Candidate dwarf planet 2003EL61 to eclipse its smallest moon

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h2ouniverse

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<p>Mike Brown's team just realized that EL61 was eclipsing and being transited by its smallest moon these weeks as viewed from Earth. The Earth is in the orbital plane, exceptionnally.</p><p>&nbsp;http://www.mikebrownsplanets.com/2008/05/moon-shadow-monday-fixed.html</p><p>&nbsp;This should not occur again before 130 years.</p><p>It is a series of unexpected opportunities to study the shape of el61 (alledgedly a trixial ellipsoid despite the contradiction with the expectation of hydrostatic relaxation) and its potential atmosphere.</p>
 
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MeteorWayne

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<p>I hate to be repetative, but...</p><div id="post-241771" class="postcolor">Oh, that's great!!<br />It should allow very refined measurements of the parent object, and certainly some for Blitzen.<br /><br />That is fantastic (and darned lucky) news!<br /><br />Considering how much we are learning about this system (Dwarf Planet and satellites, as well of the 5 or more asteroids that came from the original collision), we will learn a a whole bunch.<br /><br />Thanx! </div> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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3488

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I<font color="#ff0000"> hate to be repetative, but...Oh, that's great!!It should allow very refined measurements of the parent object, and certainly some for Blitzen.That is fantastic (and darned lucky) news!Considering how much we are learning about this system (Dwarf Planet and satellites, as well of the 5 or more asteroids that came from the original collision), we will learn a a whole bunch.Thanx! <br />Posted by MeteorWayne</font></DIV></p><p><strong><font size="2" color="#000000">Too true Wayne.</font></strong></p><p><strong><font size="2" color="#000000">This must be taken advantage off. We will not have a spacecraft go by 'Santa' 2003 EL61 for many decades, so any help Mother Nature provides like this must be utilized.</font></strong></p><p><strong><font size="2" color="#000000">I wonder if we will finally get the rotational axis, rotational direction, etc. Perhaps spectral measurements could be done. I assume the other moon will not be undergoing transits & eclipses?</font></strong></p><p><strong><font size="2" color="#000000">Thanks Joel, very interesting. Please keep us informed.<br /><br />Andrew Brown.</font></strong></p> <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>
 
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h2ouniverse

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<p>hi all,</p><p>They have begun to refine orbits prediction. Unfortunately, the eclipse/transit season has already begun but the good news are that it may last until August.</p><p>http://www.cfa.harvard.edu/~fabrycky/EL61/</p><p>As a reminder, today is day#2454615</p><p>The first event on the table was last week. Next one is on May 31st, and the following on June 7th.</p>
 
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MeteorWayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>hi all,They have begun to refine orbits prediction. Unfortunately, the eclipse/transit season has already begun but the good news are that it may last until August.http://www.cfa.harvard.edu/~fabrycky/EL61/As a reminder, today is day#2454615The first event on the table was last week. Next one is on May 31st, and the following on June 7th. <br />Posted by h2ouniverse</DIV><br /><br />Once again, thanx for finding out about this and alerting us.</p><p>Many eyes and brains are better than one person's!</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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vogon13

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<p>At "Santa's" distance from the sun, and therefore it's slow angular rate of change for it's moon's orbital plane with reference to the fixed stars, is there any chance the earth might cross that plane again in a few months or next year ??&nbsp; </p><p>(think about it)&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>
 
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h2ouniverse

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>At "Santa's" distance from the sun, and therefore it's slow angular rate of change for it's moon's orbital plane with reference to the fixed stars, is there any chance the earth might cross that plane again in a few months or next year ??&nbsp; (think about it)&nbsp;&nbsp;&nbsp; <br />Posted by vogon13</DIV><br /><br />Thats a possibility indeed, as the apparent trajectory as seen from Earth makes a kind of elongated spring oblique-viewed drifting Eastwards. But Brown has said "til August" so I'm afraid that the orbital plane might not be well-placed as far as your vogonian suggestion is concerned.&nbsp;I hope you are right though because that would leave more time for them to well prepare the observations (instead of the current rush), get slots on big ground&space telescopes, enable FIR observations by Herschel (which is not yet launched), and avoid the Northern Summer here on Earth (with its damn-short nights!!!).</p><p>Also, the orbit of 2003el61-s2 ("Blitzen") is strongly influenced by 2003el61-s1 ("Rudolf") (one of the reasons why they came with such a late prediction) so may be orbit inclination will vary in the "good" direction.</p><p>Let's see.</p><p>Regards.</p>
 
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MeteorWayne

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<p>Just FYI, I have contacted the scope experts from the NJAA, to see if our 26" can be used to aid in this project should the timing work out.</p><p>From the JPL Ephemeris, it is about mag +17.4, so should be doable for us.</p><p>From the NJAA, the field transits about 9:20 PM, and sets after morning twilight, so is well placed for observation. (Jun 6-7)</p><p>It's on the Border between Bootes and Coma Berenices. ~ RA 13:33, Dec +19:51</p><p>Jody, Are you out there?</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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MeteorWayne

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<p>Santa's JPL Small-Body database browser (to see the object, you have to zoom way out :) )</p><p>http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2003%20EL61;orb=1;cov=0;log=0#orb</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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h2ouniverse

