Date   

Re: Asteroids III

Brian D. Warner
 

James,

Thanks for the update. That space on the shelf next to Asteroids II
will soon be filled.

Clear Skies,
Brian Warner


Asteroids III

James McGaha
 

I just spoke to University of Arizona Press about Asteroids III,
the warehouse arrival date has slipped to 1 March.
It will ship 3 March at earliest.
(assuming they get it on 1 March)

James McGaha
651 & 854


The Infinite Minor Planet Game

Edwin Goffin <edwin.goffin@...>
 

Dear all,

The discussion about the origin of the phrase "Vermin of the Skies" reminds
me of another one (see subject) whose origin is equally mysterious to me.
Somewhere I got the idea that it originted with Lobus Kohoutek. Long ago
(15 years or so) I wrote him a letter at the Hamburg Observatory, but never
got an answer.

Edwin


Re: {MPML} LSST and follow-up

James McGaha
 

Brian Skiff wrote:

A conference paper appearing on the astro-ph server tonight might
stir some speculation about faint asteroid discovery and follow-up:

http://xxx.lanl.gov/abs/astro-ph/0302102
Large Synoptic Survey Telescope: Overview

To the extent that the numbers given are pie-in-the-sky (ahem), one would
conclude that the follow-up part comes automatically, since the sky is
covered often. The notional magnitude limit of 24 suggests the _bright_
limit will be about 17th, so the brighter NEOs (for instance) will simply
not be observable/follow-able with this telescope.

&#92;Brian

What I love the most is the phrase :
"Curiously, all these projects make use of the same data : short
exposures in multiple filters."
Why the heck do you need filters for asteroid detection, except from
loosing limiting magnitude. What about a 4 meter only telescope,
specifically for NEA searches, without any filter, much cheaper, same
throughput... Unless the project is really a cosmological project
disguised in a "save the world from bad asteroid" program....
:-)
Alain


Anyone who believes the LSST was to have a major role in asteroid studies
of any kind, I have a bridge, I would be happy to sell you. The "Asteroid Project"
was a political ploy put on the project to help it get funded. Professional Astronomers
(that is most of them) do not care one bit about asteroid research.


James McGaha
651 & 854


Ephemeris uncertainty

Bill J. Gray
 

Steve, Ted, many thanks for the comments on this. I've
grabbed and read Ted et. al.'s _Asteroids III_ article; between
that and the on-list comments, I think I've got a much better
handle as to how this sort of thing ought to be done, as well
as a lot of nifty ideas to sort through.

Lest others on this list wonder why I'm yakking at length
about some rather theoretical/mathematical problems, I should
probably explain that I have a very practical purpose:

My hope is to produce something that will make ephemeris
uncertainty computation an easy, routine thing for observers.
There have been a lot of inquiries on this list along the lines of
"OK, I've observed the object on two nights, just as MPC wants me
to... or when should I observe it next?" Or, "I've covered it for
X days; how long should I wait before going after it again?"

The usual answer is, "Wait until its ephemeris uncertainty grows
a bit; you want it to be large enough to be interesting, but small
enough that you can recover it without too much effort." That's a
great idea in theory, but I wonder how many people actually run
OrbFit to find out what the current ephemeris uncertainty is for
their target? (Or look at the ASTORB database... which gives just
an uncertainty _distance_ and no "shape" data?)

Anyway, if I write the sort of tool I'm aiming for, people will
be able to easily say, for example: "Gee, that object is still
nailed down to within 1 arcsecond. No need to waste time imaging it
tonight." Or, "Wups! Its positional uncertainty is about as big as
my field of view... better go after it, and hey, the program is
showing me the line along which I ought to find this object."
It will (I hope and expect) be very straightforward to use.

So far, I've added code to Find_Orb so you can push a button
and watch as it repeatedly adds noise to the original observations,
re-solves the orbit, and shows new elements. It does it over and
over, generating new element sets to add to a file. I still gotta
write some code so you can then see the predicted positions plotted
out on a chart. This is the method I originally proposed, #3 on
Steve's list, "Observational Monte Carlo". I'm not going to throw
it out, but the comments made thus far are making me consider
revisions and extensions.

