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Asteroid 2012 DA14 Workup For Imaging

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#1 mmalik

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Posted 09 February 2013 - 07:44 AM

Asteroid 2012 DA14 workup for imaging on Feb 15, 2013:

Few questions to get the discussion started:

1. What is the proper way to image an asteroid (especially this one), i.e., what's the proper way to guide? [For the night of Feb 15, I think it is roughly moving at sidereal rate? (see red pics below...)]

2. What are appropriate exposure and ISO settings for this object?

3. How images should be combined/processed for such an object?

Thx

Note: SkySafari Pro... seems to be the invaluable mount tool to locate this object effortlessly.


3-hour time ticks, times in GMT below:
Posted Image


09:00 PM Central Time (US) Feb 15, 2013 below:
Note: Cross hairs signifies the asteroid 2012 DA14.

Posted Image

#2 Driven1

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Posted 09 February 2013 - 09:58 AM

I haven't done anything like this myself but I've seen stuff here on cloudynights where people have done it. I believe they guide using PHD with a good guidescope and guide camera using the object itself as the guide point for tracking. Could be a toughie. My understanding is that it won't be too bright. I would expect processing to be pretty much the same as any other. As far as ISO's, don't know on that. Maybe the NEO forum?

#3 ewave

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Posted 09 February 2013 - 11:48 AM

When discussing stacking, another thing to keep in mind is to find out if the object itself is rotating about its axis (especially if this is not a fixed axis?) and then find out its period of rotation. Then as if that wasn't bad enough, it would probably be best to shoot the object within the same evening as its angle with repect to your location may differ as this object's position changes quickly in the sky from night to night. Of course if the object is too dim, this will require longer exposure times, which could hurt stacking results. Does anyone know this object's rotation properties?

mmalik - does sky safari integrate with your mount for tracking of such objects like these or comets?

#4 Dan Crowson

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Posted 09 February 2013 - 03:31 PM

mamalik,

I've been looking at imaging this one as well if I have clear skies from my house near Saint Louis, Missouri. We can only see it several hours after the closest approach so it will be "moving" slower at that point. The issue you're going to run into is that it will be moving very fast. According to TheSky, and using some calculations, with my 1368 f/9 AT6RC and a SBIG ST-8300M, the longest exposure I can take at 1x1 (before I would get streaking) would be about 1 second. Binning 3x3, I could probably go up to around 3 seconds. To figure this out, I do this:

([arcsec/pixel ratio]/([max movement - ra or dec] * 60)) * 60

I'm thinking I'll probably take the 3 second 3x3 exposures and end up making some kind of animation. Unfortunately, it will be vary grainy because of the lack of exposure times.

Dan

#5 Rick J

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Posted 09 February 2013 - 04:18 PM

It's motion at closest approach is nearly due north and much faster than sidereal rate of 15" per second of time. By evening in the US it will have slowed to about 6" per second of time, still a challenge unless your mount will track satellites. But you will need very current elements as those will change greatly as it passes by. Also parallax will be severe this close. Even your elevation will need be accounted for. So far the most current elements from JPL and the Minor Planet Center don't agree all that well, another problem. This is going to be one difficult object even with my ability to have the mount track the asteroid based on its orbital elements. My forecast is for clouds :( however. That's been the norm for weeks now.

Rick

#6 mmalik

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Posted 09 February 2013 - 07:44 PM

does sky safari integrate with your mount for tracking of such objects like these or comets?


No, it mainly helps navigate, point and align without having to punch in the coordinates; tracking/guiding being mount-side functions as usual. Thx

#7 Sean13

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Posted 09 February 2013 - 10:00 PM

I'm going to be attempting to track a nearby star and capture the motion of it as it passes thru the fov, since I know I won't be able to track it.

#8 mmalik

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Posted 10 February 2013 - 02:43 AM

I'm going to be attempting to track a nearby star and capture the motion of it as it passes thru the fov, since I know I won't be able to track it.


I think you should be able to track it (on a star) if your exposures are short and your FOV is wide; I think it should NOT pass through a wide field that quickly. Overall, asteroid will be moving in somewhat circular motion around the north star and alongside the (EDIT:) little dipper in the usual anti-clockwise fashion [Note: This applies to the night of Feb 15, 2013 in Central Time zone (US); see above.]

#9 mmalik

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Posted 10 February 2013 - 08:39 AM

I have updated my first post to show the latest per SkySafari Pro which seems to have changed since my original post. Thx

#10 mmalik

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Posted 10 February 2013 - 09:25 AM

9-hour motion vector (approx.) for the night of Feb 15:

9:00 PM - 6:00 AM Central Time (US) Feb 15, 2013
Posted Image

#11 mmalik

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Posted 10 February 2013 - 10:53 AM

Some more info...

Asteroid 2012 DA14 will make closest approach to Earth on February 15, 2013 at about 1:24 PM CST (19:24 UTC), when it will be at a distance of about 27,700 kilometers (17,200 miles) above the Earth's surface and will pass inside the ring of geosynchronous weather and communications satellites.

It appears folks in Asia and Eastern EU will have the opportunity to see/image the closest approach at magnitude 7.5; will probably still be tricky to image given the faster movement across the night sky.

