APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

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APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by APOD Robot » Wed May 22, 2019 4:11 am

Image Primordial Contact Binary 2014 MU69

Explanation: Primordial contact binary 2014 MU69, also known as Ultima Thule, really is very red. In fact, it's the reddest outer solar system object ever visited by a spacecraft from Earth. Its reddish hue is believed to be due to organic materials on its surface. Ruddy color and tantalizing surface details seen in this composite image are based on data from the New Horizons spacecraft recorded during the January 1 flyby of the farthest world yet explored. Embedded in the smaller lobe Thule (top), the 8 kilometer wide feature nick named Maryland crater is the largest depression known on the surface of Ultima Thule. Transmission of data collected from the flyby continues, and will go on until the late summer 2020 as New Horizons speeds deeper into the dim and distant Kuiper Belt.

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Ann » Wed May 22, 2019 7:06 am

Contact Binary 2014 MU69.
NASA, JHU’s APL, SwRI; Color Processing: Thomas Appéré.
Contact binary VFTS 352 in the Large Magellanic Cloud.
Illustration: ESO/L. Calçada.

















Two contact binaries. I, of course, prefer the blue one. :wink:
Extremetech wrote:
Astronomers at the ESO (the European Southern Observatory) have announced an astonishingly unusual find: A pair of double stars, dubbed VFTS 352, roughly 160,000 light years away in the Tarantula Nebula.
Each is classified as an O-type star — and O-type stars are the rarest main sequence stars in the universe, comprising just 0.00003% of known stars. They’re extremely prone to going supernova and collapsing into black holes or neutron stars. Finding two of them 12 million kilometers apart and actively merging, therefore, is something of a treat.
Right now, the stars of VFTS 352 are estimated to be sharing roughly 30% of their total mass between each other. No other overcontact binary is known to be this large or to share that great a percentage of its mass.
Right now, astronomers are predicting the star will die in one of two ways. Either the two stars will merge, forming a single giant and insanely unstable O-type star (possibly a hypergiant) before collapsing into a long-duration gamma ray burst (and incidentally, likely sterilizing every single planet within a non-trivial distance). Option #2 is explained by Selma de Mink of University of Amsterdam: “If the stars are mixed well enough, they both remain compact and the VFTS 352 system may avoid merging. This would lead the objects down a new evolutionary path that is completely different from classic stellar evolution predictions. In the case of VFTS 352, the components would likely end their lives in supernova explosions, forming a close binary system of black holes. Such a remarkable object would be an intense source of gravitational waves.”
Ultima Thule liten.png
Ultima Thule liten.png (4.03 KiB) Viewed 6653 times
And now I guess it's time to talk about the little red twoface. But I'll let someone else do that.

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by starsurfer » Wed May 22, 2019 9:17 am

Why can't someone send a space probe to the Oort Cloud?

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by neufer » Wed May 22, 2019 9:29 am

starsurfer wrote: Wed May 22, 2019 9:17 am
Why can't someone send a space probe to the Oort Cloud?
  • 1) Where exactly in the Oort Cloud?
    2) Why bother when the Oort Cloud regularly sends "space probes" to us?
https://en.wikipedia.org/wiki/Halley%27s_Comet wrote:

<<The orbits of the Halley-type comets suggest that they were originally long-period comets whose orbits were perturbed by the gravity of the giant planets and directed into the inner Solar System. If Halley was once a long-period comet, it is likely to have originated in the Oort cloud, a sphere of cometary bodies that has an inner edge of 20,000–50,000 AU.>>