Method #4, "Statistical Ranging", is something I tried a while
back (for orbits of irregular satellites) and should probably try
again. Like #3, it's got the advantage of being a relatively
simple, "physical" model. (I'm not much of a mathematician, so
I prefer these methods that can be understood in terms of physics.)
Seems to me a combination, in which variations in both ranges _and_
the observed RA/decs, may be important in some cases. David
Tholen's comment that it helps ensure you get both solutions
"resonates" with me, especially since I've had one embarrassing
case where I found two solutions and the object turned out to be in
a _third_ (again, an irregular satellite).

Steve, at the risk of opening a can of worms... I just read a
bit about the semi-linear method in Ted et. al.'s article, and it
actually looks like a variation on something I've done from time
to time over the years, in a less formal way. Often, when solving
a TNO/distant object, I'll set a constraint such as requiring q=30,
or P=248 (for a Plutino), then do the usual least-squares fit for
the remaining five parameters. I'll then start wondering what range
of P (or q, or a, or e) will lead to "reasonable" orbits, so I'll
start trying q=31, q=32, etc., until the residuals or the orbit
gets ugly; then I'll try q=29, 28, etc. Eventually, I've "mapped
out" the range of likely values of q.

If I'm understanding the article correctly, the resulting
slew of orbits can be considered to show the uncertainty region.
I rather like this idea, since it is also a straightforward
extension of code I've already written (and again, it makes some
"physical" sense.) However, this actually doesn't sound too
hard to do. When things look that easy, I start assuming that
I've missed something.

-- Bill


Re: {MPML} LSST and follow-up

Alain Maury <amaury@...>
 

Brian Skiff wrote:

A conference paper appearing on the astro-ph server tonight might
stir some speculation about faint asteroid discovery and follow-up:

http://xxx.lanl.gov/abs/astro-ph/0302102
Large Synoptic Survey Telescope: Overview

To the extent that the numbers given are pie-in-the-sky (ahem), one would
conclude that the follow-up part comes automatically, since the sky is
covered often. The notional magnitude limit of 24 suggests the _bright_
limit will be about 17th, so the brighter NEOs (for instance) will simply
not be observable/follow-able with this telescope.

&#92;Brian
What I love the most is the phrase :
"Curiously, all these projects make use of the same data : short exposures in multiple filters."
Why the heck do you need filters for asteroid detection, except from loosing limiting magnitude. What about a 4 meter only telescope, specifically for NEA searches, without any filter, much cheaper, same throughput... Unless the project is really a cosmological project disguised in a "save the world from bad asteroid" program....
:-)
Alain


LSST and follow-up

Brian Skiff <brian.skiff@...>
 

A conference paper appearing on the astro-ph server tonight might
stir some speculation about faint asteroid discovery and follow-up:

http://xxx.lanl.gov/abs/astro-ph/0302102
Large Synoptic Survey Telescope: Overview

To the extent that the numbers given are pie-in-the-sky (ahem), one would
conclude that the follow-up part comes automatically, since the sky is
covered often. The notional magnitude limit of 24 suggests the _bright_
limit will be about 17th, so the brighter NEOs (for instance) will simply
not be observable/follow-able with this telescope.

&#92;Brian


Re: {MPML} Monte Carlo uncertainty estimation

Steve Chesley
 

Bill,

There are roughly five means of mapping an orbital solution with uncertainty to a given time, each with a fairly well defined realm of utility.

1) Linear covariance mapping. Take the covariance that you get (or should have gotten!) from the least squares orbit solution and map this to the time and reference frame of your choice via the state transition matrix, which is usually obtained by integrating the variational equations but can also be computed with finite differences. This is not for the faint of heart when it comes to impenetrable jargon, but is really not as complicated as it might sound.

