After days of dreariness, we finally got clear skies for some hours.

Comet is clearly visible to the naked eye, and clearly extended too!! Very great view through binoculars, it has become quite large.

I attach a crappy wide-angle picture taken with my little digital camera (8 seconds, ISO 400, 50% size and strong JPEG compression...). It seems to be brighter than Delta but fainter than Alpha, so about mag 2.1.

We also got 2 x 20 minutes high resolution echelle spectra with our 2m telescope. While the comet seems bright to the eye, the surface luminosity is already very low, in our seeing, it's similar to a 14th magnitude star!! Therefore the spectra are not really high signal-to-noise, but hopefully we'll get something out of them. A lot of absorption and some emission lines are seen in the raw spectra.

Looking forward to waning moon vs. halo expansion.

Sometime next week, we'll take images with our big telescope.

Attached Images

Comet_Holmes_small.jpg (138.7 KB, 27 views)

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David Alexander Kann
PhD student, Gamma-Ray burst Afterglow Collaboration at ESO
Thueringer Landessternwarte Tautenburg

<span style='color:blue'>Ignite our minds and let's burn brighter
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<span style='font-size:8pt;line-height:100%'>- Dark Tranquillity, The Wonders At Your Feet</span>

I finally saw the spectacular outburst from the periodic comet 17P/Holmes on Saturday night through my 15x70 Burgess Optical binocular. However, before I could set up my 80mm f/5 Orion ShortTube 80 achromat, clouds began to move in from the west. Since the forecast was for clear skies, I went back into my brother's house to watch the end of the first half of the disastrous Penn State game and a bit of the World Series. Unfortunately, every time I went outside to check on the conditions it was overcast. When I finally went to bed around 2:00 a.m., it was still cloudy.

It was obvious after looking at the comet for a period of a couple of hours on Sunday night that the three other "pseudonuclei" (two of which were rather faint) that I could see through the ASH 17" f/15 classical Cassegrain at magnifications of 162 (40mm University Optics MK-70), 202 (32mm University Optics Koenig-II), and 259x (25mm University Optics MK-70) were merely field stars.

17P/Holmes also exhibited a bright inner and a faint outer coma as well as a fan-shaped area of ejecta extending southwestward from the true pseudonucleus, which appeared distinctly non-stellar at higher magnifications. I estimate that the outer coma subtended approximately 7 arc minutes. To the naked-eye, the comet seemed to be slightly less bright than Algol.

I also observed the comet through a fellow ASH member's 12x36 Canon IS binocular, my 15x70 Burgess Optical binocular, my 80mm f/5 Orion ShortTube 80 achromat at 15 (26mm Tele Vue Ploessl) and 57x (7mm Nagler Type 6), the ASH 4.25" f/4.2 Edmund Scientific Astroscan (28mm Edmund Scientific RKE and 13mm Tele Vue Ploessl), the ASH 5" f/5 achromatic finder scope (32mm no name Erfle and 13mm TV Ploessl), a fellow ASH member's 10" f/10 Meade LX200 SCT (36mm Meade QX, 28mm Edmund Scientific RKE, and 26mm Meade QX), and the ASH 14" f/10 Meade LX200GPS SCT (55mm University Optics Ploessl and 36mm Meade QX) during the course of the evening.

The yellow hue that 17P/Holmes is exhibiting was most evident through the 80mm ST80 at 15x. The best overall view was through the 17" at 162x. A brighter view at 118x (55mm University Optics Ploessl) was also quite nice as was the view through the 14" SCT at the two magnifications used.

The image posted at http://www.princeton.edu/~rvdb/image...mes-SumAll.jpg illustrates the comet's motion and is quite similar to what I saw visually through the 17".

This historic cometary outburst is providing some absolutely unique views and is yet another of the unexpected events that add spice to amateur astronomy.

Dave Mitsky

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Apparently, the two stars near the true pseduonucleus (is that an oxymoron?) were GSC0333400738 (magnitude 10.9) and GSC0333400788 (magnitude 8.7).

Dave Mitsky

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I'm starting to think I shouldn't have waited for my weekend before I set up the scope to have a look at this bad boy. Hopefully it'll hang in there until tonight. I'll put off my weekend beer binge and set up the scope. I dare not wait for Tuesday.

Unfortunately I forgot to print any charts at work so I'll have to use my snail slow home printer. Wish I hadn't broke my laptop.

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Finally, last night we had clear skies. Mrs. Swift and I went out with the binocs and the spotting scope and found it pretty easily. Great views, could clearly see the little fuzzy blob in both the scope and the binocs. Made my night.

