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PostPosted: Mon Nov 06, 2017 6:38 pm 
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I've moved this out of the meteorite thread since it never landed on earth.

Anyway, our first known interstellar visitor prompted a new naming scheme from the IAU as described in...

MPEC 2017-V17 : NEW DESIGNATION SCHEME FOR INTERSTELLAR OBJECTS

Quote:
Provisional designations for interstellar objects will be handled using the C/ or A/ prefix (as appropriate), with the designation using the comet system.

Accordingly, the object A/2017 U1 receives the permanent designation 1I and the name 'Oumuamua. The name, which was chosen by the Pan-STARRS team, is of Hawaiian origin and reflects the way this object is like a scout or messenger sent from the distant past to reach out to us ('ou means reach out for, and mua, with the second mua placing emphasis, means first, in advance of).

Correct forms for referring to this object are therefore: 1I; 1I/2017 U1; 1I/'Oumuamua; and 1I/2017 U1 ('Oumuamua).

This first interstellar object is being handled as a special case. A small committee of the WGSBN will be created to codify the circumstances under which an object will quality for an I-number and the rules that will apply to the names, bearing in mind the precedent set by this case. A formal report will follow their deliberations.

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PostPosted: Tue Nov 07, 2017 7:23 pm 
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Bump for Joe!

Also:

Planetary Society asteroid hunter snags picture of interstellar visitor ʻOumuamua

http://www.planetary.org/blogs/jason-da ... pient.html

Quote:
One week after the discovery, asteroid hunter Luca Buzzi tracked ʻOumuamua from northern Italy with a 50-minute image exposure on October 26. In an email, Buzzi said he fought thin cirrus clouds to barely pull the asteroid above the visual threshold using his 0.84-meter telescope and Planetary Society-funded CCD camera. He ordinarily uses the equipment to track potentially hazardous near-Earth asteroids.


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PostPosted: Wed Nov 08, 2017 1:02 am 
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The name has been a source of comment and complaint on the Minor Planet Mailing List.

First, a number of posters wondered about the diacritical mark at the beginning of the name, mainly because it might cause problems with alphabetical sorting and searching. In the Hawaiian language, the mark is technically an 'okina, which indicates a glottal stop. See...

https://www.hawaii.edu/site/info/diacritics.php

Per Dave Tholen, an astronomer with the Institute for Astrophysics, University of Hawai'i, the new name is pronounced: owe moo-uh moo-uh

Second, and perhaps a greater problem, is the use of an uppercase "i" to indicate "Interstellar" in the designation, in this case "1I." The problem is that it can easily be confused with the number "1," a lowercase "L" or an uppercase letter "i" depending on the typeface. There was a suggestion that they should have used a less-confusing uppercase "E" to indicate "Extrasolar."

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PostPosted: Tue Nov 14, 2017 1:55 pm 
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An Origin for a Far Traveling Asteroid

https://www.centauri-dreams.org/?p=38782

Quote:
We suggest that A/2017 U1 formed in a protoplanetary disk in the Carina/Columba associations and was ejected by a planet ≈40 Myr ago. The absence of ice indicates an origin inside the “ice line” of the disk plus an ejection velocity of 1-2 km sec−1 (assuming the cluster was already unbound), constrain the mass mP and semi-major axis aP of the planet.

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PostPosted: Mon Nov 20, 2017 12:59 pm 
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Solar System’s First Interstellar Visitor Dazzles Scientists

https://www.nasa.gov/feature/solar-syst ... scientists

I am tickled by NASA mentioning this object is 'cigar-shaped'.

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PostPosted: Mon Nov 20, 2017 2:05 pm 
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Is 1I/2017 U1 Really of Interstellar Origin?

http://iopscience.iop.org/article/10.38 ... a9af2/meta

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PostPosted: Mon Nov 20, 2017 2:06 pm 
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I found a really good paper about 'Oumuamua.


Attachments:
10.1038@nature25020.pdf [2.05 MiB]
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PostPosted: Fri Nov 24, 2017 7:17 pm 
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Centauri Dreams has a few good articles on 'Oumuamua

Shards, Axis Ratios and Interstellar Objects

https://www.centauri-dreams.org/?p=38854

Unusual Visitor: A Deeper Look at ‘Oumuamua

https://www.centauri-dreams.org/?p=38834

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PostPosted: Fri Nov 24, 2017 7:18 pm 
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`Oumuamua: Listening To An Interstellar Interloper

https://www.centauri-dreams.org/?p=38844

...and Discover Magazine chimes in.