Linear methods are appropriate when the uncertainty is "small." Typically, when uncertainties become on the order of a degree on the sky or become a substantial fraction of an AU in space this method falls apart. This failure can usually be traced to a weak orbit, a long propagation, a very deep close approach, or some combination of these. Multi-opposition and radar-astrometry orbits are almost always amenable to this approach.

2) Orbital Monte Carlo. When the orbit itself is fairly good, meaning that the uncertainty region is small enough that it really looks like an ellipsoid (not a banananoid) in orbital element space, but the propagation is substantially nonlinear then Monte Carlo (MC) sampling in element space is the way to go. This amounts to adding noise that is consistent with the covariance matrix to the nominal orbital elements. Do this many times and you get an ellipsoidal cloud of points in space around the time of the observations. Andrea Milani likes to call these "Virtual Asteroids" because the real asteroid could be represented by any of the Monte Carlo samples. Now if you propagate all of the MC points to the time of interest the cloud will eventually deform to look like a banana after many revolutions or like a corkscrew if there is a close planetary encounter. Any nonlinearities stemming from the propagation (close encounters, Keplerian shear, etc.) will be handled properly by this method. This method is very simple to implement, but requires a good deal of computer horsepower relative to the linear method.

For NEAs orbital MC sampling is usually appropriate when the observed arc is a few weeks or more.

3) Observational Monte Carlo. When the observed arc is very short the uncertainty in the original orbit determination is so large that you cannot assume that the ellipsoid represented by the covariance adequately represents the true uncertainty. Monte Carlo sampling can still be done, but this time noise must be added to each of the observations and a new orbit computed based upon the revised observations. This new orbit becomes a Virtual Asteroid as above. The drawback is that you have to solve the least squares problem for every single MC orbit with this approach, which can be time consuming, and so the MC sampling process is far slower. This can be a big deal if you are running many millions of orbits, but in practice the time spent propagating each sample is long relative to the MC sampling time, and so the propagation time is what limits your ability to take a lot of samples.

This method is what Bill describes and is, I understand, already a part of John Rogers' CAA software. It is generally suitable for NEAs with at least a few days of observations if the least squares problem is convergent. If there are distant alternate solutions, as often happens for short-arc objects discovered near-sun, this method is _unlikely_ to reveal those alternate solutions.

4) Statistical Ranging. This is really the only reliable means of computing orbits with very short arcs, ranging from a few minutes to a few days. This approach is also Monte Carlo in style, but it randomly samples two observations from the available set and selects two random topocentric distances at the observation times. From two obs and two distances you get an orbit, and that's your Virtual Asteroid. There are a host of variations on this method: You can also add noise to your sampled observations if you like. Dave Tholen and Rob Whiteley, working independently from Virtanen et al., have implemented a method that fits an orbit to all the available observations with the topocentric distance constraints applied. Or something like that.

Statistical ranging _will_ reveal alternate solutions and will give robust uncertainty regions, which in some cases can be really wild looking.

5) Multiple Solutions. This is the method popularized by, if not invented by, Andrea Milani. It maps the spine of the elongated uncertainty region at epoch, and so it is a one-dimensional sampling, which substantially cuts the CPU requirements. But it is perhaps the most complicated of the methods, and I'm starting to realize this message is going far too long, and so I'll only say that this method is at the core of both of the automatic impact monitoring systems currently in operation (Sentry & NEODyS). Objectively this approach has a pretty limited utility due to its complexity.

Each of the above methods has a fairly specific region where it is the most appropriate, but there is still a good amount of overlap. Methods 1-4 can be viewed as providing increasing power at the expense of simplicity and speed. Using statistical ranging to compute uncertainties on multi-opposition orbits would be crazy, not unlike using a sledge hammer to drive a brad. Elegance requires that you use the most simple method that is suitable, but, frankly, method 3) will work reasonably well for virtually all cases. And, yes, Bill, it's really that simple!

