March close flyby of NEO asteroid 2006 VV2

[Zathris]

March close flyby of NEO asteroid 2006 VV2

Discovered on November 11, 2006 by LINEAR, asteroid 2006 VV2 will approach within 0.023AU or (8.8 Lunar distances) on March 31, 2007. This 1.5km object is currently at Magnitude 16 but will reach 10th magnitude at near approach.

Presently (4/15/07) in Cepheus, 2006 VV2 has an angular motion of only 0.025 arc/sec per second. By March 26th when 2006 VV2 makes it's closest approach to Polaris it will still only have an angular speed of around 0.027 arc/sec. Just two days later however, when 2006 VV2 passes just 11 arc minutes from M81 (around 7:30pm) it's angular speed will be over 0.5 arc/sec per second.

At nearest encounter the asteroid will be in the constellation of Leo. Current predictions place greatest angular speed around 1:00am March 31st. At that time it will be placed in a very favorable position in the sky (Aprox. 51 degrees above the western horizon, well here in New Mexico). By then 2006 VV2 will be traveling a blazing 1 arc/sec per second (one degree per hour). Unfortunately the Moon at 95% will only be twenty one degrees away.

Two days later it will pass into Hydra and slow to just over 0.5 arc/sec. 2006 VV2 will continue to slow till it enters Centaurus where it will fade beyond the limits of amateur equipment.

If you plan to observe or image this asteroid especially in the last few days before near approach you should check for current positions on line as the Earth’s gravitational field may cause the asteroid to change course or speed slightly.

Near Earth Objects – Dynamic Site
http://newton.dm.unipi.it/cgi-bin/neodys/neoibo?objects:2006VV2;obspred

Zathris....

[Gary Beal]

Interesting Zathris,
can one image this as it moves? Any suggestions?
Gary

[Zathris]

Yes you can, in fact it should be fairly easy to image. I plan (weather permitting) to attempt to image it as it passes M81 on the night of the 28th. People on the East cost will get a better chance than I however as it will pass M82 before it is dark here in NM. I will be using an Orion ED80 and ST8-XE to try and capture the event. By that time the asteroid will be moving over 0.5 arc/sec per second. Since I will bin the camera 2x2 I will have about 6.18 arc/sec per pixel. That means that I should get about 12 seconds exposure per pixel. That should be long enough to capture it even at the estimated brightness of 11.8. Even though each pixel will only receive 12 seconds of exposure, I will do one minute subs to show a slight streaking. I will shoot one minute subs till 2006 VV2 exits the FOV, then increase to ten minute subs to better enhance M81 & m82.

When processing I will combine the longer exposures normally to create a background image. Then one at a time layer a frame of the one minute exposures using the Lighten blending method. This will add the asteroid while leaving the rest of the image as is. Save that image as a frame, remove the one minute layer, add the next, save that as a frame, etc. I will then take the frames and combine them as an animated gif.

Well that is the plan anyway. Other examples are just take long subs of M82 as you normally would, sum the images and you will have a streak passing the galaxy. If you use a separate guide scope, you could guide on the asteroid and get a bright image of it (as long as you care to expose) and have the stars trail across your FOV. And if you don’t care about getting it passing m81 &m82 you can do this any night you like and watch it track across the background stars.

The thing to keep in mind I think is that unless you track on the asteroid itself then you should take into account the time it will spend on each pixel before moving to another. That will be the longest effective exposure time you can get. For example if I tried to image it with an 8" SCT even at f/6.3 with a Canon 400XT, it would have less than 1 arc/sec per pixel. That means less than two seconds of exposure per pixel. That might be beyond the sensitivity of this camera. But even a modest camera like the Meade DSI Pro and a 300mm lens will give you about nine second exposures, just keep the asteroids brightness and your image scale in mind.

A flat image should not be to difficult with the proper image scale, but since there are so few astronomical events that show movement on a human scale I will try to capture an animation as I did back in Nov. for the Mercury Transit.
http://www.budgetastro.com/web/mercury-transit.html

Zathris....