That Interstellar Asteroid is Pretty Strange. Could It Be…?

http://blogs.discovermagazine.com/outth ... d-mystery/

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PostPosted: Fri Dec 01, 2017 9:02 am 
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1I/'Oumuamua is tumbling

http://lanl.arxiv.org/abs/1711.11530

Quote:
The discovery of 1I/2017 U1 ('Oumuamua) has provided the first glimpse of a planetesimal born in another planetary system. This interloper exhibits a variable colour, within a range that is broadly consistent with local small bodies such as the P/D type asteroids, Jupiter Trojans, and dynamically excited Kuiper Belt Objects. 1I/'Oumuamua appears unusually elongated in shape, with an axial ratio exceeding 5:1. Rotation period estimates are inconsistent and varied, with reported values between 6.9 and 8.3 hours. Here we analyse all reliable optical photometry reported to date. No single rotation period can explain the exhibited brightness variations. Rather, 1I/'Oumuamua appears to be in an excited rotational state undergoing Non-Principal Axis (NPA) rotation, or tumbling. A satisfactory solution has apparent lightcurve frequencies of 0.135 and 0.126 hr-1 and implies a longest-to-shortest axis ratio of 5:1, though the available data are insufficient to uniquely constrain the true frequencies and shape. Assuming a body that responds to NPA rotation in a similar manner to Solar System asteroids and comets, the timescale to damp 1I/'Oumuamua's tumbling is at least a billion years. 1I/'Oumuamua was likely set tumbling within its parent planetary system, and will remain tumbling well after it has left ours.


One remark on Twitter:

https://twitter.com/erinleeryan/status/ ... 1917884416

Quote:
Nope, tumbling isn’t a thing for most asteroids. Most are orderly principal axis rotators.


If 'Oumuamua is tumbling and rotating along two axes, it's stranger than imagined.

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PostPosted: Sun Dec 03, 2017 11:28 am 
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The Physics Behind the Strange Interstellar Asteroid 'Oumuamua

https://www.wired.com/story/the-physics ... -oumuamua/

Also check out the December issue of Astral Projections, as I wrote an article on this interstellar interloper.

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PostPosted: Tue Dec 05, 2017 8:03 pm 
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It's happened -- 1I/'Oumuamua has been confused with 1P/Halley, by the Minor Planet Center of all folks! Here's a bit of the thread from the Comet Mailing List...

Quote:
I noticed that 1P/Halley has been observed on November 17th, at 24.3 mag

http://www.minorplanetcenter.org/iau/lists/LastCometObs.html

Does anybody know what is going on?

1P/Halley 2017 11 17.18 24.3 G H01

Daniel [Peter]
--------------------

Hi Daniel, and all,

I’ll bet this is actually referring to the observation of 1I/‘Oumuamua that’s listed on MPEC W75, and one of the automated routines at the MPC didn’t interpret the designation correctly.

Sincerely,
Alan [Hale, of Comet Hale-Bopp fame]

Although magnitude 24.3 is dim, it's about 4 to 5 magnitudes brighter than one would expect for 1P/Halley at this time as it nears aphelion. Hence the original puzzlement about the magnitude. The error has evidently been recognized. If you follow the link to the MPC page, 1P/Halley is no longer present.

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PostPosted: Wed Dec 06, 2017 11:14 am 
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The bureaucrats at Pan-STARRS and the IAU have created quite a mess by not keeping things simple and by embracing cultural outreach. Good for job security, I suppose; correcting the problems gives them something to do.

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PostPosted: Mon Dec 11, 2017 9:39 am 
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Alien Probe or Galactic Driftwood? SETI Tunes In to 'Oumuamua

https://www.scientificamerican.com/arti ... -oumuamua/

Quote:
It’s a long shot, but scientists are about to listen very closely for radio signals from our solar system’s first known interstellar visitor


If 'Oumuamua is artficial and capable of communicating, why radio?

And Jason "Megastructure" Wright of Penn State gives his 2¢ on the spacecraft zeitgeist.