6) Did I say five? Well, there is also the semi-linear method. But you definitely don't want to go there. It's more complicated than multiple solutions! I'm just adding this to keep out of trouble with Andrea Milani. ;-)

-Steve Chesley
--
Navigation & Mission Design Section, MS 301-150
Jet Propulsion Laboratory
Pasadena, California 91109
(818) 354-9615, Fax: 393-6388


E. L. G. Bowell wrote:

Bill:
You are essentially describing a technique that has already been published under the name of statistical ranging. The primary reference is Virtanen et al. (Icarus 154, 412, 2001), and there is additional work in Muinonen et al. (Celest. Mech. and Dyn. Astron. 81, 93, 2001). There is an application to TNOs by Virtanen et al. (Icarus, in press), and a URL on same at http://asteroid.lowell.edu/cgi-bin/virtanen/tnoeph. There will also be a description of statistical ranging and other recent orbit methods in Bowell et al. (in Asteroids III, U. Arizona Press, 2003).
Cheers...Ted


Hi folks,

I'm pondering adding a Monte Carlo routine to my orbit determination
code, for uncertainty determination. If I understand it properly,
this is a very straightforward process:

(1) Add some Gaussian noise to your original observations, in both
RA and dec (and perhaps in time, as well... important for VFMOs.)
The amount of the noise should reflect the assumed uncertainties in
the observations.

(2) Solve for the resulting "fuzzified" orbit.

(3) Repeat until you've got a few zillion almost, but not quite,
identical orbits. This may range from a "go away for a cup of
coffee" to a "let the process run in the background for a few
days" kind of job.

(4) To illustrate the uncertainty area for a given date, just
show your zillion or so simulated objects. They'll appear as a
"cloud", and if you've got enough of them, their density will make
the likely placement of the target object apparent.

Is it really that easy, or am I missing something?

(If it _is_ this easy, I'm gonna be kicking myself for not having
done it a long time ago.)

-- Bill


Re: {MPML} Vermin of the Skies

E. L. G. Bowell
 

According to Cunningham (Introduction to Asteroids, p. 10): "They came to be
called vermin of the skies, probably from a German astronomer who called it
[sic] a "plague of minor planets."" From the location of the sentence in
Cunningham's text, one can suppose that the appellation came from the dawn of
asteroid photography in about 1890.

Cheers...Ted

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I can also attest that the phrase has been independently invented at Tenagra
Observatories
which runs an extensive supernova search. MPs are constantly being flagged by
the search
programs. I believe that we began using the phrase in 1998 at 848. It is
used less often
at 926.

My collaborator at UC Berkeley, Weidong Li (from the Peoples Republic of
China) has
brought it into his colloquial English as "Celestial Rats". Has a certainly
heavenly ring to it.

The above is my comment only and does not reflect the
views of any other Tenagra Observatory personnel (e.g. Paulo Holvorcem). In
fact
I have deliberately stopped using the phrase as to not injure the
sensibilities of my
exalted Brazilian coworker.

Cheers,

Michael
Tenagra

----- Original Message -----
From: "David S. Dixon" <ddixon@cybermesa.com>
To: <mpml@yahoogroups.com>
Sent: Tuesday, January 28, 2003 9:22 AM
Subject: Re: {MPML} Vermin of the Skies


See - Asteroids: A History by Peebles. There is a genesis for the
phrase mentioned in it. As I remember it came about as the result of
translating a comment by an astronomer from German into English.


Greg Crawford wrote:

Maybe someone knows specifically who gets credit for the coinage.
Of course, it is possible that the whole notion that astronomers described
asteroids as "vermin of the skies" is folklore. Without a primary
historical
document it is difficult to prove. Perhaps some "creative" person came up
with
the notion and it has been copied and endlessly duplicated throughout the
literature.

