[meteorite-list] Meteorwrong ;-) falls in Brazil

From: MexicoDoug <MexicoDoug_at_meteoritecentral.com>
Date: Wed Aug 30 16:55:36 2006
Message-ID: <000001c6cc76$94f79aa0$66068cc9_at_0019110394>

Hi Cometfinder Rob !

While you work that (space) junk out ...

C/2006 M4 (SWAN)
Discovered by Rob Matson and Michael Mattiazzo
June 20, 2006

Congratulations this time you got the big one !!

In another month we can all probably see M4 in the binoculars ... and if it
doesn't get too diffuse maybe as brightly or even brighter than any of the
asteroids !

Way to go.

ref: http://ares.nrl.navy.mil/sungrazer/index.php?p=news_arch2006

"As with SWAN's previous discovery, Rob Matson has been kind enough to share
his discovery story, plus some images from Rob McNaught and Sebastian
Hoenig."

"I first spotted the comet around 10:30 am exactly a week ago today when the
7/5 SWAN image was first posted. I should have spotted the comet a few days
earlier, but as I later explained to Brian Marsden and Tim Spahr at MPC, I
missed it because it was hugging one of the superimposed gridlines. By the
time of the 7/5 image, though, the comet had enough separation from the grid
line to draw attention to itself.

I e-mailed Eric Christensen at Catalina Sky Survey (with whom I'd been
working on a different SWAN candidate) that our old phantom had disappeared,
but had been replaced by something much more promising, and I would get back
to him once I confirmed it wasn't a known comet.

By 11 am I had checked known bright comets and found no matches, but wrote
Eric back that due to the sky location, the southern hemisphere was the only
hope for confirmation. I measured pixel positions for six nights from 6/20
to 7/5, converted to ecliptic coordinates and then to equatorial. I checked
residuals on a parabolic orbital solution, tweaked a few positions until I
was satisfied, and at 1:22 pm sent a discovery report and rough ephemeris to
Brian and Tim Spahr at MPC. Ten minutes later I sent the same positions to
Eric.

Since the southern hemisphere was the only hope for confirmation, the next
step was to contact Rob McNaught and Gordon Garradd at Siding Spring
Observatory to see what they could do. Like most observatories, SSO was down
for full moon and wasn't planning their next run until Thursday. But just in
case, I sent Rob and Gordon predicted comet positions for Monday and
Tuesday, and told them if no additional SWAN images appeared by Wednesday,
I'd extend the ephemeris a few more days.

That evening I was able to check my e-mail and confirm that Tim had gotten
my message; also, Rob replied that he would try for the comet on Thursday
from the Uppsala telescope. There were no new SWAN images Tuesday so I went
ahead and extended the ephemeris through Friday for Rob, running some
excursions to give him an idea of positional uncertainty. A few hours later,
Rob replied that Michael Matiazzo had independently found the same comet and
reported it to him. He also indicated that he was thinking about heading up
to SSO a day early if the weather cooperated.

Well, late Tuesday night (Wednesday afternoon for Australia) Rob informed me
that Terry Lovejoy had located the comet in one of his June 30th survey
images from Thornlands, QLD, and forwarded me Terry's crop of an image stack
showing a noticeably green cometary object. The weather had cleared
sufficiently for Rob to make the decision to head up to Siding Spring, so I
checked Terry's position against my rough orbit to see if it needed some
real-time tweaking before Rob made the recovery attempt. I didn't have all
of my astronomy tools on my laptop, but working from my hotel room I decided
that my predicted position needed to shift a bit to the east and to the
north. I forwarded the correction to Rob and at 1 am cross my fingers and
called it a night.

Wednesday morning I got the blow-by-blow in a series of messages from Rob.
The comet wasn't at the nominal position (no surprise), but it was off by
quite a bit more than I would have expected -- nearly 3 degrees. Indeed --
it is a testament to Rob's skill and perseverance that he was able to spiral
out and locate it before the comet set at his location."




----- Original Message -----
From: "Matson, Robert" <ROBERT.D.MATSON_at_saic.com>
To: <meteorite-list_at_meteoritecentral.com>
Sent: Wednesday, August 30, 2006 3:13 PM
Subject: [meteorite-list] Meteorwrong ;-) falls in Brazil


> Hi All,
>
> Not quite a new meteorite fall, but the manmade equivalent:
>
> http://noticias.terra.com.br/brasil/interna/0,,OI1113465-EI306,00.html
>
> Will work on trying to identify the likely satellite that decayed...
>
> --Rob
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
Received on Wed 30 Aug 2006 04:39:10 PM PDT