Obscure Comet Brightens Suddenly

Here is an image that I think is very close to true color.

It has an yellow/orange cast to it and this photo also shows a green halo around it.

Taken by: Chris Schur, Payson, Arizona Oct. 24, 2007



Posted at: www.spaceweather.com...

[edit on 10/26/2007 by Hal9000]

I seem to recall that when Haileys comet came by last it was said to have brightened unexplainably as it left. Astronomers were wondering if it had collided with something. Anyone else remember that?

An astronomer near San Francisco, this morning on the radio said that he did not know why the comet was brightening.

He suggested that due to the position of the comet with respect to the Earth and the Sun, that we would not see a tail, as it would be facing away from us.

If that is true, we could be missing alot of this event due to our view.

He then speculated that it might be a highly reflective object and suggested that it might be the opposition of the sun, earth, and comet itself which is causing the brightened view. He speculated that perhaps the comet is highly reflective, and we are catching a sun glare.

An interesting event. Thanks for the post.

[edit on 26-10-2007 by Ectoterrestrial]

I'm sorry if this is a stupid question. If this comet has no tail, doesn't it mean that it's heading straight towards us?

Hellmutt

Yep, lack of tail can mean just that.
Sometimes the tails are just faint, too.
Right now we are ROUGHLY aligned between the comet and the sun.
The coma, as big as it is might be obstructing part of the tail..


It's really easy to spot!
I was able to spot it in about 10 seconds.
Even snapped a photo with my camera, just a few minutes ago.

reply to post by Hellmutt

From what I gather, the comet had no tail because it wasn't producing any out gas, and now that it has increased in brightness and is producing out gas, some are speculating the tail is moving away from us, so we can't see it.

The thing about comet tails is they are always going away from the Sun. The Sun's solar wind blows the comet dust particles away from the sun, so it doesn't always follow behind the direction the comet is headed like it would on Earth in an atmosphere. It is possible that the tail and the comet are heading in the same direction. Here is a good example of the tail of a comet.



From the orbital data I've seen, I don't buy the idea that we can't see the tail because it is behind the comet. I think it takes time for it to develop now that it is producing out gas.

What is interesting about this comet is everyone is wondering what may have caused the increased brightness. It could be that it was hit by an asteroid or something and may be breaking up which would explain the increased brightness. So everyone will be watching it for the next few days to see if there is any change in it's shape. If the shape changes then it is probably breaking up. If not, then another explanation for the increased brightness is needed.

For Astronomers this is a big event, because they hope to learn about the life cycle of these objects. If the comet is breaking up, it is near the end of its life cycle, then the death blow just occurred right in front of our eyes. To witness something like this is like a football fan being able to witness the Hail Mary, or the impossible touchdown pass. It could be a lifetime event and is a big deal for those that are interested.



[edit on 10/27/2007 by Hal9000]

The alignment right now is not the best for seeing an ion tail.

You can run the simulator here ssd.jpl.nasa.gov...

It's above the ecliptic, but we're aligning ourselves between us and the sun.
That lasts for a few weeks, then we'll lap it's orbit.

There may be more surprises though. It may grow as large as a full moon, or it may run out of steam tomorrow.
That's comets for ya!

reply to post by spacedoubt

After looking at the orbital diagram closer, I guess we are pretty close in alignment from the Sun, so the tail will be hard to see, so I will concede.

That still doesn't change that the comet has increased brightness by estimates ranging from 400,000 to a million times brighter. It is a periodic comet and has increased in brightness before, but something tells me this is a rare event, and one in which it will be interesting to see what the experts come up with.

Time will tell. Thanks for the input.

And I thought we were pretty much in agreement already..

Have you had a chance to spot it Hal9000?
I was surprised that it took no time at all.
Great view through 10x binoculars too!

Next few days will be telling. I'd love to see it brighten up for everyone to see.
We're sort of moving straight at it for a while, so it won't move much in the sky,
making it easy to locate night after night.

I love this stuff!

Originally posted by spacedoubt
And I thought we were pretty much in agreement already..

I was conceding the part about the tail. I originally thought if it did have a tail we would be able to see it, but others such as yourself said we may not because of the orbital alignment so the tail is hidden behind the comet. I used the orbital diagram you posted and turned it around viewing behind the comet and now agree Earth is close to alignment of where the tail could be behind the comet. That orbital diagram program is a great for learning about this stuff.

Originally posted by spacedoubt
Have you had a chance to spot it Hal9000?
I was surprised that it took no time at all.
Great view through 10x binoculars too!

Yes, I mentioned earlier that I spotted it in my binoculars, but now it is cloudy again in my location. It looked like just another star naked eye, but when using binoculars it looked like an orange fuzzy ball. I hope to get a clear night to be able to setup my telescope and take some images.