:arrow: The nucleus of Halley's Comet, imaged by the Giotto probe in 1986. The dark coloration of the nucleus can be observed, as well as the jets of dust and gas erupting from its surface.
Last edited by neufer on Wed May 22, 2019 11:59 am, edited 1 time in total.
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by neufer » Wed May 22, 2019 9:52 am

radish.jpg
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APOD Robot wrote: Wed May 22, 2019 4:11 am
Explanation: Primordial contact binary 2014 MU69, also known as Ultima Thule, really is very red. In fact, it's the reddest outer solar system object ever visited by a spacecraft from Earth. Its reddish hue is believed to be due to organic materials on its surface. Ruddy color and tantalizing surface details seen in this composite image are based on data from the New Horizons spacecraft recorded during the January 1 flyby of the farthest world yet explored. Embedded in the smaller lobe Thule (top), the 8 kilometer wide feature nick named Maryland crater is the largest depression known on the surface of Ultima Thule. Transmission of data collected from the flyby continues, and will go on until the late summer 2020 as New Horizons speeds deeper into the dim and distant Kuiper Belt.
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by orin stepanek » Wed May 22, 2019 11:01 am

Ultima Thule reminds me of a fetus! I don't know why; it just does! :shock: It looks like it has eyes, a nose, and a mouth! :lol2: Organic material; wow! :D
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by De58te » Wed May 22, 2019 11:29 am

starsurfer wrote: Wed May 22, 2019 9:17 am Why can't someone send a space probe to the Oort Cloud?
We already are. Voyager 1 and 2 and New Horizons are on their way. Voyager 1 launched some 41 years ago is some 140 Astronomical Units away from the Sun. New Horizons is way behind at some 40 AU. The inner Oort Cloud is estimated to begin at 2,000 AU. Given if it took Voyager 1 some 40 years to travel 140 AU, it should reach the inner Oort Cloud in about (40 times 14) 560 years. Unfortunately Voyager 1's power will only last some 20 more years so when it gets to the Oort Cloud it will be dead.

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by NCTom » Wed May 22, 2019 11:42 am

I am showing my ignorance here, but I am a little surprised we have this much clarity of surface detail with the sun so far away. Is there simply more light than I had expected at this distance or is this the result of a longer photo exposure?

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Chris Peterson » Wed May 22, 2019 1:21 pm

NCTom wrote: Wed May 22, 2019 11:42 am I am showing my ignorance here, but I am a little surprised we have this much clarity of surface detail with the sun so far away. Is there simply more light than I had expected at this distance or is this the result of a longer photo exposure?
Sunlight there is about 2000 times less bright than on Earth. Brighter than twilight, a bit dimmer than a you'd have during a very dark thunderstorm. So, plenty of light for a modern image sensor without requiring a long exposure.
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Chris Peterson » Wed May 22, 2019 1:23 pm

starsurfer wrote: Wed May 22, 2019 9:17 am Why can't someone send a space probe to the Oort Cloud?
As noted, we do have probes heading that way. But it's very far away, and it's very low density. A probe could spend thousands of years passing through, and would probably never get close enough to an object to image or detect it. And we don't have enough knowledge to know where any individual Oort cloud object is to even target one.
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by sillyworm 2 » Wed May 22, 2019 2:03 pm

Am I alone pondering the lack of any real advanced information shared concerning Ultima Thule? I feel a little underwhelmed considering how excited I was/am about the mission.Hopefully some tantilizing info soon...I prefer the binary star(thanks Ann) over the double turnip/radish(?)..Maybe because I just ate lunch...

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Fred the Cat » Wed May 22, 2019 2:15 pm

Passing by Ultima Thule was a real " tweet" for lots of people. :ssmile:
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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by JohnD » Wed May 22, 2019 2:59 pm

