Spotting 2005 YU55: Instructions & Speed Info

[DaveC426913]

Can anyone direct me to some instructions that will tell me how I might be able to spot it? I know it may be difficult and may require a scope of at least 6", but we'll see.

I keep hearing that it will be moving "very" fast. How fast? Fast enough to see movement against the background?

 

[davenn]

hey Dave
try this site it has the asteroid path on a starmap

http://cuyastro.org/

Im envious We don't even get a chance to see it in the sthrn hemisphere

Dave

 

[DaveC426913]

try this site it has the asteroid path on a starmap

Awesome. Thanks.

Wow! Those ticks are marking off hours.

 

[davenn]

I don't know if you are in a dark site or can get to a dark site near home. ?
It would be interesting to get a camera on a tripod and do a really long exposure ...aperture wide open eg F2 - F5 the best you can do and exposures of up to 30 minutes.
You will get long star trails, but you mite, just mite see a faint path of the asteroid cutting across the trails. It would really be worth a try :)

cheers
Dave

PS ... 30mins was with good ol' film camera would be worth trying say 10 - 15 mins with a DSLR

 

[Drakkith]

Hrmm. Maybe I can get a few shots of it in my scope. I'll have to take everything into work, or miss the closest approach.

 

[turbo]

Good luck, Drakkith. Hope to see shots.

 

[turbo]

BTW, Curt Renz's calculations show that the asteroid will span the apparent width of the Moon in about 3.5 minutes, at closest approach, so if you have a decent-sized 'scope, you'd have to be pretty fancy to capture that asteroid as a "spot" instead of a streak.

 

[Drakkith]

BTW, Curt Renz's calculations show that the asteroid will span the apparent width of the Moon in about 3.5 minutes, at closest approach, so if you have a decent-sized 'scope, you'd have to be pretty fancy to capture that asteroid as a "spot" instead of a streak.

My plan is to point to the location ahead of time and just start taking exposures when it comes time. Trying to actually track it with the scope is useless unless I can manually do it. Which is unlikely.

 

[DaveC426913]

My plan is to point to the location ahead of time and just start taking exposures when it comes time. Trying to actually track it with the scope is useless unless I can manually do it. Which is unlikely.

You think it's moving that fast?


Also, closest approach is 11:30 UT, isn't that, like, 5AM ET?

 

[Drakkith]

You think it's moving that fast?Also, closest approach is 11:30 UT, isn't that, like, 5AM ET?

Hrmm. I didn't realize it was UT. That makes it 1800, aka 6 PM my time.

 

[DaveC426913]

Hrmm. I didn't realize it was UT. That makes it 1800, aka 6 PM my time.

Barely past dusk...

What part of the sky is it in at that time? If anywhere other than East, we might be out of luck anyway.

 

[DaveC426913]

BTW, Curt Renz's calculations show that the asteroid will span the apparent width of the Moon in about 3.5 minutes, at closest approach, so if you have a decent-sized 'scope, you'd have to be pretty fancy to capture that asteroid as a "spot" instead of a streak.

Forget photos. I want video! I want to see an object noticeably moving across the starscape in real time. That would be awesome!

 

[Drakkith]

Barely past dusk...

What part of the sky is it in at that time? If anywhere other than East, we might be out of luck anyway.

It will be in the East, passing right through Pegasus at the time. We have thunderstorms raining down on us now, so I wouldn't be able to see it today no matter what lol.

 

[mkarger]

Wait so if those ticks mark hours, that means I should be able to see it for quite a while, right?

I have an 8 inch Dobsonian and I live in Phoenix. I missed the closest pass but I assume it will still be visible at later hours. I won't be around my telescope until about 8 PM Arizona time (7 hours off UTC).

 

[mkarger]

Also, I have the 2010 version of Starry Night and apparently 2005 YU55 is not in the database.

 

[mkarger]

Nevermind I just had to run update.

Hooray, it will be visible well after I get home.

 

[Drakkith]

Nevermind I just had to run update.

Hooray, it will be visible well after I get home.

Yeah I'm hoping it will clear up for me tonight so I can catch a view too.

 

[Oldfart]

I just saw a NASA radar image of it, how come the bottom half of the astroid is in shadow like an optical image?

 

[mkarger]

I just saw a NASA radar image of it, how come the bottom half of the astroid is in shadow like an optical image?