Not so thrilling part... by the time continental US will have the opportunity to see/image it would have faded to 11th magnitude, although apparent motion across the night sky would have slowed down a bit. (see pics above)

Looks like '2012 DA14' is going to hang between little dipper and Cepheus till the end of March or so after this encounter, but will much increase in magnitude.


Note: 2012 DA14's orbital period around the Sun has been about 368 days which will be reduced to about 317 days with this encounter; hence future approaches will be follow a different pattern.

#12 cn register 5

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Posted 10 February 2013 - 01:34 PM

From the UK DA14 rises in the early evening and passes just to the East of Denebola, then up and through the tail of the Plough before ending up near the pole. I think we get the maximum brightness - but not the closest approach.

My plan is to retreat to the pub because it's cloudy.

Chris

#13 mmalik

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Posted 12 February 2013 - 08:04 AM

1-hour time pics below:
Note: Times in Central Time (US) [UTC-06:00]

Closest approach occurs at about 1:24 PM Central Time (US) Feb 15, 2013, the fourth pic below.

10:24 AM Central Time (US) Feb 15
Posted Image

11:24 AM Central Time (US) Feb 15
Posted Image

12:24 PM Central Time (US) Feb 15
Posted Image

1:24 PM Central Time (US) Feb 15
*** CLOSEST APPROACH ***
Posted Image

2:24 PM Central Time (US) Feb 15
Posted Image

3:24 PM Central Time (US) Feb 15
Posted Image

4:24 PM Central Time (US) Feb 15
Posted Image

5:24 PM Central Time (US) Feb 15
Posted Image

6:24 PM Central Time (US) Feb 15
Posted Image

7:24 PM Central Time (US) Feb 15
Posted Image

8:24 PM Central Time (US) Feb 15
http://farm9.static....f0db3f9ef_z.jpg

9:24 PM Central Time (US) Feb 15
http://farm9.static....2623d47ee_z.jpg

10:24 PM Central Time (US) Feb 15
http://farm9.static....93fc3fa98_z.jpg

11:24 PM Central Time (US) Feb 15
http://farm9.static....9e5576763_z.jpg

12:24 AM Central Time (US) Feb 16
http://farm9.static....799b9bc26_z.jpg

1:24 AM Central Time (US) Feb 16
http://farm9.static....d0cac80e2_z.jpg

2:24 AM Central Time (US) Feb 16
http://farm9.static....48e3728d8_z.jpg

3:24 AM Central Time (US) Feb 16
http://farm9.static....4cf1661e3_z.jpg

#14 cn register 5

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Posted 12 February 2013 - 04:52 PM

Are these pictures straight from a planetarium program?

I ask because the times look strange and I've heard that planetarium programs don't allow for the Earth's gravity affecting the orbit. I found that the positions in CdC derived from MPC orbit elements were about two hours different in time to what the JPL/Horizons ephemeris gave.

Chris

#15 mmalik

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Posted 13 February 2013 - 06:33 AM

Are these pictures straight from a planetarium program?


Yes, the path was charted in SkySafari Pro; it seems comparable to most of the passage diagrams I have seen. Thx

#16 pfile

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Posted 13 February 2013 - 01:02 PM

there was an update to skysafari pro this morning which is supposed to take into account the gravitational effects on asteroids. i don't know how up-to-date the ephermeris is for 2012 DA14 but the orbit does seem a little different than the screenshots above.

#17 mmalik

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Posted 13 February 2013 - 08:19 PM

there was an update to skysafari pro this morning which is supposed to take into account the gravitational effects on asteroids. i don't know how up-to-date the ephermeris is for 2012 DA14 but the orbit does seem a little different than the screenshots above.


I have updated the pics above with the latest. Thx

#18 mmalik

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Posted 14 February 2013 - 07:16 PM

Astroid 2012 DA14 path on Feb 15:
Image courtesy of David Dickinson/Edit: M Malik
More info here...

Attached Files



#19 mmalik

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Posted 15 February 2013 - 06:18 AM

Useful links...

http://www.ustream.tv/nasahdtv
http://www.ustream.tv/nasajpl2
http://www.nasa.gov/multimedia/nasatv

NASA Television will provide commentary starting at 1PM CST (19:00 UTC) on Friday, Feb. 15.

#20 mmalik

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Posted 15 February 2013 - 01:08 PM

Watch Asteroid 2012 DA14 live here..., being telecasted now...


On a side note, computer simulation here....

#21 pfile

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Posted 16 February 2013 - 01:16 AM

i managed to get some images, first tracked at sidereal rate, 10s each with the asteroid crossing a roughly 0.8 degree field. then i did 5s each. then i tried to program my mount to track the comet, and i was partially successful. the rates were not exactly right, but close. i'm going to try to make some videos.

#22 mmalik

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Posted 16 February 2013 - 03:19 AM

Look forward to your images/video; I couldn't image mainly due to extremely cold temps. Thx

#23 pfile

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Posted 16 February 2013 - 12:51 PM

i have the worst cold so i'm having a hard time doing any work...

#24 Dan Crowson

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Posted 16 February 2013 - 01:57 PM

Here's what I was able to get from around St. Louis, Missouri. It was somewhat cloudy and I'm in a red light pollution zone so there's not much to it.

Flickr Link

Details on the page.

Dan

#25 pfile

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Posted 16 February 2013 - 02:36 PM

that looks great, dan. maybe i should have shot bin 3x3. i did 2x2.






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