[meteorite-list] test

From: Pat <bigredwizard_at_meteoritecentral.com>
Date: Wed Aug 10 17:15:55 2005
Message-ID: <000c01c59df0$b4f27e70$0300a8c0_at_tim>

test

----- Original Message -----
From: "Ron Baalke" <baalke_at_zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list_at_meteoritecentral.com>
Sent: Wednesday, August 10, 2005 4:09 PM
Subject: [meteorite-list] VLT NACO Instrument Helps Discover First
TripleAsteroid


>
> http://www.eso.org/outreach/press-rel/pr-2005/pr-21-05.html
>
> ESO Press Release 21/05
> 11 August 2005
>
> Under Embargo until August 10, 2005 at 19:00 CET (17:00 GMT)
> Rubble-Pile Minor Planet Sylvia and Her Twins
>
> VLT NACO Instrument Helps Discover First Triple Asteroid
>
> One of the thousands of minor planets orbiting the Sun has been found to
> have its own mini planetary system. Astronomer Franck Marchis
> (University of California, Berkeley, USA)
> and his colleagues at the Observatoire de Paris
> (France) [1] have discovered the first triple asteroid system -
> two small asteroids orbiting a larger one known since 1866 as 87 Sylvia
> [2].
>
> "Since double asteroids seem to be common, people have been looking for
> multiple asteroid systems for a long time," said Marchis. "I couldn't
> believe we found one."
>
> The discovery was made with Yepun, one of ESO's 8.2-m telescopes of the
> Very Large Telescope Array at Cerro Paranal (Chile), using the
> outstanding image' sharpness provided by the adaptive optics NACO
> instrument. Via the observatory's proven "Service Observing Mode",
> Marchis and his colleagues were able to obtain sky images of many
> asteroids over a six-month period without actually having to travel to
> Chile.
>
> ESO PR Photo 25a/05 <images/phot-25a-05-preview.jpg>
>
> ESO PR Photo 25a/05
>
> Orbits of Twin Moonlets around 87 Sylvia
>
> [Preview - JPEG: 400 x 516 pix - 145k] <images/phot-25a-05-preview.jpg>
> [Normal - JPEG: 800 x 1032 pix - 350k] <images/phot-25a-05-normal.jpg>
>
> ESO PR Photo 25b/05 <images/phot-25b-05-preview.jpg>
>
> ESO PR Photo 25b/05
>
> Artist's impression of the triple asteroid system
>
> [Preview - JPEG: 420 x 400 pix - 98k] <images/phot-25b-05-preview.jpg>
> [Normal - JPEG: 849 x 800 pix - 238k] <images/phot-25b-05-normal.jpg>
> [Full Res - JPEG: 4000 x 3407 pix - 3.7M] <images/phot-25b-05-fullres.jpg>
> [Full Res - TIFF: 4000 x 3000 pix - 36.0M]
> <images/phot-25b-05-fullres.tif>
>
> Caption: ESO PR Photo 25a/05 is a composite image showing the positions
> of Remus and Romulus around 87 Sylvia on 9 different nights as seen on
> NACO images. It clearly reveals the orbits of the two moonlets. The
> inset shows the potato shape of 87 Sylvia. The field of view is 2
> arcsec. North is up and East is left. ESO PR Photo 25b/05 is an artist
> rendering of the triple system: Romulus, Sylvia, and Remus.
>
> ESO Video Clip 03/05 <video/vid-03-05.mov>
>
> ESO Video Clip 03/05
>
> Asteroid Sylvia and Her Twins
>
> [Quicktime Movie - 50 sec - 384 x 288 pix - 12.6M] <video/vid-03-05.mov>
>
> Caption: ESO PR Video Clip 03/05 is an artist rendering of the triple
> asteroid system showing the large asteroid 87 Sylvia spinning at a rapid
> rate and surrounded by two smaller asteroids (Remus and Romulus) in
> orbit around it. This computer animation is also available in broadcast
> quality to the media (please contact Herbert Zodet
> <../../epr/epr-contact.html>).
>
>
> One of these asteroids was 87 Sylvia, which was known to be double since
> 2001, from observations made by Mike Brown and Jean-Luc Margot with the
> Keck telescope. The astronomers used NACO to observe Sylvia on 27
> occasions, over a two-month period. On each of the images, the known
> small companion was seen, allowing Marchis and his colleagues to precisely
> compute its orbit. But on 12 of the images, the astronomers also found a
> closer and
> smaller companion. 87 Sylvia is thus not double but triple!
>
> Because 87 Sylvia was named after Rhea Sylvia, the mythical mother of
> the founders of Rome [3], Marchis proposed naming the twin
> moons after those founders: Romulus and Remus. The International
> Astronomical Union <http://www.iau.org/> approved the names.
>
> Sylvia's moons are considerably smaller, orbiting in nearly circular
