Fresh Maps To Help You Find Comets ISON And Lovejoy Nov. 10-19

Comet ISON on Nov. 8 from Austria. The bright, long tail is made of dust while the two fainter tails are probably glowing gas called ion tails. Credit: Michael Jaeger

There are now four morning comets visible in 10×50 or larger binoculars from a dark sky site: Lovejoy, ISON, Encke and C/2012X1. The last is the faintest and Encke, while bright at magnitude 7-7.5, is now getting so low, it’s not easy to find for most observers. That leaves us with two reasonably bright targets at comfortable elevations.

What’s this? A comet traffic jam near the Beehive star cluster (top)? Astrophotographer Rolando Ligustri photographed Comet Lovejoy (left) passing the Beehive. At bottom, Comet Lulin made its pass on March 6, 2009. Credit: Rolando Ligustri

A word to the wise – don’t wait too long to see ISON and Lovejoy. The glare of the moon returns to the sky around the 15th and will make both more challenging to find. At the moment Comet Lovejoy is considerably brighter and easier to see then ISON with a magnitude of around 6 versus 8. I even saw it faintly with the naked eye two mornings ago just a finger to the east of the Beehive Cluster.

Updated map showing Comet ISON’s travels through Virgo Nov. 17-21. Map faces southeast and the time is in early twilight about 75 minutes before sunrise. Despite the comet’s low altitude and moonlight, bright Spica and Mercury will help guide you there.  Created with Chris Marriott’s SkyMap program. Click for large version.

So why is Lovejoy so much brighter than ISON the Great right now? Well, it’s much closer to Earth – 42 million miles versus 93 million for ISON. In astronomy, proximity counts. The closer something is, the brighter it looks. There is no better example of this than staring up at the sky on a clear night. Many of the brightest stars achieve that status because they’re closer than the fainter but intrinsically brighter ones.

If you’re not familiar with Virgo’s place in the sky, use this wider-view map that shows bright Mars, Regulus and Arcturus to help point you in Comet ISON’s direction. Stellarium

ISON will hopefully far outshine Lovejoy as we move into late November when the comet get a heavy-duty broiling from the sun. It will pass nearest Earth on Dec. 27 at a distance of 40 million miles. By then Lovejoy will have receded to ISON’s current distance of 93 million miles. Interesting that they they’re moving counter to one another this way.

Comet Lovejoy travels from Cancer across Leo and Leo Minor between now and Nov. 19. The map shows the sky facing south around 5:30 a.m. CST. Stars are labeled for reference. 21 LMi is 21 Leo Minor and 55 UMa is 55 Ursa Major. Stars shown to mag. 6.5 with brilliant Jupiter at upper right as your guide. Created with Chris Mariott’s SkyMap program. Click to enlarge.

While Lovejoy will continue to brighten and could reach 5th magnitude, ISON could become MUCH brighter. The latest estimates have it at the same brightness as Venus (-4 magnitude) for a few hours when it’s closest to the sun on Nov. 28.

The best time to view both comets is right before the start of morning twilight or about 1 3/4 – 2 hours before sunrise. You can click on the charts to get higher-resolution versions of them to print out for use outdoors. Good luck on your comet quest!

19 Responses

  1. frank leppa

    Thanks info yesterday, Bob. Saw Lovejoy, just a blur east of Cancer, thru an opening in the clouds with binos.. regards, frank k0ii

  2. Norman Sanker

    Hey Bob,

    I saw something I thought Comet Encke right around first light yesterday morning. I was about ready to give up as I could see a little hint of dawn along the horizon but I gave a few more sweeps and there it was. Close to a faint star which was in sharp focus, it looked just like a dim globular cluster. I quickly grabbed a higher power eyepiece but the scope slipped when I put it in and I could not re-find it. In 40 plus years of star gazing, I had never seen this most frequent visitor of the periodic comets. This AM, I was able to find it again and take my closer look, so: 3 down and only LINEAR to go. I’m not confident I’ll find that one but I have hope. At least I know when I’m looking at Arcturus so there’s a start. Has it dimmed too much to find and what’s its prognosis as it approaches the sun?

    Norman Sanker

    1. astrobob

      Hi Norman,
      Great work on finding Encke – it’s low! Your description is exactly how I saw it in my scope. Not sure what the prognosis is for LINEAR X1 but it’s presently around mag. 9 but large – about 12 minutes across. I saw it easily in my 15-inch with a somewhat condensed coma two mornings ago. It was also visible faintly in my 10×50 binoculars (I was under dark skies). Good luck!

  3. Giorgio Rizzarelli

    Hi Bob, speaking of comets.. why does Heavens-Above list brightness values much larger (fainter) respect the magnituds that you or the Yoshida site report? Is it a different scale? or because it’s diffuse objects?

    1. astrobob

      They’re basing their brightnesses on the date of the last reported observation. Most of the observations have not been updated – for whatever reason.

      1. Sean

        calsky’s are consistently brighter with the most notable comets – not sure if this means they are updated more often or based on predictions rather than observations.

      2. Giorgio Rizzarelli

        @Bob: I thought that, but they’re updated yesterday… Lovejoy 10.5, Ison 11.8 … check the site. It’s not much a problem (I go on Yoshida site) just a curiosity. Maybe it’s a different way because they’re diffuse, like it measures not only false nucleus but tail also. When you said you spotted Lovejoy naked eye (at <6), did you see also the tail? Btw bad weather here…

        1. astrobob

          Yes, they’re more closely updated today compared to when I last looked but still very faint. Either they’re updating from an old database that doesn’t take into account what’s been happening to the comets at the current time or those magnitudes are m2 mags or nuclear magnitudes. If you’d like I can ask Chris Peat, the fellow who runs the site.

          1. Giorgio Rizzarelli

            I’d appreciate if you can ask, and it may useful for him to clarify, it’s a great site to use for reference.
            I did a bit of research around about m1&m2 and here’s what learned (correct me if I’m wrong).. m1 (integrated or observed magnitude) is measured by defocusing and comparing with a near star, while m2 should in theory refer to the true nucleus but in practice (since amateur instruments cannot see true nucleus) to the false one, and is problematic because depending on magnification. When you report a comet observation, which mag do you mean and how do you estimate it? Thanx!

          2. astrobob

            Almost no one reports m2 nuclear magnitudes. The ones seen almost everywhere are m1 or integrated magnitudes. I did ask Chris in an e-mail earlier today. I’ll let you know as soon as I hear back from him.

          3. astrobob

            Hi Giorgio,
            I don’t know if you got my e-mail about Christ Peat. I wrote him about the bad magnitudes and he updated from the Minor Planet Center database (the low mags.) to the ICQ database which gives more accurate current magnitudes.

  4. Sean

    Bob just wanted to let u kno thx 4 contacting Chris. I have contacted him b4 at least once regarding technical difficulties and at least once with a more general ? but never really thought to ask him about the comet discrepancies. Thanks to u and Giorgio it seems we will have more accurate mags, at least 4 some of the comets, from now on. Hopefully.

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