## Oumuamuo

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### Oumuamuo

Hi everyone I have just watched the sky at night program about oumuamuo and I do not understand it’s trejectory on the tv programme it is shown as a large u shape through our solar system I do not understand how it can be a u shape??? Why isn’t it a mostly straight trajectory’ through our space how can it be a u shape could someone please explain in simple terms that I might be able to understand thanks in advance Douglas
Dougy broon

Posts: 2
Joined: Mon Feb 12, 2018 8:25 am

### Re: Oumuamuo

It has come in from outside the Solar System, effectively starting off travelling in a straight line. As it nears the Sun, its trajectory is affected by the gravitational attraction, and is bent into a hyperbola. The fact that it's a hyperbola rather than an ellipse is how we know it's from outside the Solar System. The exact shape depends on its initial speed of approach and how close to the Sun it gets.
It's not an exact U shape of course, more like a curved V
Scopes: Meade 8" SCT, Skywatcher 127mm Mak, Raffle winner of SW ST80
For imaging: Pentax K5, Asda webcam, Star Adventurer (new toy)
For companionship: Mid Cheshire Astronomical Group.
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Gfamily2

Posts: 516
Joined: Thu Jun 25, 2015 10:38 pm

### Re: Oumuamuo

Just to put it another way. Oumuamuo's path was a straight line before it came near to the sun. Just like the sun's gravity makes the planets go around in orbits, when Oumuamuo approached the sun, the sun's gravity tried to make it go around in an orbit too. However, Oumuamuo was going too fast for the sun to do that. The best the sun could do was to swing it around. Oumuamuo will resume a straight path once more, (albeit in a different direction), and will never come back towards the sun again.
I use an 11" reflector (Celestron CPC 1100) and a 3" refractor, (Sky-Watcher ST80) mounted on an equatorial wedge, housed in a 2.2m Pulsar observatory. I use a ZWO ASI 120MM, ZWO ASI1600MC and Canon 1300D for imaging.
Aratus

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Joined: Tue Jan 12, 2016 2:17 pm
Location: East Lincolnshire

### Re: Oumuamuo

Here's a screen grab from iPlayer showing the difference between the closed orbit of a comet (dotted) and the open orbit of 'Oumuamua (solid).
Scopes: Meade 8" SCT, Skywatcher 127mm Mak, Raffle winner of SW ST80
For imaging: Pentax K5, Asda webcam, Star Adventurer (new toy)
For companionship: Mid Cheshire Astronomical Group.
(Not a moderator)
Gfamily2

Posts: 516
Joined: Thu Jun 25, 2015 10:38 pm

### Re: Oumuamuo

Thanks guys
Dougy broon

Posts: 2
Joined: Mon Feb 12, 2018 8:25 am