> orbits and in the same plane and direction. The closest and newly
> discovered moonlet, orbiting about 710 km from Sylvia, is Remus, a body
> only 7 km across and circling Sylvia every 33 hours. The second,
> Romulus, orbits at about 1360 km in 87.6 hours and measures about 18 km
> across.
>
> The asteroid 87 Sylvia is one of the largest known from the asteroid
> main belt, and is located about 3.5 times further away from the Sun than
> the Earth, between the orbits of Mars and Jupiter. The wealth of details
> provided by the NACO images show that 87 Sylvia is shaped like a lumpy
> potato, measuring 380 x 260 x 230 km (see ESO PR Photo 25a/05). It is
> spinning at a rapid rate, once every 5 hours and 11 minutes.
>
> The observations of the moonlets' orbits allow the astronomers to
> precisely calculate the mass and density of Sylvia. With a density only
> 20% higher than the density of water, it is likely composed of water ice
> and rubble from a primordial asteroid. "It could be up to 60 percent
> empty space," said co-discoverer Daniel Hestroffer (Observatoire de
> Paris, France).
>
> "It is most probably a "rubble-pile" asteroid", Marchis added. These
> asteroids are loose aggregations of rock, presumably the result of a
> collision. Two asteroids smacked into each other and got disrupted. The
> new rubble-pile asteroid formed later by accumulation of large fragments
> while the moonlets are probably debris left over from the collision that
> were captured by the newly formed asteroid and eventually settled into
> orbits around it. "Because of the way they form, we expect to see more
> multiple asteroid systems like this."
>
> Marchis and his colleagues will report their discovery in the August 11
> issue of the journal Nature, simultaneously with an announcement that
> day at the Asteroid Comet Meteor conference in Arma??o dos B?zios, Rio
> de Janeiro state, Brazil.
>
> Notes
>
> [1]: The team is composed of Franck Marchis (University of California,
> Berkeley, USA) and Pascal Descamps, Daniel Hestroffer, and Jerome
> Berthier (Observatoire de Paris, France).
>
> [2]: 87 Sylvia is the 87th minor planet discovered. It was first
> observed from the Observatory of Madras (India) on May 16, 1866, by the
> Government Astronomer Norman R. Pogson. It was common in the early days
> to assign a name - mostly feminine - from the mythology to newly found
> asteroids. Pogson selected a name from the list furnished to him by Sir
> John Herschel.
>
> [3]: In the Appendix <pr-21-05_p2.html>, you can read the story of Syvia
> and her sons, Romulus and Remus.
>
> The press release of the University of California, Berkeley, is
> available here
> <http://www.berkeley.edu/news/media/releases/2005/08/10_sylvia.shtml>
> and the one from the Observatoire de Paris, here
> <http://www.obspm.fr/actual/nouvelle/aug05/sylvia.en.shtml>.
>
> Contacts
>
> Franck Marchis
> University of California, Berkeley, USA
> Phone: +1 (510) 642 3958 or +1 (510) 599 0604
> Email: fmarchis_at_berkeley.edu
>
> Pascal Descamps, Daniel Hestroffer, Jerome Berthier
> IMCCE, Observatoire de Paris, France
> Phone: +33 1 4051 2268 or +33 1 4051 2260
> Email: descamps_at_imcce.fr, hestroffer@imcce.fr, berthier@imcce.fr
>
>
> National contacts for the media:
>
> Belgium - Dr. Rodrigo Alvarez +32-2-474 70 50 rodrigo.alvarez_at_oma.be
> Finland - Ms. Terhi Loukiainen +358 9 7748 8385 terhi.loukiainen_at_aka.fi
> Denmark - Dr. Michael Linden-V?rnle +45-33-18 19 97 mykal_at_tycho.dk
> France - Dr. Daniel Kunth +33-1-44 32 80 85 kunth_at_iap.fr
> Germany - Dr. Jakob Staude +49-6221-528229 staude_at_mpia.de
> Italy - Prof. Massimo Capaccioli +39-081-55 75 511 capaccioli_at_na.astro.it
> The Netherlands - Ms. Marieke Baan +31-20-525 74 80 mbaan_at_science.uva.nl
> Portugal - Prof. Teresa Lago +351-22-089 833 mtlago_at_astro.up.pt
> Sweden - Dr. Jesper Sollerman +46-8-55 37 85 54 jesper_at_astro.su.se
> Switzerland - Dr. Martin Steinacher +41-31-324 23 82
> martin.steinacher_at_sbf.admin.ch
> United Kingdom - Mr. Peter Barratt +44-1793-44 20 25
> Peter.Barratt_at_pparc.ac.uk
>
>
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Received on Wed 10 Aug 2005 05:15:59 PM PDT