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NASA Citizen Scientists Spot Object Moving 1 Million Miles Per Hour (nasa.gov) 58
Citizen scientists from NASA's Backyard Worlds: Planet 9 project discovered a hypervelocity object, CWISE J1249, moving fast enough to escape the Milky Way. "This hypervelocity object is the first such object found with the mass similar to or less than that of a small star," reports NASA's Science Editorial Team, suggesting the object may have originated from a binary star system or a globular cluster. From the report: A few years ago, longtime Backyard Worlds citizen scientists Martin Kabatnik, Thomas P. Bickle, and Dan Caselden spotted a faint, fast-moving object called CWISE J124909.08+362116.0, marching across their screens in the WISE images. Follow-up observations with several ground-based telescopes helped scientists confirm the discovery and characterize the object. These citizen scientists are now co-authors on the team's study about this discovery published in the Astrophysical Journal Letters (a pre-print version is available here). CWISE J1249 is zooming out of the Milky Way at about 1 million miles per hour. But it also stands out for its low mass, which makes it difficult to classify as a celestial object. It could be a low-mass star, or if it doesn't steadily fuse hydrogen in its core, it would be considered a brown dwarf, putting it somewhere between a gas giant planet and a star.
Ordinary brown dwarfs are not that rare. Backyard Worlds: Planet 9 volunteers have discovered more than 4,000 of them! But none of the others are known to be on their way out of the galaxy. This new object has yet another unique property. Data obtained with the W. M. Keck Observatory in Maunakea, Hawaii, show that it has much less iron and other metals than other stars and brown dwarfs. This unusual composition suggests that CWISE J1249 is quite old, likely from one of the first generations of stars in our galaxy. Why does this object move at such high speed? One hypothesis is that CWISE J1249 originally came from a binary system with a white dwarf, which exploded as a supernova when it pulled off too much material from its companion. Another possibility is that it came from a tightly bound cluster of stars called a globular cluster, and a chance meeting with a pair of black holes sent it soaring away.
Ordinary brown dwarfs are not that rare. Backyard Worlds: Planet 9 volunteers have discovered more than 4,000 of them! But none of the others are known to be on their way out of the galaxy. This new object has yet another unique property. Data obtained with the W. M. Keck Observatory in Maunakea, Hawaii, show that it has much less iron and other metals than other stars and brown dwarfs. This unusual composition suggests that CWISE J1249 is quite old, likely from one of the first generations of stars in our galaxy. Why does this object move at such high speed? One hypothesis is that CWISE J1249 originally came from a binary system with a white dwarf, which exploded as a supernova when it pulled off too much material from its companion. Another possibility is that it came from a tightly bound cluster of stars called a globular cluster, and a chance meeting with a pair of black holes sent it soaring away.
That's slow (Score:2)
That's about 1/669th the speed of light. From Earth at that speed it would take over 2500 years to reach the nearest star.
It's actually fast (Score:2)
At that speed, you need only a few minutes to reach the Moon from Earth.
Re: (Score:2)
Not even that long [youtube.com].
Re: That's slow (Score:5, Funny)
I believe that you need less than four days to reach the nearest star from Earth at this speed.
Re: That's slow (Score:2)
Excuse me?
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Excuse me?
Hint: If you want to know which start he's talking about you need to go looking for it at daytime.
Re: That's slow (Score:1)
Re: That's slow (Score:5, Funny)
Poxima Centauri is earth's second closest star. There's a better known one somewhat closer. :)
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The Sun is closer than many, many other stars.
The geeks in the room burst out laughing for a second at this., and that was back when we respected our teachers.
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That's about 1/669th the speed of light. From Earth at that speed it would take over 2500 years to reach the nearest star.
Keep in mind planet Earth is moving around the Sun at 67,000 mph (relatively speaking although). That's probably why they consider 1 million mph fast, relatively speaking as well.
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Thank you. I'm surprised they did not tell us its speed in furlongs per fortnight.
Units (Score:5, Informative)
Miles per hour is not an astronomical measurement.
It works out to 447 Kilometres per second
Still that is pretty fast
Re: Units (Score:2)
Also, what miles are we talking about here? Because, do astronauts use nautical miles? :P
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Also, what miles are we talking about here? Because, do astronauts use nautical miles? :P
Those with any horse sense use furlongs per fortnight. :-)
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The IAU has always used SI (metric) units. They are the basis for the System of Astronomical Constants. [wikipedia.org] The headline is wrong, and so are you. Go be mad elsewhere.