Such a repetition seems to take place in regard to the origin of the idea
that a
planet would be found between Mars and Jupiter. This is constantly
attributed to
the originators of the Titius-Bode Law. For example, Edberg and Levy
(Observing
Comets, Asteroids, Meteors, and the Zodiacal Light. Cambridge.1994) claim
the
search for such a planet had "begun not through a telescope but from the
mind of
Johann Daniel Titius of Wittenburg", in 1766. The same belief is
championed by
numerous articles and books. However, as Fred Price has pointed out (The
Planet
Observers Handbook Cambridge.1994.p.183), more than a century earlier
Johannes
Kepler (1571-1630) had originated this idea and once wrote: "Between Mars
and
Jupiter I put a planet".

At the end of the day we shouldn't give anyone who called minor planets
"vermin
of the skies" credit of any kind! That belongs to the solar system
astronomer
who turned the phrase back on itself, applying it to galaxies. Well, maybe
that's another bit of folklore for which Matt Dawson is responsible. See
here:
http://www.bitnik.com/mp/archive/Astrometrist.html No. 5. ;-)

Greg Crawford
- with more historical curiosities on a cloudy night.

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{MPML} Asteroids III Availability

Brian D. Warner
 

Alain,

I just meant you could upload Ted's article while waiting for amazon
to send you a copy of the book.
<<<<

Understood. Actually, I'm thinking of waiting until the movie comes
out ;=)

French songs in Chile? Yes, I can see why you'd troll the Internet!

Back in 1970, when in Mexico for the total solar eclipse, we met an
astronomer from Switzerland who showed us his German-Spanish/Spanish-
Germal dictionary. Doubly useless to me <g>

Clear Skies,
Brian


Re: {MPML} Monte Carlo uncertainty estimation

Alain Maury <amaury@...>
 

brianw_mpo wrote:

Alain,


Why don't you download it (less than 100 Mo ) or just the section you want while it is available...
<<<<

As I understood, that site was really meant for authors only, and not for people to grab a free version ala stealing songs via Napster <g>.
I will buy the book when it will become available. I have in the past gotten things from Napster and a few others, and have generally bought the CDs of the interesting ones, deleted the others, when I could (for example it is hard to get french songs in Chile, and I could hear a CD and decide to buy it on my next trip). I didn't feel like stealing, but trying.
I just meant you could upload Ted's article while waiting for amazon to send you a copy of the book.
alain

Out of principle, I don't mind paying, despite the $110 price. Besides, I already have hard cover versions of I and II so getting the real thing will compliment the set.
Clear Skies,
Brian Warner


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Re: {MPML} Monte Carlo uncertainty estimation

Brian D. Warner
 

David,

FEB 03
<<<


It now being three days past that deadline - WHERE'S MY BOOK?? <g>



Clear Skies,
Brian Warner
Palmer Divide Observatory (IAU 716)
17995 Bakers Farm Rd.
Colorado Springs, CO 80908
http://www.MinorPlanetObserver.com


Collaborative Asteroid Lightcurve Link (CALL)
http://www.MinorPlanetObserver.com/astlc/default.htm


{MPML} Monte Carlo uncertainty estimation

Brian D. Warner
 

Alain,

Why don't you download it (less than 100 Mo ) or just the section you
want while it is available...
<<<<

As I understood, that site was really meant for authors only, and not
for people to grab a free version ala stealing songs via Napster <g>.

Out of principle, I don't mind paying, despite the $110 price.
Besides, I already have hard cover versions of I and II so getting
the real thing will compliment the set.

Clear Skies,
Brian Warner


Re: {MPML} Monte Carlo uncertainty estimation

dixon_lascruce
 

FEB 03

"brianw_mpo " wrote:


Ted,

There will also be a description of statistical ranging and other
recent orbit methods in Bowell et al. (in Asteroids III, U. Arizona
Press, 2003).
<<<<

A book that is very much MIA! <g>

Amazon took my order in October 2002 saying it would deliver in mid-
December, 2002. Still waiting. Do you (or anyone on line who is an
author) have a more up-to-date delivery time?