Ann wrote: Wed May 22, 2019 7:06 am Two contact binaries. I, of course, prefer the blue one. :wink:
Extremetech wrote:
Astronomers at the ESO (the European Southern Observatory) have announced an astonishingly unusual find: A pair of double stars, dubbed VFTS 352, roughly 160,000 light years away in the Tarantula Nebula.
Each is classified as an O-type star — and O-type stars are the rarest main sequence stars in the universe, comprising just 0.00003% of known stars. They’re extremely prone to going supernova and collapsing into black holes or neutron stars. Finding two of them 12 million kilometers apart and actively merging, therefore, is something of a treat.
Right now, the stars of VFTS 352 are estimated to be sharing roughly 30% of their total mass between each other. No other overcontact binary is known to be this large or to share that great a percentage of its mass.
Right now, astronomers are predicting the star will die in one of two ways. Either the two stars will merge, forming a single giant and insanely unstable O-type star (possibly a hypergiant) before collapsing into a long-duration gamma ray burst (and incidentally, likely sterilizing every single planet within a non-trivial distance). Option #2 is explained by Selma de Mink of University of Amsterdam: “If the stars are mixed well enough, they both remain compact and the VFTS 352 system may avoid merging. This would lead the objects down a new evolutionary path that is completely different from classic stellar evolution predictions. In the case of VFTS 352, the components would likely end their lives in supernova explosions, forming a close binary system of black holes. Such a remarkable object would be an intense source of gravitational waves.”
Ann
Ann,
Two stars, 12 million miles apart, yet actively merging and already sharing 30% of their mass? And you can show us a sharp image of that situation from 160,000 light years away? Surely those two stars will be in orbit around each other with a very short period? So short that a snap shot would show a blur? And if their surfaces are in contact, they must be collapsing (or were 160K years ago) into each other, like the famous merging Black Holes we've heard about?
I feel as if you are joking, this story sounds so unlikely! But you're Ann, the Queen of Colour! A serious person, who might do an April Fool, but not at the end of May!
John
PS just looked up the diameter of a typical O-type star. They are so enormous that centres 12M miles apart would make them merge! My mistake! (Ignorance!) But what aboit the rest of my comments? Equally ignorant? Please teach!

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Yup » Wed May 22, 2019 3:55 pm

JohnD wrote: Wed May 22, 2019 2:59 pm Ann,
Two stars, 12 million miles apart, yet actively merging and already sharing 30% of their mass? And you can show us a sharp image of that situation from 160,000 light years away? Surely those two stars will be in orbit around each other with a very short period? So short that a snap shot would show a blur? And if their surfaces are in contact, they must be collapsing (or were 160K years ago) into each other, like the famous merging Black Holes we've heard about?
I feel as if you are joking, this story sounds so unlikely! But you're Ann, the Queen of Colour! A serious person, who might do an April Fool, but not at the end of May!
John
PS just looked up the diameter of a typical O-type star. They are so enormous that centres 12M miles apart would make them merge! My mistake! (Ignorance!) But what aboit the rest of my comments? Equally ignorant? Please teach!
Actually it's 12 million kilometers (or 7.5 million miles). Cozy!

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Ann » Wed May 22, 2019 4:28 pm

JohnD wrote: Wed May 22, 2019 2:59 pm Ann,
Two stars, 12 million miles apart, yet actively merging and already sharing 30% of their mass? And you can show us a sharp image of that situation from 160,000 light years away? Surely those two stars will be in orbit around each other with a very short period? So short that a snap shot would show a blur? And if their surfaces are in contact, they must be collapsing (or were 160K years ago) into each other, like the famous merging Black Holes we've heard about?
I feel as if you are joking, this story sounds so unlikely! But you're Ann, the Queen of Colour! A serious person, who might do an April Fool, but not at the end of May!
John
PS just looked up the diameter of a typical O-type star. They are so enormous that centres 12M miles apart would make them merge! My mistake! (Ignorance!) But what aboit the rest of my comments? Equally ignorant? Please teach!
Hi, John! :D

Contact binary VFTS 352 in the Large Magellanic Cloud.
Illustration: ESO/L. Calçada.
The center of the massive R136a cluster in the Tarantula Nebula.
ESO/P. Crowther/C.J. Evans

















Please note that the picture of the contact binary is an artist's illustration, not an actual photo. Why not?

