gives precise coordinates for ISON, as I’ve used for it various times).

  5. Edward M. Boll

    Was that little comet looking object Encke in that picture taken last night? Also I checked ISON tracker. I know that they do not update their magnitudes but they may be fairly close on ISON. A couple hours ago, they showed -0.2 for ISON.

  6. Hi Bob,

    Howdy, After a year of waiting, ISON is finally in ” The Final Countdown ”. I am praying for its survival, and got a feeling it will make it through and give us a good show this early december …!!

    Take care and Cheers !!

    James Moh.

  7. Giorgio Rizzarelli

    Thanx for the updates Bob. We’re comet-dependent or, as you said, in December (while chasing it at evening, night and morning) we’ll be all zombies.

  8. Edward M. Boll

    I do not know why but the ISON tracker that showed perihelion as 12;25, now shows it as 12:48 PM. tomorrow.



  10. Mindless Drifter

    Let’s start with the premise that ISON will survive in one piece it’s trip around the sun. I have seen reports that ISON is comparing well with LOVEJOY’s brightness in it’s approach to the sun. I have only seen LOVEJOY in pictures and it looked quite amazing. How long was LOVEJOY easy naked eye visible and what were the magnitudes during that time frame? It seems they be comparable. I hear iSON is much larger?

    1. astrobob

      Hi MD,
      Lovejoy was actually much brighter when seen by SOHO just before perihelion, but of course that may change at any hour. ISON could burst brightly if there’s a sudden and massive release of dust. Lovejoy was visible at mag. -3 on Dec. 17 after perihelion, faded to 1.0 by the 20th; 2.0 by the 21st and 5th mag. around Dec. 26.

  11. Edward M. Boll

    I just saw the report on Sky and Tel., but you had already printed it. Well, that beats Kohouek which made it to 0.0. It looks like ISON is still going to get more than 6 times closer to the Sun. This is very exciting!

  12. Mindless Drifter

    Thanks for the clarification on LOVEJOY. Us Earthlings got to see Hale-Bopp for 18 months and Hyakutake for a couple weeks with our own eyes sans optical improvement equipment. Are we going to have a 1 week window like we did for LOVEJOY? Was that quick loss in brightness due to the fact that it broke apart as it came around the Sun? If ISON holds together, is it possible that it is still naked eye on the 26th when it has it’s closest approach to earth?

    1. astrobob

      Yes, Lovejoy’s breakup definitely played a part in its fading. As for whether ISON will still be naked eye at Christmas, now that’s a good question. We should be able to better forecast that after tomorrow.

  13. Mindless Drifter

    Latest pis of ISON by SOHO at 2230 show multiple spiking on the nucleus. It is brightening very rapidly! It must be in negative magnitude easily now?

    1. astrobob

      Yes, I’ve got that photo up plus an awesome movie of same with a CME blowing by with ISON in view. I encourage you and others to watch the movie.

  14. Edward M. Boll

    There is still ignorance concerning ISON. I guess that I should laugh about it. One internet article said something to the effect of how to watch the death of the comet, as if it is sure to happen.

    1. astrobob

      Hi Mike,
      The comet has a velocity relative to the sun, which it is orbiting, as well as a velocity relative to Earth. Its velocity constantly changes in relation to both, which is especially noticeable now since it’s moving so rapidly as it dives toward the sun.

  15. Edward M. Boll

    I just checked the ISON tracker. They have it at magnitude -0.8. It may actually be a little brighter than that. That was not as exciting as the fact that I saw that it is now starting to go north. We certainly need a north direction if we are going to see it at all.

  16. Norman Sanker

    Hey Bob,

    I’m delighted that ISON looks like it may survive to put on a show in early December but what’s driving me mad is the total rubbish weather prediction for the next ten days here in Tucson. I can only hope some of those “partly cloudy” mornings will give me a peek to the east. Fingers crossed.

    Norman Sanker

    1. astrobob

      We’re all biting our nails over the forecast. Late Nov. and much of December are iffy for my region. It can be overcast for days then clear and become very cold for one or two days. Partly cloudy’s good by me!

  17. Kevin


    First let me say I’ve read numerous things online by you, and I must say, you SIR are the BERRIES!!!! Bob, I’ll be spending Thanksgiving and a few days after in the Southern New Hampshire area. At what time and direction would you recommend me looking? I’m pretty sure all the bad weather has moved out of New England and the visibility should be good. Thanks for your time AstroBob 🙂

    1. astrobob

      Hi Kevin,
      Thank you! I also happen to love berries (raspberries are a favorite). I will shortly be putting up a finder map on the blog for locating the comet on Thanksgiving. If you attempt it, exercise great care to avoid looking at the sun. More later – working on it at this moment.

      1. Kevin


        I know your busy with the finder map, so real quick. I spent some time years ago in Nova Scotia, the Blueberries up there are AMAZING!!!!!!! And the sky gazing was as well.

          1. Kevin


            That’s great!! I appreciate all your hard work. I just went out to look, about 6:45 EST and didn’t see it. I went out with my 6 year old daughter, I remember going out in the back yard with my dad when I was about 9 to see Haley’s. I would like to see it one more time in my life, it’s possible I’ll be…. what 85, every 76 years is it? I’ll keep checking the web and try to get her experienced!!!!

  18. Edward O'Reilly

    Bob,on the day of perihelion,should it be possible to track the comet all day long(weather permitting and if it is bright enough)since it is going to follow the Sun’s path quite closely?