Is 1I/’Oumuamua an Alien Spacecraft?

http://sites.psu.edu/astrowright/2017/1 ... pacecraft/

Quote:
No, I don’t think there’s any reason to think it is, but there’s lots of chatter on Twitter that suggest astronomers think it could be

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PostPosted: Wed Dec 13, 2017 10:17 am 
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Oddball Object Tumbling among the Stars Could Disrupt Planetary Science

https://www.scientificamerican.com/arti ... y-science/

Quote:
The solar system’s first-observed interstellar emissary hints at undiscovered populations of exoplanets and violent origins

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PostPosted: Wed Dec 13, 2017 12:22 pm 
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A Glimpse of Oumuamua

https://www.nytimes.com/video/science/1 ... uamua.html

Video at link.

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PostPosted: Fri Dec 15, 2017 10:15 pm 
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Courtesy of Wikipedia.


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PostPosted: Sat Dec 16, 2017 1:20 am 
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Chris,

A constructive comment about the excessively large pictures you've been posting recently. They really mess up the page they're on and they're also hard to see. The current picture of 'Oumuamua's track you posted is 4986 x 4674 pixels and required extensive scrolling to see all of it on my screen, or setting the browser window at 30% to see all of it at once.

For the attached version here, I reduced the size to 1200 x 1125 pixels, which better fits the window (I didn't have to scroll the preview on my screen to see it all) while still leaving most details legible. If necessary, you could include a link to the original full-size picture to see the finest details. In this case...

https://upload.wikimedia.org/wikipedia/commons/4/41/Oumuamua-skypath.png

BTW, the spiraling path is reminiscent of comets coming from a distance. The movement forming the loops is caused by parallax as viewed from opposite sides of the earth's orbit over the course of a year. For example, look at the path of comet C/2017 O1 (ASASSN) on Seiichi Yoshida's page...

http://www.aerith.net/comet/catalog/2017O1/2017O1.html


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PostPosted: Sat Dec 16, 2017 8:25 am 
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The astoundingly large images I've been posting are of expediency and necessity.

1. If I hotlink to an image off the board, the board nags me "This needs to be 600x600, among other outdated specs for images."

2. Directly uploading the image, confusingly, bypasses the message board's specifications.

3. I'm lazy.

4. ctrl plus and ctrl minus will enlarge or shrink the browser screen.

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PostPosted: Sat Dec 16, 2017 12:50 pm 
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Also, one may need to use a mouse to drag the righthand side of the image further to the right.

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PostPosted: Mon Dec 18, 2017 11:36 am 
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Interstellar object ‘Oumuamua covered in 'thick crust of carbon-rich gunk'

https://www.theguardian.com/science/201 ... -rich-gunk

Quote:
Cigar-shaped body has a deep surface layer made of organic ices baked in interstellar radiation – and potentially has ice in its heart, say astronomers


Or as I called it this morning, potential cosmic roadkill.

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PostPosted: Mon Dec 18, 2017 3:16 pm 
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'Oumuamua Probably Isn't a Spaceship—But It Could Have Passengers

https://www.wired.com/story/oumuamua-pr ... assengers/

Quote:
Today in the journal Nature Astronomy, astronomers report observations that suggest 'Oumuamua is encased in a dry, carbon-rich crust that could have protected a water-ice core from being vaporized as it made a close pass of our sun earlier this year. You can almost think of it as the hull of a spaceship.

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PostPosted: Mon Jan 15, 2018 3:42 pm 
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Spectroscopy and Thermal Modelling of the First Interstellar Object 1I/2017 U1 ‘Oumuamua

http://www.astrowatch.net/2018/01/spect ... ng-of.html

Quote:
"We've discovered that this is a planetesimal with a well-baked crust that looks a lot like the tiniest worlds in the outer regions of our solar system, has a greyish/red surface and is highly elongated, probably about the size and shape of the Gherkin skyscraper in London.


The Gherkin:


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PostPosted: Thu Feb 08, 2018 1:46 pm 
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The Solar System Probably has Thousands of Captured Interstellar Asteroids

https://www.universetoday.com/138494/so ... asteroids/

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PostPosted: Mon Feb 12, 2018 11:52 am 
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'Oumuamua had a violent past and has been tumbling around for billions of years

https://phys.org/news/2018-02-oumuamua- ... years.html

Quote:
"While we don't know the cause of the tumbling, we predict that it was most likely sent tumbling by an impact with another planetesimal in its system, before it was ejected into interstellar space."

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