Golden Comet Holmes - explanation of no tail? (03Nov2007)

[Sally Smith]

http://apod.nasa.gov/apod/ap071103.html

Got to your kitchen. Get a funnel. Look at the funnel from the side.... think of the small opening as the comet's head and the body of the funnel as the usual "tail" we want so much to see.

Now turn the funnel so you are looking at it straight on from the small end.

Look familiar ?

Isn't it possible that the "Halo" that we are seeing IS the tail ?

Just wondering out loud... I'm no astronomer, but a sculptor who sometimes uses unusual camera angles and perspectives to fool the eye of the viewer. These pictures we are viewing of comet Holmes are 2-D images of a 3-D object and perhaps we are looking right at the tail but can't "see" it because we are expecting it to be a certain way ; trailing out to one side or the other. But if the comets tail is heading directly away from us, the images we are currently seeing could indeed have the tail in plain sight, just not at an angle we are used to seeing.

Is this possible?

8)

[BMAONE23]

Great description Sally. The funnel is a great analogy for a comet and tail.
Much like we only see the outer planets as full or nearly full disks, it stands to reason that we would view outer comets with little or no visible tails as the tails are always pointing away from our vantage point.

[orin stepanek]

http://antwrp.gsfc.nasa.gov/apod/ap071103.html
Welcome to the forum Sally.
Orin

[rollovermikey]

Halloween brought around some friends I haven't had much communication with within the past year. As I sat out in the yard looking for trick-or-treaters, I was able to treat five interested people to the sight of this novel comet through 10X50 binoculars. The great part is that all of them were able to spot it with the naked eye (once I showed them where to look) before looking through the binos. Sidewalk Astronomy at it's best! Might actually get one of them to break out his telescope for an overnight all-sky observing session soon! Just waiting on a good cold front!

Clear skies!
Mike

[TimeTravel123456789]

According to the Atlas of the Universe, the comet was found in 1892. It was not seen again until 1906 and then until the 1960's. The period is like 8 or 7 years however according to that resource. (Found at a local University)

Interestingly, I sent an email on October 21st, 2007 to some resources about how Greek and Roman Myths might reflect actual astronomical realities or structures in the sky. I mentioned that we should see some kind of disc in Perseus because Perseus threw a disc. Then Comet holmes appears. I just thought that strange.

I know this sounds strange but I thought maybe something was trying to help me make the point that systems like guardianship and crime are very similar to slavery. I thought maybe like Perseus, something was trying to help me throw a disc to make the point that we treat wards and criminals and people like slaves like Perseus wanted to free some people (Andromeda his mother Danae) too. Yes irrational, but it is a nice astronomy anecdote even tough of no scientific value.

[NoelC]

Is this possible?

Yes. You are right on, Sally. We're not a long way from being right between the sun and the comet. Note its position in the sky... Highest in the middle of the night, when the sun is straight down (more or less).

Holmes is quite likely a spectacular sight from, say, somewhere in the asteroid belt.

That said, it is (er, we are) off-center far enough that a greenish-blue ion tail is visible just off to the side in very deeply exposed images.

-Noel

[orin stepanek]

Today's APOD: Nov. 5 shows the tail! http://antwrp.gsfc.nasa.gov/apod/ap071105.html
Orin

[Chris Peterson]

Isn't it possible that the "Halo" that we are seeing IS the tail ?

I don't think so. A comet's tail isn't a simple cone, but a complex, structured collection of individual streams. We have simply been seeing the expanding coma. The tail is pointing away from us, and hints of it have been imaged through the coma since a few days of the outburst. In the last few days it has finally become long enough that we can see its foreshortened structure even beyond the coma, on the southwest side where it ought to be.