Hello all,
From experience, I would say that Chile and ASAP are two things which don't
mix, unless it really is ASAPAYARNIAH meaning as soon as possible and you
are really not in a hurry.
But yes, the sky might be slightly better than in Ireland. In fact, who does
astronomy in Ireland... :) You've got to be kidding... Tssss
Good joke :)
Alain
-----Message d'origine-----
De : mpml@yahoogroups.com [mailto:mpml@yahoogroups.com] De la part de Dave
McDonald
Envoyé : mardi 9 février 2010 19:11
À : marcel_klein@...; mpml@yahoogroups.com
Objet : RE: {MPML} NEOCP Follow up requested
Which Christmas?
Seems like we've had bad weather since Christmas 2008 here in Ireland :-(
Some would argue that its been an even longer spell...
Dave (looking to move to Chile ASAP)
-----Original Message-----
From: mpml@yahoogroups.com [mailto:mpml@yahoogroups.com] On Behalf Of
marcel_klein@...
Sent: 09 February 2010 20:54
To: mpml@yahoogroups.com
Subject: Re: {MPML} NEOCP Follow up requested
Hello Richard,
sorry, in Germany the weather is very bad, too. In our region there was not
one night with good sky conditions since christmas :-(
Regards
Marcel Klein
-----Original Message-----
Date: Tue, 09 Feb 2010 21:33:00 +0100
Subject: {MPML} NEOCP Follow up requested
From: Richard Kowalski <kowalski@...>
To: MPML <mpml@yahoogroups.com>
As has been the pattern this year, we had another clear night
following yet another snow storm over the Santa Catalina Mountains, and a
number of new objects have hit the NEOCP.
However, also continuing the pattern, the skies have turned gray as the
next storm approaches from the west. It's anticipated we'll be down for a
few more nights as the snow falls yet again. (We currently have about 1.5
meters of snow on the ground at G96)
It is unlikely that any of the normal follow up stations in the US
Southwest will be able to do any follow up of the 17 objects on the NEOCP
for several days. Any additional effort to follow up the objects on the
page will be, as always, greatly appreciated.
Thanks
--
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
http://www.lpl.arizona.edu/css/
------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Posts to this list or information found within may be freely used, with the
stipulation that MPML and the originating author are cited as the source of
the information.Yahoo! Groups Links
------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Posts to this list or information found within may be freely used, with the
stipulation that MPML and the originating author are cited as the source of
the information.Yahoo! Groups Links
__________ Information provenant d'ESET NOD32 Antivirus, version de la base
des signatures de virus 4852 (20100209) __________
Le message a iti virifii par ESET NOD32 Antivirus.
http://www.eset.com
Which Christmas?
Seems like we've had bad weather since Christmas 2008 here in Ireland :-(
Some would argue that its been an even longer spell...
Dave (looking to move to Chile ASAP)
-----Original Message-----
From: mpml@yahoogroups.com [mailto:mpml@yahoogroups.com] On Behalf Of
marcel_klein@...
Sent: 09 February 2010 20:54
To: mpml@yahoogroups.com
Subject: Re: {MPML} NEOCP Follow up requested
Hello Richard,
sorry, in Germany the weather is very bad, too. In our region there was
not one night with good sky conditions since christmas :-(
Regards
Marcel Klein
-----Original Message-----
Date: Tue, 09 Feb 2010 21:33:00 +0100
Subject: {MPML} NEOCP Follow up requested
From: Richard Kowalski <kowalski@...>
To: MPML <mpml@yahoogroups.com>
As has been the pattern this year, we had another clear night
following yet
another snow storm over the Santa Catalina Mountains, and a number of
new
objects have hit the NEOCP.
However, also continuing the pattern, the skies have turned gray as the
next
storm approaches from the west. It's anticipated we'll be down for a
few more
nights as the snow falls yet again. (We currently have about 1.5 meters
of snow
on the ground at G96)
It is unlikely that any of the normal follow up stations in the US
Southwest
will be able to do any follow up of the 17 objects on the NEOCP for
several
days. Any additional effort to follow up the objects on the page will
be, as
always, greatly appreciated.
Thanks
--
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
http://www.lpl.arizona.edu/css/
------------------------------------
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Posts to this list or information found within may be freely used, with the
stipulation that MPML and the originating author are cited as the source of
the information.Yahoo! Groups Links
Hello Richard,
sorry, in Germany the weather is very bad, too. In our region there was
not one night with good sky conditions since christmas :-(
Regards
Marcel Klein
-----Original Message-----
Date: Tue, 09 Feb 2010 21:33:00 +0100
Subject: {MPML} NEOCP Follow up requested
From: Richard Kowalski <kowalski@...>
To: MPML <mpml@yahoogroups.com>
As has been the pattern this year, we had another clear night
following yet
another snow storm over the Santa Catalina Mountains, and a number of
new
objects have hit the NEOCP.
However, also continuing the pattern, the skies have turned gray as the
next
storm approaches from the west. It's anticipated we'll be down for a
few more
nights as the snow falls yet again. (We currently have about 1.5 meters
of snow
on the ground at G96)
It is unlikely that any of the normal follow up stations in the US
Southwest
will be able to do any follow up of the 17 objects on the NEOCP for
several
days. Any additional effort to follow up the objects on the page will
be, as
always, greatly appreciated.
Thanks
--
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
http://www.lpl.arizona.edu/css/
The new P/2010 C1 (Scotti) is yet another comet with an interesting evolution in
its orbit. With precovery observations back to 2008, this object now has a
orbit extending over 13 months, and its motion can be predicted with fair
confidence.
According to the orbit in MPEC 2010-C26, a=7.06 AU, e=0.26, and i=9 degrees. On
Nov. 7, 2085, there will be a close approach to Jupiter of 0.27 AU. After
another encounter in 2092, a=5.33 AU, e=0.10, and i=14 degrees.
But the most interesting encounter was a very close approach to Saturn on Mar.
26, 1877, when the nominal distance was only 0.014 AU. The orbit prior to this
close approach must be very uncertain, but the formal solution gives the period
as 50 years pre-encounter compared to 20 years post-encounter.
Andrew
http://members.shaw.ca/andrewlowe/home.htm
As has been the pattern this year, we had another clear night following yet
another snow storm over the Santa Catalina Mountains, and a number of new
objects have hit the NEOCP.
However, also continuing the pattern, the skies have turned gray as the next
storm approaches from the west. It's anticipated we'll be down for a few more
nights as the snow falls yet again. (We currently have about 1.5 meters of snow
on the ground at G96)
It is unlikely that any of the normal follow up stations in the US Southwest
will be able to do any follow up of the 17 objects on the NEOCP for several
days. Any additional effort to follow up the objects on the page will be, as
always, greatly appreciated.
Thanks
--
Richard Kowalski
Catalina Sky Survey
Lunar and Planetary Laboratory
University of Arizona
http://www.lpl.arizona.edu/css/
>> Just a comment. A number of folk were unsuccessful in trying to find
>> this
>> object after it was discovered by WISE on Jan 22-24 and subsequently
>> posted
>> on the NEOCP. For example, on February 3 the object was some 34
>> arcminutes
>> distant (dRA=29', dDec=17') from the nominal target position, making it
>> rather difficult to find for those people working with small FOVs. At
>> the
>> time, the estimated positional uncertainty was more like 4 arcminutes.
>
Dave Tholen asked:
> Estimated by whom? The real positional uncertainty was much larger.