Most likely due to the relative wavelengths they are observing. While all objects emit at least trace levels of radio-waves, it's hard to detect. Most radio-waves are reflected off an object. So if part of the asteroid is in a shadow,not directly in the path of the suns light, there can be a shadow in other sections of the light spectrum.

 

[DaveC426913]

Most likely due to the relative wavelengths they are observing. While all objects emit at least trace levels of radio-waves, it's hard to detect. Most radio-waves are reflected off an object. So if part of the asteroid is in a shadow,not directly in the path of the suns light, there can be a shadow in other sections of the light spectrum.

Or more simply, since the asteroid doesn't emit any radiation on its own, all radiation - including radio - will be as reflected light from the sun.

 

[Drakkith]

Or more simply, since the asteroid doesn't emit any radiation on its own, all radiation - including radio - will be as reflected light from the sun.

What do you mean? We use radar to track and map objects within the solar system. I assumed they did the same thing here.

 

[mkarger]

Or more simply, since the asteroid doesn't emit any radiation on its own, all radiation - including radio - will be as reflected light from the sun.

IIRC, all bodies emit radiant energy.

 

[DaveC426913]

Right. Of course. I don't know what I was thinking. A body in full shadow still emits IR.

 

[2milehi]

Good info

http://www.dailymail.co.uk/sciencet...t-How-track-close-encounter-Earth-today.html"

 

[mkarger]

Well that was a depressing half hour. Turns out it's hard to find an asteroid with a manual telescope.

I gave up after my opposing eye started twitching.

 

[turbo]

At mag ~11 or so, you'd need a decent finder chart and an OK telescope to even pick it out. At closest approach, the asteroid would take 3.5 minutes to span the apparent diameter of the moon, so even though it is moving right along, it wouldn't be real obvious with a casual glance - you'd need to watch it for a while.

 

[mkarger]

At mag ~11 or so, you'd need a decent finder chart and an OK telescope to even pick it out. At closest approach, the asteroid would take 3.5 minutes to span the apparent diameter of the moon, so even though it is moving right along, it wouldn't be real obvious with a casual glance - you'd need to watch it for a while.

I have an 8 inch dobsonian. I pinned the relative area of the object down with Starry Night and spent my time panning and stopping to observe potential candidates. I couldn't find it. This might partly be because I have no idea what it's relative size would look like through my scope.

Plus, the light pollution is terrible in Phoenix. I hate this place.

 

[davenn]

Right. Of course. I don't know what I was thinking. A body in full shadow still emits IR.

NASA's radar images don't require the object to emit any sort of radiation radio or IR

NASA and others just bounce their own radio signal off the object
thats why its called a RADAR image :)

cheers
Dave

 

[davenn]

sooooooooooooooo guys ?

did anyone of our awesome PF clan get to see it ?
did anyone try any long exposures from a dark site ?

Dave

 

[Drakkith]

sooooooooooooooo guys ?

did anyone of our awesome PF clan get to see it ?
did anyone try any long exposures from a dark site ?

Dave

Not I. Rained on me and I am too far west.

 

[Oldfart]

I just saw a NASA radar image of it, how come the bottom half of the astroid is in shadow like an optical image?

Now that some of the dust has settled, I'll try this question again...

 

[DarioC]

OF,
On the radar image, two possibilities occur to me. The first is that the object is shaped so it tapers away from the "front" at the bottom and would not reflect the RF back very well.

Another possibility is that they just caught the asteroid with the outer edge of the coverage area of the transmit antenna.

Could be a combination of the two. Could be something completely different.
DC

 

[AlephZero]

NASA and others just bounce their own radio signal off the object
thats why its called a RADAR image :)

I haven't done any research on what shape this thing is, but I'll bet anybody $1,000 it's not a smooth sphere. Any apparent "shadow" effects will be variations in the reflectivity of different parts of the surface.

 

[Oldfart]

I haven't done any research on what shape this thing is, but I'll bet anybody $1,000 it's not a smooth sphere. Any apparent "shadow" effects will be variations in the reflectivity of different parts of the surface.

Well, it's a little lumpy, but still rather spherical. There's a radar video from Goldstone, it shows YU55 rotating about an axis pretty much parallel to our line of sight, and the bottom of the image stays dark regardless of the changing view.

Just give my $1000 to charity, thanks...

 

[2milehi]

No chance for me to try and see it. There were high, thin clouds that were being lit up by the full moon. The only "star" visible in the area of interest was Jupiter.