Re: Units (Score:2)
Exactly, thanks for converting that!
For reference: the planets go around the sun in tens of km/s, the sun orbits the center of the milky way in about 200km/s. That is why km/s is a proper unit here.
"Millions of miles per hour" is a populist way of saying "much faster than your car" to a marginal fraction of the planet.
Re:Units (Score:5, Funny)
Miles per hour is not an astronomical measurement.
To put this into proper units - the object is traveling approximately 2687994655.2242 furlongs per fortnight.
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A bit of amusing irony about that statement: Much of the work of traditional astronomy was done in the cgs system - centimeters, grams, seconds. So folks were metricating light-years in centimeters and stellar masses in grams. lol
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Miles per hour is not an astronomical measurement.
It works out to 447 Kilometres per second
Still that is pretty fast
If this were the 1920s, your character would be humorously portrayed as starting each sentence with "Acktually ..."
Re: Units (Score:1)
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Sweet. Does anyone know what it works out in Libraries of congress per second? :p
Extragalactic? (Score:5, Interesting)
Re: (Score:3)
Yes, it may be from outside the Milky Way and just passing through.
That's more likely than some of the conjectures in TFA:
1. It was not ejected from a binary system. Binary systems are stable. Ejections only happen from systems with three or more stars.
2. It was not accelerated by a companion supernova. A supernova or hypernova could not have accelerated a companion star to that velocity without blowing it apart.
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It was not ejected from a binary system. Binary systems are stable. Ejections only happen from systems with three or more stars.
Wrong [washington.edu].
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Wrong [washington.edu].
Your link is about binary star systems ejecting planets, not one of the stars.
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"if it doesn't steadily fuse hydrogen in its core, it would be considered a brown dwarf, putting it somewhere between a gas giant planet and a star."
Given a binary star system with actual stars, something of lower mass can be ejected. The stars stay, the brown dwarf goes.
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Yes, it may be from outside the Milky Way and just passing through.
That's more likely than some of the conjectures in TFA:
1. It was not ejected from a binary system. Binary systems are stable. Ejections only happen from systems with three or more stars.
2. It was not accelerated by a companion supernova. A supernova or hypernova could not have accelerated a companion star to that velocity without blowing it apart.
Traveling through hyperspace ain't like dustin' crops boy! Without precise calculations you could fly right through a star or bounce too close to a supernova and that'd end your journey real quick, wouldn't it?
~Hans Solo [youtube.com]
Re: Extragalactic? (Score:2)
Re: (Score:2)
Re: Extragalactic? (Score:2)
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Pierson's Puppeteers? (Score:3)
A third possibility is that it's Pierson's Puppeteers escaping the exploding galactic core.
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dude that's like the 100 trillionth possibility.
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Oh for mod points (Score:2)
Thanks for a great suggestion!
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Totally not a (Score:2)
Manhole cover.
Riddick's space ship (Score:2)
Expect Necromongers to follow.
Relative to what? (Score:2)
I mean, 1e6 MPH relative to the last asteroid to drift through these parts, 1e6 MPH relative to Sol, 1e6 MPH relative to Sagittarius? They're (slightly) different things. Nothing in the universe moves relative to itself.
I know, I'm just being pedantic. When the summary is clearly written to sensationalize, it's sometimes hard to see how mundane the event being sensationalized truly is. Solar systems eject planets as part of their formation process (due to collisions, I think?). It doesn't take a great
Re:Relative to what? (Score:5, Informative)
"Moderate resolution spectroscopy with Keck/NIRES reveals it to be a metal-poor early L subdwarf with a large radial velocity (103±10 km/s), and its estimated distance of 125±8 pc yields a speed of 456±27 km/s in the Galactic rest frame, near the local escape velocity for the Milky Way. " -- https://arxiv.org/html/2407.08... [arxiv.org]
Wikipedia says there 20 Hypervelocity stars (HSV) were observed in the Milky Way, and 1000 could exist https://en.wikipedia.org/wiki/... [wikipedia.org] in particular https://en.wikipedia.org/wiki/... [wikipedia.org] has a velocity of 709 km/s
Thank you. (Score:2)
With apologies, next time I'll do my own research. Again, thanks.
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As usual, it's the slashdot summary that is lacking. Your question was very relevant and searching for the information made me learn new things as well.
Rendez-vous with Rama? (Score:2)
After all, it's only 10 times faster and that was a long time ago.:-)
George Jetson (Score:1)
outrunning the Space Speed Patrol
Can someone calculate... (Score:2)
In other words how far can we see an object with such brightness?