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<p>Some update on the campaign from site http://www.cfa.harvard.edu/~fabrycky/EL61/</p><p>"5/31/08 update:<br />DF and MH secured time on the Nordic Optical Telescope (NOT) for the first event listed in the circular. Unfortunately 100% humidity the whole night cancelled the run. Thanks to the good people at NOT for a lightning-fast and positive response to our urgent request!<br /><br />6/5/08 update:<br />DF and MH secured time on the Himalayan Chandra Telescope (HCT) in India for the egress of the second event (updated mid-time: June 7.65 UT)! This event is important because our model of the astrometry says it should certainly happen--no grazing here! This is a satellite-behind event, so we know that ~3% of the light will disappear (as opposed to satellite-in-front, in which the albedo of the region of EL61 that is occulted is what matters, so the expected depth of the event is guess-work). Therefore, if we get good time coverage and precision, we can expect to make a detection! An important science goal of these observations is probing the peculiar ellipsoidal shape of EL61 as inferred from photometric rotational modulation, which could be confirmed with geometrical constraints accessible via the timing of the satellite's occultation. The figures of equilibrium of rotating bodies was the subject of one of Chandrasekhar's books, so it is particularly fortuitous that the HCT is his namesake. (And, incidentally, DF is Chandra's academic great-grandson by way of Ostriker and Tremaine.) <br /><br />6/6/08 update:<br />To get coverage of the ingress too, DF contacted observers in Shanghai, Beijing, and Taiwan, all of which sent back positive responses, that they will try. The difficulty is typical poor weather (rainy) for some locations and city light in others. Looking ahead to the June 18 event, we hope to observe from Arizona for the ingress, and get people in Hawaii interested for the egress. "<br /></p>
 
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h2ouniverse

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<p>update from <font color="#5574b9">http://www.cfa.harvard.edu/~fabrycky/EL61/</font></p><p><em>"6/19/08 update:<br />Data was successful taken covering the predicted times of the "t2" event from India (by HCT; weather conditions were poor in East Asia) and of the "t3" event from Arizona (MDM's 2.4m with Retrocam, by Don Terndrup and Julie Djordjecic of the Ohio State University). These data are currently being processed, so nothing exciting or disappointing to report yet.<br />If others took observations that either saw events or can rule out events to some precision during some timespan, please notify us. You may, of course, publish the data on your own, but eventually a joint analysis of all data will give the best constraints."</em></p>
 
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h2ouniverse

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<p>M. Brown has recently given hints that primary and secondary eclipses of Namaka (2003EL61-2) by Haumea (2003EL61) should finally, in contrast with his recent fears that the eclipse season would end this Summer. Given that these seasons occur every half period of Haumea, these are good news for those of us who do not expect to be there in 2138!!!</p><p>http://www.mikebrownsplanets.com/2008/09/haumea.html</p><p>Quoting M. Brown: "In the past few months we have gotten a better orbital solution and we <em>think</em> the occultations might occur for a few more years (!). We will try again in the spring to see what we can see!"</p><p>This has been confirmed on the site: http://www.cfa.harvard.edu/~fabrycky/EL61/</p><p>one can read "Now we present mutual event mid-time predictions, based on the three-body model by Dan Fabrycky. The input data are only HST astrometry, given that there are now enough HST measurements to solve the orbits, and restricting ourselves to these cuts down on potential systematic errors. Independently, Darin Ragozzine constructed a model with a triaxial Haumea (including a J2 term), and predicts 2009 events up to ~2 hours earlier than the following predictions. We hope these will at least indicate which nights observers should aim for in observing proposals due in the fall. "</p><p>&nbsp;Also, Haumea's shadow should pass over Namaka</p>
 
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h2ouniverse

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<p>Next eclipse on Dec 9th.</p><p>Mike Brown has written this to explain why the eclipse season duration has been reassessed as longer than foreseen: "When we did our preliminary calculations in the spring we did the comparative simple job of considering Namaka in isolation. It took us the remainder of the summer to get a solution to the full problem, where we also figured out how the orbit of Namaka changes due to the gravitational influence of Hi&rsquo;iaka (&ldquo;us&rdquo; and &ldquo;we&rdquo; here is a euphemism for &ldquo;my graduate student Darin Ragozzine&rdquo; who actually did all of the work as part of his Ph.D. thesis). We knew there would be an effect, but we assumed early on that it would be a minor perturbation. It is, in a sense, a minor perturbation, but it makes all of the difference in the world.</p><p class="MsoNormal">Hi&rsquo;iaka ever-so-slightly twists the orbit of Namaka, slowly changing the direction it is pointing. It doesn&rsquo;t change by more than a degree or two a year &ndash; almost imperceptible! But, due to luck or fate or karma or cosmic design, it is changing it just enough to keep the orbit edge-on as seen from the earth for longer than usual. Normally the edge-on events would last for maybe two years. Because of Hi&rsquo;iaka, they are going to last <em>eight </em>years! So, OK, we have missed the first two years, but we have six more years of this to go!"<br /></p>
 
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MeteorWayne

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<p>Thanx oh bearer of water!!</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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