Looking at the July-Sept Minor Planet Observer, I see that 3833 appears to be near opposition on August 26 and that it is classified as a Mars-orbit-crossing asteroid. I am on my Linux box right now and cannot bring up the JPL Orbit Diagram applet. How far will 3833 be in A.U. on August 26? Thanks - Kurt --- On Sat, 7/31/10, Canopus56 <canopus56@yahoo.com> wrote:

From: Canopus56 <canopus56@yahoo.com> Subject: Re: [Utah-astronomy] Parallax experiment with (3833) Calingasta To: "Utah Astronomy List Serv" <utah-astronomy@mailman.xmission.com> Date: Saturday, July 31, 2010, 5:55 PM Patrick, 

Thanks for the notes.  The method I outlined only applies to targets at opposition - which for asteroids can be determined in real time using Warner's MPO Canopus Lightcurve group. 

http://www.minorplanetobserver.com/Misc/EphemerisGenerator.htm

But I forgot to ask the obvious first question: Is the asteroid in the photo at opposition?  If it was not, then the method discussed upthread is not directly applicable.

I have not run the specific  computation to find the distance limit for a diurnal parallax measurement.  It probably would reach the inner asteroid belt using amateur equipment, but not 1 A.U.

Warner's Asteroid Ephemeris Generator lists the following asteroid as coming to opposition on July 30 - 1004 Belopolskya, mag 14.4, but it is at a distance 3.8 A.U.

- Clear Skies - Kurt