Track and Stack

Align the images on the asteroid and let the stars trail. 

Sets of Images to Track and Stack:

If you want to try and track and stack single asteroid images and you would like to be able to do this yourself from the 30-80 images that Bob Holmes takes for each target, you can get the image sets at this link.  Otherwise, you can just work from the IASC site with the stacked sets provided. 

Speed and PA of Asteroids  

    Astrometrica has the Speed and PA for known asteroids.  When you stack the images you can click on the ... in asteroid field and then write in the name of the asteroid in the form and hit the search icon.  If the target is in the box, choose it and hit return. The Speed and PA automatically pops into the form and you can track the stacks on the asteroid.  You can also restack the images at any time to go with different asteroids that might be in the field.  Right click on one your stacks to see the re-stack option. If the target is unknown to Astrometrica then to to the MPC site. 

1.) Go to the NEOCP at 

and see if your object is listed, if so, check the box next to it and 

click on "get ephemerides" - 

make sure you use the speed value in arcseconds per minute (i.e."/min)

2.) If the object is not listed go to and see if the

object has a provisional designation. Some objects may not be confirmed (they were

either lost or could have been a false signature in observer's data). If the object

has a provisional designation, use it to let Astrometrica retrieve the motion speed

and PA automatically.

3.  However, if the MPEC for the object in question has been released only recently (ie

within the last 24 hrs) or you haven't updated the MPCORB.dat recently, Astrometrica

won't be able to automatically calculate the speed and PA. In that case you'll need

to use MPC's Ephemeris Service at - enter the provisional

designation and make sure you set the following options:

Ephemeris start date - to the date when the object was observed

Number of dates to output: 12

Ephemeris interval: 1

Ephemeris units: hours

Display motions as:  "/min

If the object is moving very fast, i.e. > 10"/min or it's speed and PA are changing

rapidly, you may need to use:

Number of dates to output: 24

Ephemeris interval: 30

Ephemeris units: minutes

or similar to find the motion speed / PA for the time at which your images were taken.

Then find the motion speed and PA for the date & time at which the observations of

the object were made.

P.S.  You should update your MPCORB.dat for Astrometrica on regular basis - I use

this mirror that works really well

Here is more of an illustration of how to use the Ephemeris Service Page.

    The Minor Planet Center (MPC) has a page that will give you the Speed and PA and the expected positions of asteroids. Complete Form.  

Example: images that go with IASC 2-24-2010 sets are on the Yerkes site zipped into one big file. You will have the original single images that you can divide into thirds and stack in Astrometrica with the speed and PA below.  Also see the link to find out the speed and PA for any asteroid now or in the past or future. 

ARI 24 inch telescope Feb 24, 2010 speed and position angle data for the night these sets were taken.

2010 CD55    Speed 12.30      PA 235.0

2010 DU1     Speed 108.10     PA 264.8

2009 XR2     Speed .76        PA 80.1

2010 BH2     Speed 1.44       PA 24.3

But in the future, for speed and PA on different dates, use this site.  Put in the target for any day into the future or past to get the speed and PA.  Here is a screenshot of how to setup this page.  


Another cool page is 

NEO Earth Close Approaches