    1. astrobob

      It’s going to be very near the sun all day – within 2.5 degrees – making it very difficult though not impossible to track unless it gets at least as bright as Venus or brighter. I’m writing up a guide for finding it as we speak.

  19. Mindless Drifter


    Heard that ISON rotates every 10 hours? How much % if any of it’s surface will be hit by heat and radiation for the first time? If this does happen, would it perhaps add to the gas and dust tails?

    1. astrobob

      Tough question. Since it rotates, it’s possible that most of the surface will ultimately be heated by the sun as it careens around it tomorrow. This likely is already happening. Any fresh surface exposed to the sun can potentially contribute to a boost in the comet’s dust production, but even surfaces constantly exposed can be heated during a close approach, develop cracks and blast out new dust and gas. That also goes for ice heated below the surface that vaporizes, expands and breaks through the crust to form new jets.

  20. Mindless Drifter

    Hi Again AstroBob,
    I have a 8″ Celestron Dob. I do not have a solar filter. I do have a lunar filter. Is there anything i can do with the limited filter I have and perhaps jury rig something i.e. cover up most of the opening where the light comes in and use the lunar filter in combo? or? or should I just forget it and save my eyesight. Thanks!

    1. astrobob

      Your lunar filter will not protect you from direct sunlight. Best is to move the scope to a place where you can completely block the sun from view by a light fixture, rooftop or power pole and do your search that way. I’ll have other suggestions also in the article. Look for it in early a.m. tomorrow.

      1. Mindless Drifter

        Thanks for all your answers and information! I will check your article in the morning. As for ISON, I am hoping for a awesome comet!

          1. Giorgio Rizzarelli

            Pay attention if you have light clouds around Sun because they diffuse sunlight. And if you use a pole to shield Sun keep into account that Sun’s position in sky moves.
            PS Solar filter would not help because would not show the comet.

  21. Edward M. Boll

    Last official report, about an hour or so ago, put the comet around magnitude -2, possibly a 3 magnitude increase just today. We will see what happens tomorrow.

    1. astrobob

      A New Zealand amateur tried for it a short while ago in his 16-inch. He found Antares easily but no sign of the comet.

      1. astrobob

        Hi Jim,
        Yes, if true. This morning’s photo still shows a nice spike but I would have expected more. The head looks a tad smaller too.

  22. MAXFLI10

    Total newby to all of this, so please pardon my ignorance. G/f. & I want to get up early thanksgiving morning to see this. 1 Hr before sunrise? Are we supposed to see it then or is there a better time?

    1. astrobob

      You won’t see the comet before sunrise just now. Just wait a few days and it will return to morning twilight.

  23. Richard Keen

    Bob, I enlarged that photo from Slovakia to seek the comet, and found several dots that one might think are ISON. But the dots all look the same, so unless there’s four or more comets near the sun today, I’d suspect all the dots are something else.
    Is there a version pointing out what they think is the comet?

    1. astrobob

      I don’t think it’s a comet based on one simple fact: his shutter speed was 1/4000 second. Maybe I’m wrong but I don’t think it’s possible to record what would have been a first magnitude object at that speed. Others are also finding additional white dots in the photo.

  24. Edward O'Reilly

    As for the New Zealand report,perhaps the comet has past the point where southern hemisphere observers can see it?

    1. astrobob

      Edward R,
      They should have no problem attempting a daylight observation, but after that, southern hemisphere observers have only a few days before the comet’s too and finally disappears from view.

  25. Edward M. Boll

    I am up at 7, ready to check the sky. Let us see what the comet will perform today. I made the comment that about the time it starts to cool down from it’s 5000 degrees, our turkey will cool down from it’s 500 degrees. I would not be totally surprised to see nearly a magnitude increase every hour for the next 5 hours or so.

    1. astrobob

      Looks to me like the comet has not brightened much overnight after seeing the latest SOHO image this morning.

  26. Edward M. Boll

    Just 2 days ago, it did not look too good, and then there was yesterday. I know now that the official report does not look too promising but the show is not over yet. It is still out there and holding together some how.

  27. Edward M. Boll

    With the official report showing a dimmer ISON, I suppose that currently it is dimmer than the magnitude of -2.8 shown on the ISON tracker.

  28. Edward O'Reilly

    Ison is still playing mind games with us,Bob! It’s been described as a roller coaster-can’t think of a better description! At least it appears to be holding together and not breaking up-which might be the best news yet.We’ll know soon….

  29. Very dissatisfied with total coverage,availability of non nasa web sites,internet overloads,rumors,inbound, now outbound and brightening???. Too much commercialism(Google,U-Tube and the whatever you call it (HANGOUT). With all our tax dollars being spent, you would think that NASA would have done a better presentation on it’s own. Seeing is believing, what we go to see(can it be trustworthy). Very dissatisfied with all.

  30. It lives – it dies or it dies or it lives. The scientific community really needs to get their act together. I guess comets and unidentified flying objects go Hand in Hand. It is strange that the national news media did not pick up on live coverage of Isons event. Some say this was for national security reasons.
    Well just in on the TV “Is on lives” and even a photo to boot. The proof will be in the Dec. night sky, I hope!

    1. astrobob

      I’m guessing Thanksgiving had something to do with no live coverage of the comet. That and its dim appearance on the inbound leg to perihelion. Usually no one watches anything on Thanksgiving but football – ha! I just put together a new guide on spotting the comet in today’s blog. Good luck and let us know if you spot it.

Comments are closed.