Take a look at the picture at right, which shows us the center of the crowded R136a supercluster at the heart of the Tarantula Nebula. To my knowledge, this rather blurry (infrared) picture is the best picture we have got of individual stars in the Tarantula Cluster. (Of course, there is certainly this visula light Hubble picture too - by NASA, ESA, F. Paresce, R. O'Connell, and the Wide Field Camera 3 Science Oversight Committee - http://hubblesite.org/newscenter/archiv ... 2/image/a/ - but as you can see, in the visual light Hubble picture the stars are not better separated than in the ESO/P. Crowther/C.J. Evans one.)

So, long story short: Even relatively wide binaries are not easy to spot in the Tarantula Nebula, which is 160,000 light-years away. And remember that VFTS 352 is an extremely tight contact binary. In my opinion, you wouldn't be able to actually photograph the two components of such a tight contact binary even if they were as close to us as Proxima Centauri, the closest star to us in the sky after the Sun. (But I might be wrong about being unable to photographically separate such contact binaries in visual light if they are as close as Proxima Centauri, so Chris, Art, Geck, anyone, correct me.)

The stars of the contact binary VFTS 352 are 12 million kilometers apart, not 12 million miles. The diameter of the Sun is 1,391,000 kilometers, and while I had some trouble finding information on the typical diameter of a main sequence O-type star, I found some info on the O9V star 10 Lacertae. The diameter of 10 Lacertae is, according to John Kaler, 4.7 times that of the Sun, and if the two components of VFTS 352 are similar in size to 10 Lacertae, their diameters would be about 6.5 million kilometers. Clearly then, if they are separated by only 12 million kilometers, it seems inevitable that they would "touch".

Note that one of both of the components of VFTS 352 may well be larger than 10 Lacertae, because 10 Lac may well be small as O-type stars go. At any rate, 10 Lac is indeed relatively light-weight as O stars go, only 16 solar masses, according to Jim Kaler. The two components of VFTS 352 pack a combined mass of 57 times solar.

The question is, how did the scientist find this star? The only way for them to know that it is a binary star is to look at its spectrum. At left you can see a typical spectrum of a spectroscopic binary star, where the spectrum alone tells us that the star is a binary. (Unfortunately I wasn't able to extract more information from the page where the picture was posted.)

I would guess, too, that the stars of VFTS 352 would be orbiting each other very rapidly. That would make their spectral lines broad and possibly blurred.

How, though, would scientists know that the components of VFTS 352 are only 12 million kilometers apart? You've got me there, I'm afraid. My best guess - and that is a guess, mind you - is that the mere act of physically interacting with another star will alter a star's spectrum.







Artist's impression of Beta Lyrae.


















One of the most famous contact binaries in the nearby sky is Beta Lyra. This is what Wikipedia says about this interacting star pair:
Wikipedia wrote:
Beta Lyrae Aa is a semidetached binary system made up of a stellar class B7 main sequence primary star and a secondary that is probably also a B-type star. The fainter, less massive star in the system was once the more massive member of the pair, which caused it to evolve away from the main sequence first and become a giant star. Because the pair are in a close orbit, as this star expanded into a giant it filled its Roche lobe and transferred most of its mass over to its companion. The secondary, now more massive star is surrounded by an accretion disk from this mass transfer, with bipolar, jet-like features projecting perpendicular to the disk.[2] This accretion disk blocks humans' view of the secondary star, lowering its apparent luminosity and making it difficult for astronomers to pinpoint what its stellar type is. The amount of mass being transferred between the two stars is about 2 × 10−5 solar masses per year, or the equivalent of the Sun's mass every 50,000 years, which results in an increase in orbital period of about 19 seconds each year. The spectrum of Beta Lyrae shows emission lines produced by the accretion disc. The disc produces around 20% of the brightness of the system.
The variable luminosity of this system was discovered in 1784 by the British amateur astronomer John Goodricke.[23] The orbital plane of this system is nearly aligned with the line of sight from the Earth, so the two stars periodically eclipse each other. This causes Beta Lyrae to regularly change its apparent magnitude from +3.2 to +4.4 over an orbital period of 12.9414 days. The two components are so close together that they cannot be resolved with optical telescopes, forming a spectroscopic binary. In 2008, the primary star and the accretion disk of the secondary star were resolved and imaged using the CHARA Array interferometer[24] and the Michigan InfraRed Combiner (MIRC)[25] in the near infrared H band (see video below), allowing the orbital elements to be computed for the first time.
If the orbital plane of VFTS 352 is aligned with the line of sight of the Earth, its apparent luminosity would certainly be variable from the Earth's point of view.