Dave - the comment relates to the extent of the uncertainty map displayed
via the NEOCP. The scatter cloud of positions at the time were largely
orientated N-S with little E-W dispersion so I conducted a short N-S search
to no avail. Surprisingly, the true offset was significantly greater in RA.
Gareth has already remarked on some of the limitations re. predictions based
on the early WISE observations.
Richard
--- In mpml@yahoogroups.com, Robert McNaught <rmn@...> wrote:
>
> Additional to Richard's comment: as of yesterday, there were still
> only 3 WISE positions on the NEOCP but the MPEC has 13, and those
> with good residuals. Had these been available at the time Richard
> looked, the ephemeris uncertainty should have been quite small.
In a message mistakenly sent only to Rob, I pointed out that
the observations on the NECOP were a selection from the original
submission, which came from an early version of the processing pipeline. What
appeared on the MPEC is from a newer version of
the pipeline, which is substantially better. Rob responded,
apparently only to me, that he was making the point that taking
so long to get decent positions would alienate follow-up
observers. I agree that that is a risk, but with the improved
pipeline in place, this should be much less of a problem.
I will note that these early WISE observations are also a
learning process for us at the MPC. A number of core programs
required minor alterations to work fully with the WISE
observations.
Please note that I'm not making any official statement on behalf
of WISE. I'm sure Amy Mainzer will be more than happy to give an
official viewpoint.
Gareth
> Just a comment. A number of folk were unsuccessful in trying to find this
> object after it was discovered by WISE on Jan 22-24 and subsequently posted
> on the NEOCP. For example, on February 3 the object was some 34 arcminutes
> distant (dRA=29', dDec=17') from the nominal target position, making it
> rather difficult to find for those people working with small FOVs. At the
> time, the estimated positional uncertainty was more like 4 arcminutes.
Estimated by whom? The real positional uncertainty was much larger.
Additional to Richard's comment: as of yesterday, there were still
only 3 WISE positions on the NEOCP but the MPEC has 13, and those
with good residuals. Had these been available at the time Richard
looked, the ephemeris uncertainty should have been quite small.
It would also be useful to other follow up observers to have comments
of failure to find an object posted on the NEOCP. At E12, we will
be trying for a number of WISE NEOCP objects and while we have the
field of view (2 degrees), we have only 0.5-m aperture. It may often
be the case that we will have to spend tens of minutes observing a
single object to be have a reasonable chance of going faint enough.
To be a cooperative process there should be as much information as
possible available to prospective observers.
Cheers, Rob
Thanks Ernesto,
Just a comment. A number of folk were unsuccessful in trying to find this
object after it was discovered by WISE on Jan 22-24 and subsequently posted
on the NEOCP. For example, on February 3 the object was some 34 arcminutes
distant (dRA=29', dDec=17') from the nominal target position, making it
rather difficult to find for those people working with small FOVs. At the
time, the estimated positional uncertainty was more like 4 arcminutes.
This may have been an unusually wayward WISE NEO - we shall see.
Richard Miles
----- Original Message -----
From: "walcom77" <walcom77@...>
To: "mpml (list) mpml" <mpml@yahoogroups.com>
Sent: Monday, February 08, 2010 8:17 PM
Subject: {MPML} COMET P/2010 B2 (WISE)
> First comet discovered by WISE (NASA's Wide-field Infrared Survey
> Explorer) :
>
> COMET P/2010 B2 (WISE)
>
> http://www.cfa.harvard.edu/mpec/K10/K10C23.html
>
> Ciao,
> Ernesto Guido
Dispite rumors to the contrary, there are actually some of us in the US
who did not watch the Superbowl, but we did see England play Wales
yesterday.
Thanks for sending the link! :)
Larry
> For those outside the U.S. who didn't get to see a particular beer
> commercial
> during the Super Bowl the astronomy world is twittering about: Right now
> it's
> at http://www.youtube.com/watch?v=23nysgG7_Rc (but may well disappear for
> copyright reasons). And with that message back to regular programming ...
>
> Dan 'just the messenger' Fischer
>
For those outside the U.S. who didn't get to see a particular beer commercial
during the Super Bowl the astronomy world is twittering about: Right now it's
at http://www.youtube.com/watch?v=23nysgG7_Rc (but may well disappear for
copyright reasons). And with that message back to regular programming ...
Dan 'just the messenger' Fischer
http://dawn.jpl.nasa.gov/mission/journal_1_30_10.asp
Dawn Journal
Dr. Marc Rayman
January 30, 2010
Dear Plausible Dawniabilities,
Patiently and reliably continuing with its interplanetary voyage,
Dawn is now flying in a new configuration and, from the
perspective of those readers who may be on Earth, in a new direction.
The spacecraft still spends most of its time gradually changing
its orbit around the Sun by thrusting with its ion propulsion
system. The probe is outfitted with 3 ion thrusters, assigned the
heartwarming names thruster #1, thruster #2, and thruster #3. (The
nomenclature and locations of the units were divulged in a log
shortly after launch, before
such information could be distorted and used unethically by
others.) The ship only uses 1 thruster at a time. All 3 were
tested during the 80-day initial checkout phase of the mission,
and when the interplanetary cruise phase commenced in December
2007, it was thruster #3 that was
responsible for pushing the spacecraft away from the Sun. It
performed flawlessly, but engineers plan to share the workload
among the thrusters over the course of the 8-year mission, so
thruster #1 was called into action in June 2008.
By that time, stalwart #3 had been operated
in space for 158 days. (For those readers who have just returned
from an enjoyable excursion back to that log, the apparent
discrepancy between the 158 days of operating time given here and
the 149 days presented there is not an error. The smaller value is
the operating time in the interplanetary cruise phase. Thruster #3
had accumulated about 9 days of operation during the initial
checkout phase.)
Thruster #1 was in service until this month. Although it remains
in excellent condition, engineers transmitted instructions in
December for the spacecraft to reconfigure for use of a different
thruster after its weekly communications session on January 4. By
that time, #1 had thrust for almost 318 days. With its famously
efficient use of xenon propellant, all that maneuvering consumed
only 84.6 kg (187 pounds), yet it imparted 2.2 kilometers/second
(4900 miles/hour) to the spacecraft.
Now it is #2?s turn. It had barely more than 1 day of total
running time in space prior to this month, having been used only
for some tests in November 2007 and April and May 2009. Now 2010 will
be its year to shine (with a lovely blue-green glow). In addition,
as we will see in the next log, for the entirety of the mission,
thruster #2 will have the distinction of providing the greatest
acceleration to the spacecraft of any of the thrusters.
There is much more to the ion propulsion system than the
thrusters. As explained in more detail in an earlier log,
the system also includes 2
computer controllers and 2 units that draw as much as 2500 watts
from Dawn's solar arrays and converts the power to the currents
and voltages the thrusters need. Controller #1 and power unit #1
are used for both thruster #1 and #3, so those electrical devices
have already worked extensively during the mission, although most
of their operation still lies ahead. For now, though, controller
#2 and power unit #2 are in charge.
Although thruster #2 and its associated components have spent most
of their time in space unpowered, they all are now performing just
as smoothly as the other ion propulsion system elements did when
they were in use.
Most of the artistic depictions of the spacecraft in flight happen
to show it using thruster #2, the one nearest the main antenna. So
the next time you see such an image, probably even at the top of
this very page, you might consider that it is very much the way
the spacecraft would look right now if you could see it.
Of course, Dawn is much too far from Earth to be seen by human
eyes, even aided by the most powerful telescopes. But it has
recently come nearer to the planet than it had been for nearly 2
years. As we have discussed in many logs (see, for example,
November 2008), Earth and Dawn move
independently through the solar system. Just as the hands of a
clock sometimes move closer together and sometimes farther apart,
Dawn and Earth sometimes approach each other and sometimes separate.
