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Posted by: volcanopele Sep 25 2008, 11:48 PM

Anyone have a details from the IAU Circular #8980? The subject headers suggest that two satellites have been discovered at 216 Kleopatra, an oddly shaped M-type main belt asteroid.

Posted by: tasp Sep 26 2008, 03:07 AM

Introduction to Asteroids mentions a possible satellite detection via occultation in 1980. Curious if the orbits of either moon(let) are consistent with that event.

Posted by: Holder of the Two Leashes Sep 27 2008, 04:58 AM

Did my best, but all I can come up with is the circular itself, which is password protected (you knew that already).

Searching through the MPECs from the MPC, and information on AstDys, didn't turn up anything obvious.

Kleopatra is just a couple weeks past opposition, so whatever observations may be involved could have been very recent.

Back in 1999, there was a lot of discussion of Kleopatra actually being two separate objects in orbit around each other, a binary asteroid. Arecibo observations seemed to indicate, by radar, that it was a single dogbone shaped object, but I'm wondering if maybe this S1 and S2 business might be taking it back the other direction. Just speculating.

Mainly, I'm wondering how you get two smaller satellites into stable orbits around a "dogbone" unless they're really far out.

Posted by: David Sep 27 2008, 05:35 PM

They ought to name one of the moons "Caesarion". And the other one, I suppose, "Marcus Antonius".

Posted by: Phil Stooke Sep 28 2008, 01:28 AM

There was a stellar occultation by Kleopatra on Sept. 26, visible from Australia. No word on results yet.

Phil

Posted by: Holder of the Two Leashes Sep 28 2008, 02:15 AM

Careful. If they ever name an asteroid "Augustus" (Augusta and Augustinus are as close as they've come so far), then said asteroid might feel an obligation to collide with one or both moons.

Speaking of occultations, I had forgotten that the 1991 event was well enough observed to demonstate that Kleopatra is all but proven to be a single body, so I suppose we really are talking about moons here.

Posted by: peter59 Oct 2 2008, 04:58 PM

Composite image of (216) Kleopatra observed with the 10m-Keck II telescope and its adaptive optics system on September 19 2008 UT. The arrows indicate the position of the newly discovered satellites with temporary names S/2008 (216) 1 and S/2008 (216) 2.

http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=081002-seti-dogbone-02.jpg&cap=Composite+image+of+%28216%29+Kleopatra+observed+with+the+10m-Keck+II+telescope+and+its+adaptive+optics+system+on+September+19+2008+UT.+The+central+dark+circle+shows+the+dog-bone+shape+of+the+primary.+The+arrows+indicate+the+position+of+the+newly+discovered+satellites+with+temporary+names+S%2F2008+%28216%29+1+and+S%2F2008+%28216%29+2.+Credit%3A+F.+Marchis%2C+et+al%2C+SETI+Institute%2C+UC+Berkeley