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Must be pretty bright if the best way to see it is through sunglasses



--seriously - any photos?

We don't know...yet!
Maybe an explosive out-gassing.
Maybe a meteoroid or asteroid impact.
Maybe LGMs taking target practice. j/k

This is not the first time this comet has done this. It was discovered in 1892 when it suddenly increased in brightness by several hundred thousand fold!

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T. Anderson

Since there are already a number of threads on this, I thought I would put my question here. Are there any spacecraft planning or working at imaging Comet 17/P Holmes ? I have been wondering what the outburst might look like from another angle ? Then I noticed in the BA's Blog which is linked to in this thread, that Phil said something like, "it might not be a shell of debris but a jet of material pointing towards or away from us". It seems like an image from Cassini or New Horizons would be able to answer that, and would be very interesting anyway. Are there any other spacecraft that could give us an image from a sufficiently different angle.

I would bet that some spacecraft team is working on this, and we will be seeing a great APOD image any day now.

wOw

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The pictures on that website are just beautiful...this is my favourite comet since Hale-Bopp

17/P seemed a little fainter tonight; whether that's because of a more extended envelope spreading its light over a larger area, or a true intrinsic drop in brightness, I've no idea. In any event, in spite of a lower, waning Moon, it seemed only incrementally brighter than Delta Persei tonight.

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I had me a good look tonight. The seeing seemed better than normal. I even saw a few galaxies and I've never seen one, except Andromeda, before tonight. However I suspect it was actually due to inadequate alignment. I guess I'll have to verify my findings next time.

Anyway, el Comet was pretty cool. Easy to find in the spotter. I just GOTOed to ngc 1491 and slewed up a bit and there it was, in the spotter. Big and round and fuzzy.

And so I showed it to the wife. I told her it was a comet. She heard Andromeda I guess because that's what she told the kids to come see. I told them it was a comet. They still didn't seem impressed. They weren't impressed when I showed them Andromeda earlier either. I guess they expect hubble pictures or something. Oh well, I thought it was cool...as was Andromeda.

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I agree. It seemed fainter and more spread out. It was nice seeing it while also observing an Iridium flare over near Cassiopeia.

BTW, those "pseudonuclei" are without a doubt the spacecraft that are using the comet as a decoy as they ply their way into the inner solar system. There should be more information on this from California shortly.

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The cloud cover conspiracy ended! I was finally able to get a look at it through some binocs.

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I heard it on the news just the other day
There's this new stuff called dark energy
We can't measure and we can't see..." - from Jimmy Buffett's What if the hokey pokey is all it really is about?

wow! ive been so out of it and i was looking at planets tonight and i saw this thing in perseus and said 'that isnt right' and got kinda scared and thought it was a comet real close and fast then was relieved it was 17P!!!

The coma of 17P/Holmes is now larger than the Sun!

http://www.cloudbait.com/gallery/comet/holmes.html

__________________
Chance favors the prepared mind.
De gustibus non est disputandum.
Never attribute to malice that which can be adequately explained by stupidity.

I went out with the binocs for one last look but the clouds have set in. The only thing visible was the moon. Well, maybe it'll clear up. The weather has been really cooperative around here lately. That may be at an end now though.

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You're a coward and a liar and a thOOF - Bart Sibrel

There are so many comet Holmes threads, I wasn't sure where to post this question. To my eyeballs, it looks a little dimmer to the naked eye, but it is still easily a naked eye object, even with my mediocre suburban skies. It also looks a little dimmer to me in the binocs, but even in those you can tell it is larger. I have wondered if it looks dimmer because it is spread out over a bigger volume? Does anyone agree with this observation?

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At night the stars put on a show for free (Carole King)

I think that is normal as it gets more diffuse. To me it looked dimmer in my central vision, but in averted vision, which made the stars fuzzy, it still was a pretty good match for the 3rd magnitude stars.

I got my first look in over a week.
1) It's a lot bigger than it was!
2) It doesn't seem to have changed much in brightness either way.

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Any day you wake up on "the right side of the dirt" is a good day.

T. Anderson

I have to bump this one since this is the p17 holmes thread I've been using and I'm not sure which one is the favorite comet thread.

I went out for one last look tonight. This time I mean it. I could hardly make it out in my 7x35s. Just a fuzzy spot, although a really big one.

Anyway, comet p17 Holmes, thingy see you in 6.882994 a whatever that is...

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You're a coward and a liar and a thOOF - Bart Sibrel