Some readers may not be at all surprised that even as the probe is
receding from the Sun well over 2 years after launch, blazing a
trail through the asteroid belt, constantly changing its own orbit
(unlike most spacecraft, which coast most of the time, just as
planets do), it is no farther from Earth than it was just 5 months
after launch. They are excused from reading the material below.
Others, however, may find this discussion helpful in thinking more
about why this occurs. It is not important for the mission, but it
may be satisfying for those who wish to direct a metaphorical gaze
to the distant craft.
Unlike clock hands, Dawn does not travel in a circular path.
Following the initial push away from Earth by the Delta rocket
that carried it from Cape Canaveral into space, its orbit around
the Sun was elliptical (see the second row of the table here.
Its path has changed a great deal
since then, principally because of the extensive thrusting (but
also because of the gravitational boost from Mars).
Although elliptical orbits distort the picture a little, the
essentials of the clock analogy are valid, so let's imagine this
alignment by considering the same clock we have used twice before,
most recently last month. (For
readers who now have more clocks than room to display them, we
promise that this will be that last reference to a clock from the
Dawn gift shop, at least until your clocks' warranties have
expired.) With the Sun at the center, Earth is at the tip of the
shorter hand and Dawn at the tip of the longer one. On January 25,
the star, planet, and spacecraft were aligned as closely as the
hands of the clock would be at 6:32:16.
When positioned that way, the Sun and Dawn were nearly in opposite
directions from Earth's vantage point. Suppose you were on Earth
on that date and wanted to look in the direction of the
spacecraft. You would have put the Sun at your back and Dawn would
have been less than 6 degrees from your line of sight, equivalent
to being in the center of a (different) clock, having the 12 at
your back, and instead of looking at the 6, shifting your gaze
almost to the next tic mark. (The positions constantly change, and
by the middle of February, you would need to readjust your gaze to
the 7, still keeping the Sun at the 12.)
Although the alignment is the result of the motion of both Earth
and the spacecraft, from the terrestrial perspective, with our
deceptive sense of cosmic immobility, it seemed that Dawn had been
moving closer to us. Now it seems to be moving away.
Dawn reached its greatest distance from Earth so far in the
mission on November 10, 2008. [Note:
We had decided that it was unnecessary to include a link to that
paragraph, thanks to our encouragement therein for readers to
memorize it. According to our new consultants, Prescient Telepaths
"R Us, you are the sole reader who did not commit it to memory.
Therefore, in our goal to make every customer happy, we are
pleased to include the link specifically for you. Enjoy!] At that
time, it was 2.57 astronomical units (AU) from Earth. Since then,
while its orbit has carried it closer to the Sun and then farther
again, the distance to Earth has been
declining the entire time. The spacecraft and its planet of origin
finally moved to their closest point on January 18, when their
travels brought them to 0.80 AU from each other. (It occurred at
about 2:00 am PST, so if you sleep deeply, you may have missed
it.) The minimum distance did not occur at exactly the same time
as the nearly linear arrangement because the orbits are not as
simple as the circular motion of the clock hands.
The last time they were this close was on March 11, 2008. They
will never be so near each other again. Earth follows the same
orbit around the Sun year after year, but with Dawn constantly
changing its trajectory, pushing deeper into the solar system, the
next time it and Earth are aligned on the same side of the Sun (in
August 2011), the explorer will be much farther away. Indeed, if
all goes according to plan, it will be in orbit around Vesta by
then, beginning to reap the rewards for its long expedition
through the cold depths of space, as it explores a distant and
alien world that waits silently for its first visitor.
Dawn is 0.82 AU (123 million kilometers or 76 million miles) from
Earth, or 345 times as far as the moon and 0.83 times as far as
the Sun. Radio signals, traveling at the universal limit of the
speed of light, take 14 minutes to make the round trip.
This looks like a satelite/rocket/space junk decay.Three decays for Feb.3,2010.
COSMOS 2251 DEB,FENGYUN 1C DEB,DELTA 4 DEB.An event of more than 50 seconds
points to decay event.
Thomas Dorman
--- On Fri, 2/5/10, Dimitry Chestnov <chestd@...> wrote:
From: Dimitry Chestnov <chestd@...>
Subject: {MPML} Huge fireball reported over Ireland
To: mpml@yahoogroups.com
Date: Friday, February 5, 2010, 11:37 AM
Â
Huge fireball reported over Ireland
http://www.universe today.com/ 2010/02/03/ huge-fireball- reported-
over-ireland/
[Non-text portions of this message have been removed]
For those following the outburst of USco (see AAVSO), join the club. In
addition to photometry, I have taken DSS7 spectra Jan 31, Feb 1, and
Feb 4. There are lots of features, and they are changing day to day.
At the moment, I cannot put the results onto our website (my wife is the
expert, and she is out of town), but anyone who is interested may
contact me for results and/or data.
John Menke
menkescientific.com
Feb. 4, 2010
J.D. Harrington
Headquarters, Washington
202-358-5241
j.d.harrington@...
Ray Villard
Space Telescope Science Institute, Baltimore
410-338-4514
villard@...
RELEASE: 10-033
PLUTO'S WHITE, DARK-ORANGE AND CHARCOAL-BLACK TERRAIN CAPTURED BY NASA'S HUBBLE
WASHINGTON -- NASA has released the most detailed and dramatic images
ever taken of the distant dwarf planet Pluto. The images from NASA's
Hubble Space Telescope show an icy, mottled, dark molasses-colored
world undergoing seasonal surface color and brightness changes.
Pluto has become significantly redder, while its illuminated northern
hemisphere is getting brighter. These changes are most likely
consequences of surface ice melting on the sunlit pole and then
refreezing on the other pole, as the dwarf planet heads into the next
phase of its 248-year-long seasonal cycle. Analysis shows the
dramatic change in color took place from 2000 to 2002.
The Hubble pictures confirm Pluto is a dynamic world that undergoes
dramatic atmospheric changes not simply a ball of ice and rock. These
dynamic seasonal changes are as much propelled by the planet's
248-year elliptical orbit as by its axial tilt. Pluto is unlike
Earth, where the planet's tilt alone drives seasons. Pluto's seasons
are asymmetric because of its elliptical orbit. Spring transitions to
polar summer quickly in the northern hemisphere, because Pluto is
moving faster along its orbit when it is closer to the sun.
Ground-based observations, taken in 1988 and 2002 show the mass of the
atmosphere doubled during that time. This may be because of warming
and melting nitrogen ice. The new Hubble images are giving
astronomers essential clues about the seasons on Pluto and the fate
of its atmosphere.
When the Hubble pictures taken in 1994 are compared to those of 2002
and 2003, astronomers see evidence that the northern polar region has
gotten brighter, while the southern hemisphere darkened. These
changes hint at very complex processes affecting the visible surface.
The images will help planetary astronomers interpret more than three
decades of Pluto observations from other telescopes.
"The Hubble observations are the key to tying together these other
diverse constraints on Pluto and showing how it all makes sense by
providing a context based on weather and seasonal changes, which
opens other new lines of investigation," says principal investigator
Marc Buie of the Southwest Research Institute in Boulder, Colo.
These Hubble images, taken by the Advanced Camera for Surveys, will
remain the sharpest view of Pluto until NASA's New Horizons probe is
within six months of its flyby during 2015. The Hubble images are
invaluable for picking the planet's most interesting hemisphere for
imaging by the New Horizons probe.