Clear Skies,
Brian Warner
Palmer Divide Observatory
Colorado Springs, CO

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Re: {MPML} Monte Carlo uncertainty estimation

Alain Maury <amaury@...>
 

Why don't you download it (less than 100 Mo ) or just the section you want while it is available...

http://www.lpi.usra.edu/books/AsteroidsIII/download.html

Alain

brianw_mpo wrote:

Ted,


There will also be a description of statistical ranging and other recent orbit methods in Bowell et al. (in Asteroids III, U. Arizona Press, 2003).
<<<<

A book that is very much MIA! <g>

Amazon took my order in October 2002 saying it would deliver in mid-
December, 2002. Still waiting. Do you (or anyone on line who is an author) have a more up-to-date delivery time?
Clear Skies,
Brian Warner
Palmer Divide Observatory
Colorado Springs, CO



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{MPML} Monte Carlo uncertainty estimation

Brian D. Warner
 

Ted,

There will also be a description of statistical ranging and other
recent orbit methods in Bowell et al. (in Asteroids III, U. Arizona
Press, 2003).
<<<<

A book that is very much MIA! <g>

Amazon took my order in October 2002 saying it would deliver in mid-
December, 2002. Still waiting. Do you (or anyone on line who is an
author) have a more up-to-date delivery time?

Clear Skies,
Brian Warner
Palmer Divide Observatory
Colorado Springs, CO


Re: {MPML} Monte Carlo uncertainty estimation

E. L. G. Bowell
 

Bill:

You are essentially describing a technique that has already been published under
the name of statistical ranging. The primary reference is Virtanen et al.
(Icarus 154, 412, 2001), and there is additional work in Muinonen et al.
(Celest. Mech. and Dyn. Astron. 81, 93, 2001). There is an application to TNOs
by Virtanen et al. (Icarus, in press), and a URL on same at
http://asteroid.lowell.edu/cgi-bin/virtanen/tnoeph. There will also be a
description of statistical ranging and other recent orbit methods in Bowell et
al. (in Asteroids III, U. Arizona Press, 2003).

Cheers...Ted

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Hi folks,

I'm pondering adding a Monte Carlo routine to my orbit determination
code, for uncertainty determination. If I understand it properly,
this is a very straightforward process:

(1) Add some Gaussian noise to your original observations, in both
RA and dec (and perhaps in time, as well... important for VFMOs.)
The amount of the noise should reflect the assumed uncertainties in
the observations.

(2) Solve for the resulting "fuzzified" orbit.

(3) Repeat until you've got a few zillion almost, but not quite,
identical orbits. This may range from a "go away for a cup of
coffee" to a "let the process run in the background for a few
days" kind of job.

(4) To illustrate the uncertainty area for a given date, just
show your zillion or so simulated objects. They'll appear as a
"cloud", and if you've got enough of them, their density will make
the likely placement of the target object apparent.

Is it really that easy, or am I missing something?

(If it _is_ this easy, I'm gonna be kicking myself for not having
done it a long time ago.)

-- Bill


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MPAPW 2003 Web Site

James Roe <jroe@...>
 

The web site for MPAPW 2003 is at http://real-web-services.com/mpapw.php (note the .php!). It contains the current status of the planning for the meeting but, more than that, it is an interactive site that will accept user inputs on line. If this meeting is to be successful, YOU must contribute something - whether a requested topic that you as an audience member would like to hear about, or a topic you have expertise in that you would like to present.

The web site will grow as we move along, so you will want to check it frequently.

Jim Roe


Re: {MPML} Re: Report of the NASA Workshop

dixon_lascruce
 

Brian Skiff wrote:

big list from Dave Dixon snipped...
Unless I'm missing the point, I don't see what Dave seems to see.
Sorting the list by number of object last-observed, and omitting all but
the top contributors:

20 474 15 0.0313 176 0.3674
37 715 18 0.0376 457 0.9541
12 291 21 0.0438 52 0.1086
23 568 25 0.0522 210 0.4384
18 448 26 0.0543 160 0.3340
35 704 41 0.0856 434 0.9061
28 649 55 0.1148 286 0.5971
14 413 66 0.1378 119 0.2484
33 696 96 0.2004 390 0.8142