To summarize: It is impossible to photograph the two components of VFTS 352 in visual light, and it is almost certainly impossible to separate them in infrared light, too. But there are very many hot massive stars in the Tarantula Nebula, and scientists would easily be able to tell that VFTS 352 is just one more of them. The spectrum of this binary would give away its binary nature, and quite possibly the stars would be surrounded by accretion disks of material which they have stolen from each other. (If the accretion disks emit visual light, their spectra would be different than the spectra from the stars.) The binary might well vary in luminosity due to its binary nature (where one component eclipses the other one, completely or partly).

My best guess as to how scientists claim to know that the two components are only 12 million kilometers apart is that they can see from the stars' spectra that they are both main sequence O-type stars and that they are definitely exchanging mass. That gives the scientists a relatively good handle on the stars' true sizes, and if they are indeed interacting and exchanging matter, they can't be separated by a lot more than about 12 million kilometers.

But I'm guessing. Sorry.

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by JohnD » Wed May 22, 2019 6:36 pm

Thank you, Ann, for that comprehensive tutorial!

An accretion disc! Around two stars that are touching! As they approached, then the matter in their discs nearest to each other would have been moving in opposite directions! The combined speed on impact would have been doubled, surely enough for enormous energy release. And unless their rotations were opposite then the same will apply to the area of contact.


And once that happens, how long can they continue to scrape away at each other? The impact above must slow their orbits, accelerating their mutual approach, causing more impaction and precipitating their fusion after a relatively short time to a star's age! Wow! Fireworks in our lifetimes?

John

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Re: APOD: Primordial Contact Binary 2014 MU69 (2019 May 22)

Post by Ann » Thu May 23, 2019 3:44 am

JohnD wrote: Wed May 22, 2019 6:36 pm Thank you, Ann, for that comprehensive tutorial!

An accretion disc! Around two stars that are touching! As they approached, then the matter in their discs nearest to each other would have been moving in opposite directions! The combined speed on impact would have been doubled, surely enough for enormous energy release. And unless their rotations were opposite then the same will apply to the area of contact.


And once that happens, how long can they continue to scrape away at each other? The impact above must slow their orbits, accelerating their mutual approach, causing more impaction and precipitating their fusion after a relatively short time to a star's age! Wow! Fireworks in our lifetimes?

John
Thanks, but remember that I'm guessing.

But the text where I found my info called the stars of VFTS 352 "hyperactive and unstable". We don't normally expect O-type stars to be unstable, but it makes sense that these two are, just because of their insane proximity. Remember that all O-type stars blow a fierce wind, and these winds are going to collide in the VFTS 352 system. Their winds alone might cause these stars to exchange matter and act up.

Famous luminous blue giant Eta Carina in the Milky Way is also an interacting binary, although the components of Eta are much more widely separated than the components of VFTS 352. Also Eta Carina is a much more massive binary that VFTS 352, since the components of Eta Car are 30 and 90 times the mass of the Sun, versus a combined mass of 57 times solar for the components of VFTS 352.

So when will VFTS 352 go supernova? That is actually impossible to say, but chances are that it won't happen in our lifetimes. Remember that even O-type stars live longer than the current history of humanity.

Check out the video of Eta Carina's binary nature:

Click to play embedded YouTube video.

Ann
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