New Horizons will pass by Pluto so quickly that only one hemisphere
will be photographed in detail. Particularly noticeable in the Hubble
images is a bright spot that has been independently noted to be
unusually rich in carbon monoxide frost. It is a prime target for New
Horizons. "Everybody is puzzled by this feature," Buie said. New
Horizons will get an excellent look at the boundary between this
bright feature and a nearby region covered in pitch-black surface
material.
"The Hubble images also will help New Horizons scientists better
calculate the exposure time for each Pluto snapshot which is
important for taking the most detailed pictures possible," Buie said.
With no chance for re-exposures, accurate models for the surface of
Pluto are essential for properly exposed images.
The Hubble images surface variations a few hundred miles across that
are too coarse for understanding surface geology. But in terms of
surface color and brightness, Hubble reveals a complex-looking world
with white, dark-orange and charcoal-black terrain. The overall color
is believed to be a result of ultraviolet radiation from the distant
sun breaking up methane present on Pluto's surface, leaving behind a
dark and red-carbon-rich residue.
The Hubble images are a few pixels wide. Through a technique called
dithering, multiple, slightly offset pictures are combined through
computer-image processing to synthesize a higher-resolution view than
can be seen in a single exposure.
"This has taken four years and 20 computers operating continuously and
simultaneously to accomplish," Buie said. Buie developed the special
algorithms to sharpen the Hubble data. He plans to use Hubble's new
Wide Field Camera 3 to make additional observations prior to the
arrival of New Horizons.
For Hubble information and images, visit:
http://www.nasa.gov/hubble
-end-
CATALOGO DE BIBLIOGRAFIA BASICA SOBRE CRATERES DE IMPACTO EN SUDAMERICA
1926 - 2008 Rogelio D Acevedo & Maximiliano CL Rocca: Rich Murray 2010.02.04
http://rmforall.blogspot.com/2010_02_01_archive.htm
Thursday, February 4, 2010
http://groups.yahoo.com/group/astrodeep/message/40
_____________________________________________________
http://www.cadic.gov.ar/Articulos/CatalogoCrateresImpactoSudamerica.pdf
CATALOGO DE BIBLIOGRAFIA BASICA SOBRE CRATERES
DE IMPACTO EN SUDAMERICA
Rogelio D. Acevedo1 y Maximiliano C.L. Rocca 2
1 Centro Austral de Investigaciones Científicas (CADIC)
Bernardo Houssay no 200 (V9410BFD)
Ushuaia, Tierra del Fuego, Argentina. acevedo@...
2 Mendoza 2779, 16A, (1428DKU)
Ciudad de Buenos Aires, Argentina.
maxrocca2006@...
LISTADO DE REFERENCIAS:
Se detallan a continuacion, en orden cronologico, las publicaciones
mas importantes sobre crateres de impacto en Sudamerica:
1926:
Nágera, J.
Los hoyos del Campo del Cielo y el meteorito.
Dirección General de Minas, Geología e Hidrología.
Ministerio de Agricultura. Publicación 19.
Este trabajo rechaza el origen de los cráteres de Campo del Cielo
por impacto de meteorito.
1933:
Scheibe, R.
Meteoritas vidriosas de Colombia (tectitas).
Estudios Geológicos Oficiales en Colombia, Tomo I-II, pp.245-255.
Actualmente se considera que no se trataba de tectitas sino de
obsidianas volcánicas.
1965:
Cassidy, W.A.; Villar, L.M.; Bunch, T.E.; Kohman, T.P.; Milton, D.J.
Meteorites and Craters of Campo del Cielo, Argentina.
Science 149: 1055-1064
.
1966:
Ashbee, K.H.G.; Vassamillet, L.F.
Dislocations in a Campo del Cielo meteorite.
Science 151: 1526-1527.
Sánchez, J.; Cassidy, W.A.
A Previously Undescribed Meteorite Crater in Chile.
Journal of Geophysical Research 71 (20): 4891-4895.
Cráter de Monturaqui.
1967:
Cassidy, W.A.
Meteorite Field Studies at Campo del Cielo.
Sky & Telescope 34 (1): 4-10.
1968:
Bunch, T.E.; Cassidy, W.A.
Impact-Induced Deformation in the Campo del Cielo meteorite.
In: Shock Metamorphism of Natural Materials
(B.M. French & N.M. Short editores).
Mono Book Corporation, Baltimore, pp.601-612.
Cassidy, W.A.
Meteorite Impact Structures at Campo del Cielo, Argentina.
In: Shock Metamorphism of Natural Materials
( B.M. French and N.M. Short editores).
Mono Book Corporation, Baltimore, pp.117-128.
Villar, L.M.
La Dispersión meteoritica en Argentina y Chile.
Ciencia e Investigación (Julio): 302-314.
1971:
Cassidy, W.A.
A Small Meteorite Crater: Structural Details.
Journal of Geophysical Research 76 (17): 3896-3912.
Cráter de Campo del Cielo.
Renard, M.L.; Cassidy W.A.
Entry trajectory and orbital calculations for the Crater 9 meteorite,
Campo del Cielo.
Journal of Geophysical Research 76: 7916-7923.
1972:
Bunch, T.E.; Cassidy, W.A.
Petrographic and electron microscope study of the
Monturaqui impactite.
Contributions to Mineralogy and Petrology 36: 95-112.
1973.
Dietz, R.S.; French, B.M.
Two Probable Astroblemes in Brazil.
Nature 244: 561-562.
1978:
McHone, J.; Dietz, R.S.
Astroblemes in Brazil.
Geological Society of America 10: 136-137.
1979:
McHone, J.
Riachao Ring, Brazil: A possible meteorite crater discovered
by the Apollo Astronauts.
Apollo-Soyuz Test. Project NASA Special Publication SP 412,
Report 11: 193-2002.
1981:
Crosta A.P.; Gaspar J.C.; Candia M.A.F.
Feições de Metamorfismo de impacto no domo de Araguainha.
Revista Brasileira de Geociencias 11(3): 139-146.
Theilen-Willige, B.
The Araguainha Impact Structure/Central Brazil.
Revista Brasileira de Geociencias 11(2): 91-97.
1982:
Theilen-Willige, B.
The Araguainha astrobleme, Central Brazil.
Geologischen Rudschau 71: 318-327.
1987:
Corbella, H.
Agrupamientos de cráteres por posible impacto,
Bajada del Diablo, Provincia del Chubut, Argentina.
Revista Asociación Argentina de Mineralogía,
Petrología y Sedimentología 18(1/4): 67.
Crosta, A.P.
Impact Structures in Brazil.
In: Research in Terrestrial Impact Structures (J. Pohl Editor).
Fiedrerich Vieweg & Sohn,
Braunschweig/Wiesbad, pp.30-37.
1988:
Fielding, E.; Alonso, R.N.
Possible impact crater in NW Argentina interpreted from
Thematic Mapper Imagery.
EOS (American Geophysical Union) 69(16): 391.
Cráter de Antofalla.
1989:
Campbell Jr, K.E.; Grieve, R.A.F.; Pacheco-Z, J.; Garvin, J.B.
A newly discovered possible impact structure in Amazonian Bolivia,
National Geographic Research 5 (4): 495-499.
Estructura Iturralde.
1991:
Martínez, I.; Scharer, U.; Deutsch, A.
Determination of shock-wave peak preassure and Rb-Sr isotope
systematics in a granite from the Araguainha impact crater, Brazil.
Lunar and Planetary Science XXII: 857-858.
1992:
Alonso, R.N.,
Possible Impact Crater in NW Argentina Interpreted from
Thematic Mapper Imagery.