696 - Mt Hopkins (pro), observing specifically for follow-up/recovery
413 - Coonabarabran (pro), ditto
649 - first-rate amateur operation
704 - LINEAR
448 - Desert Moon (amateur)
568 - Mauna Kea (pro), Dave Tholen follow-up/recovery
291 - Spacewatch II
715 - Jornada/Las Cruces (amateur)
474 - Mount John NZ (pro)

Looks to me as though things are well in hand between the amateurs and
the pros, the latter not necessarily direct survey participants. I don't
see that there's very much to made from it.
Brian that was the point, things are well in hand now not because the surveys
by themselves are able to do adequate follow up but because other system focused
on follow up complete the task for them. Extending this to the future with the
projected super systems makes it reasonable to question the claim of self
follow up capability. And I don't see amateur scope equipment filling the gap
for the proposed systems if discovery is running at 22 to 23 Mag it looks a bit
optimistic even for the professional 1 m to 2.2 m systems.

The last time I saw Alan Harris's analysis of how is the SG survey proceeding
LINEAR was operating at a discovery level of around 19.0V if I remember correctly.
From watching the Date of Last Obs. list follow up seem to taper to an end as
the arc length gets to around 60 days, U gets to 4 or magnitude gets to between
21 and 22. With a few exceptions where an object remains bright (20V and less)
well beyond 60 days or its a VI or PHA. So its follow up for 60 days of arc or
2 to 3 mag dimmer than effective discovery mag. that makes the situation we have
today. I haven't seen an analysis associated with the proposed future systems
that address how to do this if effective discovery is 22V or better.

David



&#92;Brian

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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Re: {MPML} Re: Report of the NASA Workshop

Gary Hug <frogstar@...>
 

"and omitting all but
the top contributors"

Maybe that is the point, we are hampered by day jobs, weather, lack of sizeable
equipment, and usually not the best of sites but we all contribute our small
amount and there is a lot of us. Maybe together with 'the pros' we can all get
the job done.
(brought to you by a contributor of one single "last OBS"..)

Gary Hug
#734

----- Original Message -----
From: "Brian Skiff" <brian.skiff@lowell.edu>
To: <mpml@yahoogroups.com>
Sent: Wednesday, February 05, 2003 11:38 PM
Subject: {MPML} Re: Report of the NASA Workshop


big list from Dave Dixon snipped...
Unless I'm missing the point, I don't see what Dave seems to see.
Sorting the list by number of object last-observed, and omitting all but
the top contributors:

20 474 15 0.0313 176 0.3674
37 715 18 0.0376 457 0.9541
12 291 21 0.0438 52 0.1086
23 568 25 0.0522 210 0.4384
18 448 26 0.0543 160 0.3340
35 704 41 0.0856 434 0.9061
28 649 55 0.1148 286 0.5971
14 413 66 0.1378 119 0.2484
33 696 96 0.2004 390 0.8142

696 - Mt Hopkins (pro), observing specifically for follow-up/recovery
413 - Coonabarabran (pro), ditto
649 - first-rate amateur operation
704 - LINEAR
448 - Desert Moon (amateur)
568 - Mauna Kea (pro), Dave Tholen follow-up/recovery
291 - Spacewatch II
715 - Jornada/Las Cruces (amateur)
474 - Mount John NZ (pro)

Looks to me as though things are well in hand between the amateurs and
the pros, the latter not necessarily direct survey participants. I don't
see that there's very much to made from it.

&#92;Brian

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MPML is supported in part via the 2002 Shoemaker NEO Grant Program of The
Planetary Society (http://www.planetary.org)

NOTICE: Material quoted or re-posted from the Minor Planet Mailing List should
be proceeded
by the following attribution:

FROM THE MINOR PLANET MAILING LIST [date]. For the full text or to subscribe,
please visit:
MPML Home page: http://www.bitnik.com/mp
MPML FAQ: http://www.bitnik.com/mp/MPML-FAQ.html
MPML's Yahoogroups page: http://www.yahoogroups.com/group/mpml

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