Originally posted by spacedoubt
Next few days will be telling. I'd love to see it brighten up for everyone to see.
We're sort of moving straight at it for a while, so it won't move much in the sky,
making it easy to locate night after night.

I love this stuff!

I think everyone into astronomy will be watching this comet to see what happens. I think there was a collision and it may break up. This event reminds me of other previous discoveries I have read about, and it is exciting to witness it as it unfolds.

Whatever happened up there must have been catastrophic. A collision perhaps, but a break up of the nucleus due to gravitational forces and/or heat from the sun is more likely I think.

Have a look at these stunning images Richard Crisp captured using polarized filters, showing previously unseen detail in the coma:

www.narrowbandimaging.com...

There is a neat animation there too if you scroll down a little.

I set my telescope up and was able to take some images of the comet in between the clouds and I think I see something happening. I see a bright spot off center of the nucleus that I think may indicate the nucleus is breaking up.



I can also see this in the eyepiece so I don't think I am seeing things. I am now recalibrating my camera and I will take some more images and see if it is still there.

Edit: I re-calibrated the camera and got the same image. I am now trying a different camera to see if I see the same thing.

[edit on 10/28/2007 by Hal9000]

Well it has been confirmed that there is a bright spot near the comet which appeared on my image. It could be a background star or it could be the nucleus breaking up. I haven't seen any other image posted similar to this, but another member of my club said he saw the same thing. Here is another image taken with a monochrome camera.

I found other similar pictures from a photo gallery.

Comet Holmes Photo Gallery Page 3

From the descriptions, they are saying the bright spot is the nucleus core of the comet and not a piece of it. It is still increasing in brightness.

Comet Holmes Photo Gallery Page 4

It looks like the comet is breaking up. There are now definitely two, maybe three pieces.

Correction:

Well I have heard from several sources now that the comet is not breaking up. The bright spots are actually background stars shining through the coma.

Contrary to appearances, the core of the comet has not split in two. The two eyes are an illusion caused by background stars shining through the comet's gaseous envelope

www.spaceweather.com...

Nope. Comet Holmes is not breaking up. The comet was just passing by a pair of faint background stars. According to Starry Night Pro 5.0, the star to the right of the psudonucleus is TYC3334-788-1 (mag. 9.21) while the fainter one below it is TYC3334-738-1 (mag. 10.84).

www.spaceweather.com...

Originally posted by Hellmutt
I'm sorry if this is a stupid question. If this comet has no tail, doesn't it mean that it's heading straight towards us?

No, actually the tail is not the direction of travel. The tail is generated by solar winds so can be at a 90 degree or more to direction of travel. The tail, if it exists always points to the sun.

Also depending on the distance to the sun a comet will not produce a tail until close enough. Holmes might produce a tail as time goes on.

Also I said Holmes might have hit an asteroid in the belt between Mars and Jupiter. You need to know how unlikely that is. The density of the asteroids in the belt is so diffuse that it is more like a teaspoon of talcum powder spread over an area the size of Earth. Otherwise as the plane of the solar system goes over we would see obscuration of objects in deep sky and planetary observing. That does not happen, so there you can see why.

ZG

Originally posted by Astyanax
Fusion drive kicking in for sublightspeed manoeuvring, obviously.

What else could it possibly be?

You may have offered this as a joke, but I immediately thought of the same thing - that all this is all being observed because it's not a comet.

A tail visible only in the infrared and not pointed away from the sun like all other comets. I was thinking some sort of drive plume when I read about that.

Maybe a bunch of people's wishes are about to come true?

Really nice photos Hal9000!
Could you let me in on how those were taken?

MY single photo, was just a 300mm lens on a DSLR with a tripod.
iso 800
8 second exposure.

Tonight it's raining though

reply to post by spacedoubt

Sure, I took these with a Meade 8" LX200 Classic telescope, with a .63 focal reducer, using a Meade DSI Color CCD Camera. I am using the Envisage software in Meade's Autostar Suite which comes with the camera. It has a built in guider to align and stack the images and it even does a good job on the color balance.

I have just started taking images and can do bright object pretty well, but nebulas are being elusive. I am surprised at how easy this comet is to photograph. It's very photogenic.

Anyway here are some new images that I just took tonight. The seeing wasn't as good as the last two nights and the Moon was coming up, but I managed to take these.

This one was a repeat from last night taken with the 8" LX200 and all that can be seen now is the comet nucleus. The previous bright spots were background stars that the comet has moved away from.



This one I used a Stelarview 80mm Nighthawk II refractor telescope with the DSI Color camera. I wanted to try to get a better exposure of the whole coma. This is the first image I ever took with this telescope.



I think it came out pretty good.

Enjoy.