III Congreso Geológico de España y VIII Congreso Latinoamericano
de Geología. Actas Tomo 4: 435-439.
Cráter de Antofalla.
Bunch, T.E.; Schultz, P.H.
A study of the Rio Cuarto loess impactites and chondritic impactor
(abstract).
Lunar and Planetary Science XXIII, 179-180.
Deustch, A.; Buhl, D.; Langenhorst, F.
On the significance of crater ages: New Ages for Dellen (Sweden)
and Araguainha (Brazil).
Tectonophysics 216: 205-218.
Engelhardft, E.V.; Mathai, S.K.; Walzebach, J.
Araguainha impact crater, Brazil. I: The Interior part of the uplift.
Meteoritics 27: 442-457.
Grant, J.A.; Schultz, P.H.
Gradation of the Río Cuarto crater field, Argentina (abstract).
Lunar and Planetary Science XXIII, 439-440.
Koeberl, C.; Schultz, P.H.
Chemical composition of meteoritic and impactite samples
from the Río Cuarto Craters, Argentina (abstract).
Lunar and Planetary Science XXIII, 707-708.
Lianza, R. E.
Discovering the crater.
Sky & Telescope, p. 392.
Cráteres de Río Cuarto.
Rampino, M.
A Large Late Permian Impact Structure from the Falkland Plateau.
EOS (AGU) 73: 136.
Rampino, M.
A Major Late Permian event on the Falkland Plateau.
EOS (AGU) 73: 336.
Schultz, P.H.; Beatty, J.K.
Teardrops on the pampas.
Sky & Telescope 83: 387-392.
Río Cuarto, Argentina.
Schultz, P.H.; Grant, J.; Collins, W.; López, J.P.; Toselli,A.J.
Rio Cuarto crater field (abstract).
Lunar and Planetary Science XXIII, 1237-1238.
Schultz, P.H.; Lianza, R.E.
Recent grazing impacts on the Earth recorded in the
Rio Cuarto Crater Field, Argentina.
Nature 355: 234-237.
1993:
Grant, J.A.; Schultz, P.H.
Martian crater degradation by eolian processes:
Analogy with the Rio Cuarto crater field, Argentina (abstract).
Lunar and Planetary Science XXIV, 559-560.
Schultz, P.H.; Koeberl, C.; Bunch,T.
Shock and impactor signatures in Río Cuarto impactites, Argentina
(abstract).
Meteoritics, 28: 432-433.
1994:
Schultz, P.H.; Koeberl, C.; Bunch, T.; Grant, J.; Collins, W.
Ground truth for oblique impact processes:
New insight from the Río Cuarto, Argentina, Crater Field.
Geology 22: 889-892.
1995:
Aldahan, A.A.; Göran Possnert, G.; Koeberl, C.; Schultz,P.
Cosmogenic Be-10 in impact glass and target materials from
the Rio Cuarto craters, Argentina (abstract).
4th International Workshop of the ESF Scientific Network on
"Impact Cratering and Evolution of Planet Earth".
The Role of Impacts on the Evolution of the Atmosphere and
Biosphere with Regard to Short- and Long-Term Changes,
pp. 23-25.
Hammerschmidt, K.; Engelhardt, W.V.
40Ar/39Ar dating of the Araguainha impact structure,
Mato Grosso, Brazil.
Meteoritics 30: 227-233.
1996:
Cassidy, W.A.; Renard, M.L.
Discovering research value in the Campo del Cielo, Argentina,
meteorite craters.
Meteoritics and Planetary Science 31: 433-448.
1997:
Aldahan, A.A.; Koeberl, C.; Göran Possnert, G.; Schultz,P.
10 Be and chemistry of the impactites and target materials from
the Río Cuarto Crater Field, Argentina:
Evidence for surficial cratering and melting.
GFF 119: 67-72.
Masero, W.; Fischer, G.; Shnegg, M.
Electrical Conductivity and Crustal deformation from
Magnetotelluric results in the region of the Araguainha Impact, Brazil.
Physics of the Earth and Planetary Interiors 101: 271-289.
1998:
Hippertt, J.; Lana, C.
Aerial crystallization of hematite in impact bombs from the
Araguainha astrobleme, Mato Grosss, Central Brazil.
Meteoritics and Planetary Science 33: 1303-1309.
2000:
Bercheñi, G.; Pitzu, G.; Alonso R.N.
Cráteres meteoríticos de los Andes Centrales.
XIV Congreso Geológico Boliviano, La Paz, Memorias y CD,
222-226.
2001:
Bland, P.A.; Souza, C.R.,de; Hough, R.M.; Pierazzo, E.; Coniglio, J.;
Pinotti, L.; Jull, A.J.T.; Evers,V.
The Río Cuarto Crater Field re-visited:
Remote Sensing imagery analysis and new field observations.
64th Annual Meteoritical Society Meeting.
2002:
Bland, P.A.; de Souza Filho, C.R.; Jull, A.J.T.; Kelley, S.P.;
Hough, R.M.; Artemieva, N.A.; Pierazzo, E.; Coniglio, J.;
Pinotti, L.; Evers, V.,A.; Kearsley, T.
A Possible Tektite Strewn Field in the Argentinian Pampas.
Science 296: 1109-1111.
Beatty, J. K.
Did Bland rush to conclusions? Controversy brewing over
Río Cuarto craters.
Sky & Telescope, 14 May 2002
http://skyandtelescope.com/news/current/article602_1.asp.
Cione, A.L.; Tonni, E.P.; San Cristóbal, J.; Hernández, P.J.;
Benítez, A.; Bordignon, F.; Perí, J.A.
Putative Meteoritic Craters in Río Cuarto (Central Argentina)
interpreted as eolian structures.
Earth, Moon and Planets 91: 9-24.
Liberman, R.G.; Fernández Niello, J.O.; Di Tada, M.L.; Fifield, L.K.;
Masarik, J.; Reedy, R.C.
Campo del Cielo iron meteorite: sample shielding and meteoroid's
preatmospheric size.
Meteoritics & Planetary Science, 37(2): 295-300.
Melosh, H. J.
Traces of an unusual impact.
Science, 296: 1037-1038.
Cráteres de Río Cuarto.
2003:
Rocca, M.C.L.
Bajo Hondo: A Very Puzzling Crater in Chubut,
Patagonia, Argentina.
Abstract 4001 presentado en la 3rd. Internacional Conference
on Large Meteorite Impacts and Planetary Evolution, Nordlingen,
August 5-7, Alemania.
Rocca, M.C.L.
Potencial Impact Sites in Southern Argentina: Simple Craters?.
Abstract 4002 presentado en la 3 rd. Internacional Conference
on Large Meteorite Impacts and Planetary Evolution, Nordlingen,
August 5-7, Alemania.
Rocca, M.C.L.
Los Mellizos: A Potential Impact Structure in Santa Cruz, Patagonia,
Argentina, South America.
Abstract 4003 presentado en la 3 rd. Internacional Conference
on Large Meteorite Impacts and Planetary Evolution, Nordlingen,
August 5-7, Alemania.
Rocca, M.C.L.
Potential new impact sites in Patagonia, Argentina, South America.
Meteoritics and Planetary Science 38(7): p.A9.
2004:
Crosta, A.P.
A Possible Impact Crater Among Craters:
The Llica Structure in Bolivia.
Meteoritics and Planetary Science 39(8): p.A27.
Crosta, A.P.; Kazzuo-Vieira, C.; Schrank, A.P.
Vista Alegre: A newly impact crater in Southern Brazil.
