Asteroid 2012 DA14 Workup For Imaging
Posted 09 February 2013 - 07:44 AM
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?
Note: SkySafari Pro... seems to be the invaluable mount tool to locate this object effortlessly.
3-hour time ticks, times in GMT below:
09:00 PM Central Time (US) Feb 15, 2013 below:
Note: Cross hairs signifies the asteroid 2012 DA14.
Posted 09 February 2013 - 09:58 AM
Posted 09 February 2013 - 11:48 AM
mmalik - does sky safari integrate with your mount for tracking of such objects like these or comets?
Posted 09 February 2013 - 03:31 PM
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.
Posted 09 February 2013 - 04:18 PM
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
Posted 09 February 2013 - 10:00 PM
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.]
Posted 10 February 2013 - 08:39 AM
Posted 10 February 2013 - 09:25 AM
9:00 PM - 6:00 AM Central Time (US) Feb 15, 2013
Posted 10 February 2013 - 10:53 AM
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.
Posted 10 February 2013 - 01:34 PM
My plan is to retreat to the pub because it's cloudy.
Posted 12 February 2013 - 08:04 AM
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
11:24 AM Central Time (US) Feb 15
12:24 PM Central Time (US) Feb 15
1:24 PM Central Time (US) Feb 15
*** CLOSEST APPROACH ***
2:24 PM Central Time (US) Feb 15
3:24 PM Central Time (US) Feb 15
4:24 PM Central Time (US) Feb 15
5:24 PM Central Time (US) Feb 15
6:24 PM Central Time (US) Feb 15
7:24 PM Central Time (US) Feb 15
8:24 PM Central Time (US) Feb 15
9:24 PM Central Time (US) Feb 15
10:24 PM Central Time (US) Feb 15
11:24 PM Central Time (US) Feb 15
12:24 AM Central Time (US) Feb 16
1:24 AM Central Time (US) Feb 16
2:24 AM Central Time (US) Feb 16
3:24 AM Central Time (US) Feb 16
Posted 12 February 2013 - 04:52 PM
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.
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
Posted 13 February 2013 - 01:02 PM
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
Posted 16 February 2013 - 01:16 AM
Posted 16 February 2013 - 03:19 AM
Posted 16 February 2013 - 12:51 PM
Posted 16 February 2013 - 02:36 PM