Comets along the ecliptic?

What percentage of known comets orbit the sun along(or nearly along) the
ecliptic?

Along the same lines--what areas of the sky do comet hunters focus on in
searching from the Northern Hemisphere?

Thanks,

tM

If you mean have orbits that line up along the ecliptic as the planets so,
practically none, meaning the vast majority of discovered comets have orbits
tilted in every direction.

--
Sincerely,
--- Dave
----------------------------------------------------------------------
It don't mean a thing
unless it has that certain "je ne sais quoi"
Duke Ellington
----------------------------------------------------------------------

"themeanies" wrote in message
...
What percentage of known comets orbit the sun along(or nearly along) the
ecliptic?

Along the same lines--what areas of the sky do comet hunters focus on in
searching from the Northern Hemisphere?

Thanks,

tM

On Thu, 13 Jan 2005 20:45:51 -0600, themeanies
wrote:

What percentage of known comets orbit the sun along(or nearly along) the
ecliptic?

The graph (Fig. F5) on page 205 of "The Cambridge Guide to
Astronomical Discovery" (1992, by William Liller) shows the
inclinations of the orbits of all comets with well-determined orbits.
The bar graph uses different cross-hatching for long-period and
short-period comets.

The short-period comets show a definite and strong preference toward
zero degrees.

The long-period comets are more numerous at inclinations from 45 to
155 degrees than they are from 0 to 40 degrees.

Along the same lines--what areas of the sky do comet hunters focus on in
searching from the Northern Hemisphere?

Before the automated search programs (such as LINEAR), comet hunters
concentrated their searches in the dark sky nearest the sun -- just
after the end of evening twilight and just before morning twilight.
Odds were somewhat better in the morning sky.

After the advent of the automated search programs . . . I'm less
knowledgeable; but IIRC Don Machholz has mentioned that he checks for
the areas not yet covered by the automated searches and makes those
areas a priority. (In the realm of comet hunting it's always been
advisable to know your competition.)

By the way, there are many more graphs and other information relating
to comet discovery in Liller's book. Despite the HUGE effects the
automated programs now have on comet hunting and discovery, I think
you would find Liller's book useful.

Who knows, one of these cold, dark nights I may return to my own old,
moldy, comet-hunting program.

OTOH, when I make sketches during an observing session I tend to
return indoors with something to show for my time under the stars ;-)

Sketcher
To sketch is to see.

Before the automated search programs (such as LINEAR), comet hunters
concentrated their searches in the dark sky nearest the sun -- just
after the end of evening twilight and just before morning twilight.
Odds were somewhat better in the morning sky.

After the advent of the automated search programs . . . I'm less
knowledgeable; but IIRC Don Machholz has mentioned that he checks for
the areas not yet covered by the automated searches and makes those
areas a priority. (In the realm of comet hunting it's always been
advisable to know your competition.)

By the way, there are many more graphs and other information relating
to comet discovery in Liller's book. Despite the HUGE effects the
automated programs now have on comet hunting and discovery, I think
you would find Liller's book useful.

Who knows, one of these cold, dark nights I may return to my own old,
moldy, comet-hunting program.

OTOH, when I make sketches during an observing session I tend to
return indoors with something to show for my time under the stars ;-)

Sketcher
To sketch is to see.

What a fantastic response. Thank You.

tM

Sketcher wrote:
The long-period comets are more numerous at inclinations from 45 to
155 degrees than they are from 0 to 40 degrees.

Do you mean per degree density of comets, or cumulatively?

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

Sketcher wrote:
On Thu, 13 Jan 2005 20:45:51 -0600, themeanies
wrote:
snip

[Stekcher]
[b]ut IIRC Don Machholz has mentioned that he checks for
the areas not yet covered by the automated searches and makes those
areas a priority.

How does one determine what areas are currently covered by automated
searches? - Canopus56

On Mon, 17 Jan 2005 02:31:56 +0000 (UTC), (Brian Tung)
wrote:

Sketcher wrote:
The long-period comets are more numerous at inclinations from 45 to
155 degrees than they are from 0 to 40 degrees.

Do you mean per degree density of comets, or cumulatively?

Good question! Thanks for pointing out a necessary point of
clarification:

The graph shows a pair of vertical bars for each 10 degree interval,
one bar for short-period comets and one bar for long-period comets.
The height of the bars represent the number of comets with orbital
inclinations that fall within each ten degree range.

The shortest of the twelve long-period comet bars in the 40 to 160
degree range is taller than the tallest of the four long-period bars
in the 0 to 40 degree range.

Another clarification: The sentence quoted above (although correctly
quoted by Brian) should have 45 changed to 40 and 155 changed to 160.

Sketcher
To sketch is to see.

On 16 Jan 2005 18:53:43 -0800, "canopus56"
wrote:

How does one determine what areas are currently covered by automated
searches? - Canopus56

It's my understanding that the following link can be used for this
purpose:

http://scully.harvard.edu/~cgi/SkyCoverage.html


Sketcher
To sketch is to see.