Meteoritics and Planetary Science 39(8), p.A28.
de Souza Filho, C.R.; Bland, P.A.
Proven, Probably and Possible Impact Craters in South America
Revealed by Aster and SRTM Data and Image Processing
Techniques.
67th Annual Meteoritical Society Meeting.
Rocca, M.C.L.
The crater in Meseta de la Barda Negra, Neuquen, Argentina:
A New meteorite impact site?
Meteoritics and Planetary Science 39(8): p.A89.
Rocca, M.C.L.
Potential Impact Sites in Northern Argentina.
Meteoritics and Planetary Science 39(8): p.A90.
Rocca, M.C.L.
Río Vichada: A possible 50 km wide Impact Structure
in Colombia, South America.
Meteoritics and Planetary Science 39 (8): p.A90.
Romano, R.; Crosta, A.P.
Brazilian Impact Craters: A Review.
Lunar and Planetary Science XXXV.
2005:
Acevedo, R.D.; Rocca, M.C.L.
Revisión Crítica de los posibles cráteres de Impacto
situados en territorio Argentino.
Actas XVI Congreso Geológico Argentino, La Plata, Tomo III:
627-634.
Adepelumi, A.A.; Fklexior, J.M.; Fontes, S.L.
An appraisal of the Serra da Cangalha Impact Structure
using the Euler deconvolution method.
Meteoritics and Planetary Science 40(8): 1149-1157.
Adepelumi, A.A.; Fontes, S.L.; Schnegg, P.A.; Flexor, J.M.
An integrated magnetotelluric and aeromagnetic investigation
of the Serra da Cangalha impact crater, Brazil.
Physics of the Earth and Planetary Interiors 50(1): 159-182.
Crosta, A.P.; Kazzuo-Vieira, C.; Choudhuri, A.; Schrank, A.
Vergeao Dome Astrobleme, SC;
A meteoritic impact record on volcanic rocks of the Parana Basin.
In: Winge, M.; Schobbenhaus, C.; Bert-Born, M.; Queiroz, E.T.;
Campos, D.A. (Editores).
Sitios Geológico y Paleontológicos do Brasil 114.
MacDonald, W.D.; Crosta, A.P.; Francolín, J.
Structural Dome at Sao Miguel do Tapuio, Brazil.
Meteoritics and Planetary Science 41(8):p.A110
Ocampo, A.C.; Garrido, A.C.; Rabassa, J.; Rocca, M.C.L.;
A Possible Impact Crater in Basalt at Meseta de la Barda Negra,
Neuquén, Argentina.
Meteoritics and Planetary Science 40(9): p.A117.
Rocca, M.C.L.
Bajo Hondo, Chubut, Patagonia, Argentina:
A New Meteorite Impact Crater in Basalt?
Meteoritics and Planetary Science 40(9): p.A128.
Serefiddin, F.; Herzog, G.F.; Schultz, P.H.; Schultz, L.
Exposure Histories of Three Meteorites from Río Cuarto, Argentina.
68th Annual Meteoritical Society Meeting (5292.pdf).
2006:
Reimold, W.U.; Cooper, G.R.J.; Romano, R.; Cowan, D.R.;
Koeberl, Ch.
Investigation of Shuttle Radar Topography Mission data of the
possible impact structure at Serra da Cangalha, Brazil.
Meteoritics and Planetary Science 41(2): 237-246.
Rocca, M.C.L.
A Catalogue of Large Meteorite Specimens from Campo del Cielo
Meteorite Shower, Chaco Province, Argentina.
Meteoritics and Planetary Science 41(8): p.A150.
Rocca, M.C.L.
Two New Potential Meteorite Impact Sites in Chubut Province,
Argentina.
Meteoritics and Planetary Science 41 (8): p.A151.
2007:
Acevedo, R.D.; Ponce, F.; Rocca. M; Rabassa, J.; Corbella, H.
Filu-Có plateau: the major impact crater field of Bajada del Diablo
strewnfield, Argentine, Patagonia.
GeoSur. Santiago de Chile. Libro de Resúmenes, 2.
Levine, J.; Arazi, A.; Faestermann, T.; Fenandez Niello, J.O.;
Korschinek, G.; La Gamma, A.M.G. ; Negri, A.; Rugel, G.;
Steier, P.; Wallner, A.
Terrestrial Age Determination of an Achondrite
from Río Cuarto, Argentina.
Lunar and Planetary Science XXXVIII (1362.pdf).
Rocca, M.C.L.
Los Mellizos Structure : A possible new 15 Km wide Impact Crater
in the Deseado Plateau, Santa Cruz Province, Argentina.
Meteoritics and Planetary Science 42(8): p.A131.
Wright, S.P.; Vesconi, M.A.; Spagnuolo, M.G.; Cerutti, C.;
Jacob, R.W.; Cassidy, W.A.
Explosion craters and penetration funnels in the Campo del Cielo,
Argentina, crater field.
Lunar and Planetary Science XXXVIII. 2017 pdf.
2008:
Harris, R.S.; Schultz, P.H.; Tancredi, G.; Ishitsuka, J.
Petrology and ejecta from the Carancas (Perú) Crater:
Insights into the Dynamics of an "unusual" impact event.
In: Asteroids, Comets, Meteors 2008, abstract 8302 pdf.
Schultz, P.H.; Harris, R.S.; Tancredi, G.; Ishitsuka, J.
Implications of the Carancas meteorite impact.
Lunar and Planetary Science XXXIX, abstract 2409 pdf.
Ponce, F.; Acevedo, R.D.; Rocca. M; Rabassa, J.; Corbella, H.
Ubicación geográfica y localización geológica de los cráteres de
impacto de Filu-Có (Bajada del Diablo) Provincia del Chubut,
República Argentina.
Actas del XVII Congreso Geológico Argentino, III:1241-1242.
San Salvador de Jujuy. ISBN 978-987-22403-1-8
_____________________________________________________
third Meteor Night, 7 pm Tuesday Feb 2, SF Complex -- soon I will
show Tim McElvain 3 sites in La Tierra-Las Dos subdivision,
Santa Fe, NM -- my samples show intense blast effects with surface
melting and mineral coatings: Rich Murray 2010.01.28
http://rmforall.blogspot.com/2010_01_01_archive.htm
Thursday, January 28, 2010
http://groups.yahoo.com/group/astrodeep/message/38
large dense fractal meteor cluster in Alaska? also 21 pages re
unusual 0.6 m rock in Palmer: Horace Heffner:
Rich Murray 2010.01.24
http://rmforall.blogspot.com/2010_01_01_archive.htm
Sunday, January 24, 2010
http://groups.yahoo.com/group/astrodeep/message/37
Meteor Night 7 pm tonight, Santa Fe Complex, Santa Fe, Jan 19,
Rich Murray with 10x12 screen on two extensive websites by
Dennis Cox and by Tim McElvain: Rich Murray 2010.01.19
http://rmforall.blogspot.com/2010_01_01_archive.htm
Tuesday, January 19, 2010
http://groups.yahoo.com/group/astrodeep/message/36http://sites.google.com/site/dragonstormproject/
Dennis Cox, Fresno, California
http://www.impactstructure.net/working-hypothesis.html
Thornton H. "Tim" McElvain, Santa Fe, New Mexico
awesome evidence (Google Earth images, stereo pairs, some videos)
from Mexico to Canada for 500 km comet rubble pile air impacts
12950 BP -- Dennis Cox: Rich Murray 2010.01.13
http://rmforall.blogspot.com/2010_01_01_archive.htm
Wednesday, January 13, 2010
http://groups.yahoo.com/group/astrodeep/message/35
exact Carolina Bay crater locations, RB Firestone, A West, et al,
two YD reviews, 2008 June, 2009 Nov,
also 3 upcoming abstracts: Rich Murray 2009.11.14
http://rmforall.blogspot.com/2009_11_01_archive.htm
Saturday, November 14, 2009
http://groups.yahoo.com/group/astrodeep/message/31
Rich Murray, MA
Boston University Graduate School 1967 psychology,
BS MIT 1964, history and physics,
1943 Otowi Road, Santa Fe, New Mexico 87505
505-501-2298 rmforall@...http://groups.yahoo.com/group/AstroDeep/messageshttp://RMForAll.blogspot.com new primary archive
http://groups.yahoo.com/group/aspartameNM/messages
group with 142 members, 1,588 posts in a public archive
http://groups.yahoo.com/group/rmforall/messages
participant, Santa Fe Complex www.sfcomplex.org
_____________________________________________________
I just received the following from a Robert Handley at utahsilver@....
What I do _not_ know about meteor(ites) would fill several books so I can't
answer his questions but hope someone here can.
Any takers?
Many thanks,
patrick
My father has asked me to help him find out about something that he had
experienced in his youth. When he was around 10 years old, give or take a couple
of years, which would have been about 1932. He was out side his home, which was
located at Lofgreen, UT <a couple hour drive SW of Salt Lake City>. He and his
sister were outside and he happened to be looking up at the sky when he saw like
6 or 7 fireballs/meteorites pass thru the sky to the west of him. They passed by
him and headed in northerly direction. Passing out of his sight in a second over
the mountain. He said they were moving very fast, so fast that his sister who
was with him never saw them, before she could look up and look in the direction
of the fireballs. I’ve asked him a bunch of question about his experience and
tried to figure a little bit about it. At first he thought they were quite high
up in the air since they went over the mountains to the north. But he also told
me he could hear them roaring very loudly thru the air and that he felt the heat
of them on his face. He also told me that he felt like a pressure/force ripple
thru his body. This I think my have been something like a shockwave caused by
the fireballs/meteorites as they passed thru the air over him, but that is just
a guess on my part. I also asked him if the trajectory was steep or was it more
flat, and he told me is was fairly flat. He told me the largest of them was like
what he thought to be like 6 feet across down to like 2 feet across on the
smaller ones. These were followed by a mass of small black tiny pieces that were
not burning. He says it happened so fast and so long ago that it is hard to
recall much of the detail about this experience. My thought is if he could hear
and feel the heat and shockwave off them they couldn’t have been to high up in
the sky.
My questions are, I was wondering if you know of any fireballs/meteors that
passed over Utah in or around that time of 1931 to 1933? Also from what I have
read not all of them hit the earth. Also I take they are not called meteorites
unless they do hit the earth. The next question is how high up could they of
been up in the air and still be able to hear and feel the heat off of them?
Another question is with them being that low and with a fairly flat trajectory,
how far do you think they could of traveled before falling to the ground if they
did do that?
Not to bother you too much since I’m not sure if you have such answers for my
dad and me I will end my letter here. I hope you can give me some sort of
insight or information about my question or if not perhaps forward my letter to
some one who might or let me know of such persons and/or groups that might help
me understand and help my understand and know what he saw as a youth.
A team of observers at the BAA are currently doing phase curve studies of 14
target asteroids. One of our targets is (64) Angelina and we have been
following it from phase angles of more than 22 degrees down to the recent
opposition on January 29 when it attained a unique phase angle of 0.00 degrees.
We were successful in securing V-filter images of this object through opposition
thanks to the folks at Tzec Maun (http://www.tzecmaun.org/) who opened up their
Moorook facility in South Australia just hours before full moon for the purpose.
So far, members of the team have observed (64) Angelina on 51 separate occasions
with observations continuing. I imagine that other observers may have also been
studying this object - for instance radar observations have been scheduled from
Arecibo. We invite other observers who may have been carrying out filter
photometry of this object to get in touch with a view to combining their data
with our own.
Richard Miles
Asteroids and Remote Planets Section
British Astronomical Association
arps@...
Hello.
This is the message ATel #2417 of
Josep M. Trigo-Rodriguez (CSIC-IEEC)
on 3 Feb 2010; 17:39 UT
Sincerly.
SOULIER J-F
C10 France
Subjects: Comets
A continuous photometric monitoring of Centaur 29P/Schwassmann-Wachmann 1 is
being currently performed from Spain. We have analyzed multi-band images taken
in V, R, and I filters on Feb. 3.181, 2010 by A. Sanchez (MPC442). This object
exhibits a stellar appearance in the images with an apparent diameter of 15
arcsec. The derived magnitude of the comet in a 10 arcsec standard photometry
field is +11.7 R, +11.5 I, and +11.9 V. These data suggest that this comet is
currently experiencing an unusual outburst, probably the brightest in the last
decade according the recent photometric compilation by Trigo-Rodriguez et al.
(2009) A&A 485, 599. Additional observations obtained in the last month suggest
a progressive increase in activity from mid January from a quite inactive
40-days period in which the comet remained close to +16 R magnitude. Other
significant observations of our follow-up during the last months are listed:
Dec. 20.0400, +16.4 R (J.M. Trigo-Rodriguez, MPC B06); Dec. 25.2482, +16.1 R,
and 15.9 I (A. Sanchez, MPC442); Jan. 09.9700, +15.0 R, +15.7 V, and 15.4 I (S.
Pastor and J.A. Reyes, MPC J76); Jan. 10.0717, +15.6 R (A. Sanchez, MPC442);
Jan. 12.1866, +15.7 R (A. Sanchez, MPC442); Jan. 27.1822, +15.2 R (A. Sanchez,
MPC442); Jan. 27.1822, +15.1 R and 15.2 I (D. Rodríguez, MPC 458). Additional
observations of this object are encouraged to better understand the physical
processes behind the coma evolution after a massive outburst.
The astrometry reported by site 244 is of a different nature to normal CCD
astrometry, and is submitted using a special format (with all positions being
reported via the International Occultation Timing Association)..
The data reported is the time of minimum geocentric separation, that separation,
and the Position Angle, referenced to the occulted star. The observations are
reduced by projecting the location of the observers at each event time onto the
fundamental plane, using a reference frame that is moving with the known motion
of the asteroid. This deals with the varying parallactic shifts as seen by each
of the observers. In this system, the most convenient reporting basis for
astrometry is to provide a position based on the geocentric time of conjunction
and the geocentric separation at that time. The times are reported in units of
10^-7 days (0.01 secs), and the separation in units of 0.1 masec (100
micro-arcsecs) - with formal errors of well-observed events usually being only a
few hundred micro-arcsecs. Indeed, for well-observed occultations of asteroids
smaller than 100km diameter the gross irregularity of the asteroid profile is
the greatest cause of uncertainty in the position we derive - with issues of the
difference between center of figure and center of mass being apparent. See for
example the occultation results for:
135 Hertha http://tinyurl.com/ydk7qsz
234 Barbara http://tinyurl.com/yao4b3s [which shows a heart-shaped profile!]
An example report line is:
747 2009 9 5.4648640 ±0.0000016 0.8807 ± 0.9 113.903 19 29 19.4300
-20 37 30.206 U2 6
where the fields are:
Asteroid number,
year, month day of geocentric conjunction
formal uncertainty (days) of time of conjunction
separation at conjunction (arcsecs)
formal uncertainty in separation (masec)
PA at conjunction
Catalogue RA and Dec of star - J2000, at epoch of observation,
parallax-corrected if from Hipparcos
catalogue source
number of occultation chords used.
The positions as published in the MPO's are 'normal' RA and Dec derived by
combining the 'current' catalogue position of the star with the offset, but
reduced in precision to the usual high precision format used by the MPC for
normal astrometry. Note that unlike usual CCD astrometry, occultation astrometry
can be updated when the catalogue positions of the occulted stars are improved
(for example, following the URAT project, the JMAPS mission, or Gaia.) Note that
at the precision we are working at, the difference between the relativistic
bending of the light coming from the asteroid and the star is potentially
relevant at solar elongations of _greater than 90 degrees_, with the difference
increasing as the geocentric distance to the asteroid is reduced. However at
this time we are not applying any differential relativistic corrections to our
reported astrometry.
Dave Herald
Canberra, Australia
----- Original Message -----
From: Dimitry Chestnov
To: mpml@yahoogroups.com
Sent: Thursday, February 04, 2010 8:23 AM
Subject: {MPML} A question about occultation-derived astrometry
Hi all,
Why it is sufficient to send occultation-derived astrometry under geocentric
code 244 ("Geocentric Occultation Observation")? Why parallax do not interfere
in astrometric precision in this case?
Regards,
Dimitry Chestnov
------------------------------------
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Posts to this list or information found within may be freely used, with the
stipulation that MPML and the originating author are cited as the source of the
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[Non-text portions of this message have been removed]
Hello all,
Well, some people write '2009' on their checks well into 2010.
I just made a similar error, computing ephemerides for January and
February 2009 while thinking about January/February 2010. <Groan>
Peter Birtwhistle e-mailed me privately, wondering why I was
showing the closest approach of this object around 4 February instead
of 6 February. It was, of course, because there were perigees
on 4 Feb 2009 and 6 Feb 2010.
I've corrected the "pseudo-MPEC" accordingly. Good news is,
this makes it a little more likely that somebody may actually find the
object, sometime between 6 and 8 February.
-- Bill
Hi all,
Why it is sufficient to send occultation-derived astrometry under geocentric
code 244 ("Geocentric Occultation Observation")? Why parallax do not interfere
in astrometric precision in this case?
Regards,
Dimitry Chestnov
Hello all,
This bit of space junk is coming around for its monthly perigee.
It would be good if somebody got at least a few observations of
it. It's in an highly elongated orbit, making it only rarely
visible. Also, it's strongly affected by solar radiation pressure
(as is most space junk), making it harder to keep track of
than your average celestial object.
More info is at
http://www.gwi.net/~pluto/mpecs/9u.htm
along with links to the MPC and JPL sites providing ephemerides
for this object.
Unfortunately, I really should have posted this a day or two
ago. The object is still observable, but moving fast and soon
to move around toward low elongations.
Thanks! -- Bill
The minimum distance between two objects: P/2010 A2 and 2010 AA15
in the years 1995-2017 was 0.0155 AU on 2009/11/22.
The result was computed for nominal orbits with all published observations and
using the OrbFit software.
Best regards,
Ireneusz Wlodarczyk
553 Chorzow
--- In mpml@yahoogroups.com, "RICHARD MILES" <rmiles.btee@...> wrote:
>
> Thanks Bill for the analysis. I had received a previous comment offline
> almost 2 weeks ago now about the orbits not intersecting but I was unsure
> about the precision of each orbit at that time.
>
> Like you say these objects have not been involved in any mutual collision in
> the very recent past, so it is quite a coincidence that they were only about
> 0.02 AU apart when the comet was discovered. Of course if one hypothesized
> a collision at some previous intersection point then the coma trailing the
> fragments would have dispersed over the intervening years and so that is not
> a credible scenario either.
>
> I also would have expected material to also have remained close to the
> larger object if it had been involved in a very recent collision but there
> is no indication of any coma in the vicinity of 2010 AA15 from the tracked
> and stacked images.
>
> Presumably, if the collisional hypothesis is the best interpretation of the
> observed phenomenon, it must have involved an object <<100 m in size, of
> which there are many within the MB. Indeed, given a sufficient number
> density of very small objects and the population of small asteroids, it is
> not surprising that we will see this type of phenomenon from time to time.
>
> Richard
>
> ----- Original Message -----
> From: "Bill J Gray" <pluto@...>
> To: "RICHARD MILES" <rmiles.btee@...>
> Cc: <mpml@yahoogroups.com>; <comets-ml@yahoogroups.com>
> Sent: Tuesday, February 02, 2010 7:20 PM
> Subject: Re: {MPML} P/2010 A2, 2010 AA15 results of a collision? (probably
> no)
>
>
> > Hi Richard,
> >
> > Well, you _did_ have me going for a bit here. Unfortunately,
> > I have to tell you that I'm reasonably sure that it's just a
> > coincidence. (And perhaps, given that we're dealing with
> > main-belt objects where the density of objects is high, not
> > as amazing a coincidence as one might think.)
> >
> > Using your new observations for 2010 AA15 plus those from
> > MPCOBS for both objects, I got these orbits and ephemerides:
> >
> > http://home.gwi.net/~pluto/mpecs/2010aa15.htm
> > http://home.gwi.net/~pluto/mpecs/p2010a2.htm
> >
> > The upshot is that they came within 1.5' of one another
> > sometime near 17 January 2010. But before that, they were
> > further apart; this isn't the result of a recent collision,
> > where we can track the objects back to the intersection point.
> >
>
Thanks Bill for the analysis. I had received a previous comment offline
almost 2 weeks ago now about the orbits not intersecting but I was unsure
about the precision of each orbit at that time.
Like you say these objects have not been involved in any mutual collision in
the very recent past, so it is quite a coincidence that they were only about
0.02 AU apart when the comet was discovered. Of course if one hypothesized
a collision at some previous intersection point then the coma trailing the
fragments would have dispersed over the intervening years and so that is not
a credible scenario either.
I also would have expected material to also have remained close to the
larger object if it had been involved in a very recent collision but there
is no indication of any coma in the vicinity of 2010 AA15 from the tracked
and stacked images.
Presumably, if the collisional hypothesis is the best interpretation of the
observed phenomenon, it must have involved an object <<100 m in size, of
which there are many within the MB. Indeed, given a sufficient number
density of very small objects and the population of small asteroids, it is
not surprising that we will see this type of phenomenon from time to time.
Richard
----- Original Message -----
From: "Bill J Gray" <pluto@...>
To: "RICHARD MILES" <rmiles.btee@...>
Cc: <mpml@yahoogroups.com>; <comets-ml@yahoogroups.com>
Sent: Tuesday, February 02, 2010 7:20 PM
Subject: Re: {MPML} P/2010 A2, 2010 AA15 results of a collision? (probably
no)
> Hi Richard,
>
> Well, you _did_ have me going for a bit here. Unfortunately,
> I have to tell you that I'm reasonably sure that it's just a
> coincidence. (And perhaps, given that we're dealing with
> main-belt objects where the density of objects is high, not
> as amazing a coincidence as one might think.)
>
> Using your new observations for 2010 AA15 plus those from
> MPCOBS for both objects, I got these orbits and ephemerides:
>
> http://home.gwi.net/~pluto/mpecs/2010aa15.htm
> http://home.gwi.net/~pluto/mpecs/p2010a2.htm
>
> The upshot is that they came within 1.5' of one another
> sometime near 17 January 2010. But before that, they were
> further apart; this isn't the result of a recent collision,
> where we can track the objects back to the intersection point.
>
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