2010 CA261 Close approach

[PMSchu]

All,

Here's the latest on 2010 CA261. I checked both the MPC & JPL HORIZONS websites for this object today & both return 'NO MATCH'. I downloaded a set of elements for this object on Aug 14 from HORIZONS. My ST$v still has the elements that I downloaded from MPC on Aug 11 that predicted the MP would be ~10 mag. This is very odd. The object seems to have been removed from the DB.

I was never able to observe it, so something was wrong with the elements or something. Very strange. The object that I'd fllagged in ST4v as 2010 CA261 last week, now shows up in my OL as (410777) 2009 FD. 

BMD, has the same thing happened to your Observing List?

Phil S.

[theskyhound]

Here is what the MPC has 2010 CA261:

https://www.minorplanetcenter.net/db_sea...2010+CA261

It may be that there was a provisional match to a newly discovered object, or something along those lines. Given that there was nor orbit even in 2010, I think this one is lost.

[PMSchu]

LOST is a reasonable assumption, but it wasn't listed that way last week or mid-August. They just changed things recently.

How did you get the MPC to return even this much? When I put '2010 CA261' in the search box, it returned 'NO MATCH'.

Phil S.

[theskyhound]

LOST is a reasonable assumption, but it wasn't listed that way last week or mid-August. They just changed things recently.

How did you get the MPC to return even this much? When I put '2010 CA261' in the search box, it returned 'NO MATCH'.

Phil S.

Google.

[PMSchu]

That's just not right!

Phil S.

[bigmasterdrago]

This rock caught my attention just now as I noticed on Gideon's page a close approach on August 11th at 0.023AU. I grabbed the elements from the MPC search page - https://minorplanetcenter.net/db_search/...2010+CA261 which now has it listed as a main belt rock with an uncertainty of 2! Running the numbers indicates closest (1.3AU) last Sept 13 at mag 21.3, mag 23 at Gideon's August 11, 2022 (should be 2.9AU, not 0.023AU), and then again on Feb. 12, 2023 at mag 21.7 and 1.5AU. No wonder we were unable to find it looking for a 10th mag rock. The ephemeris using the MPC elements agrees with that generated at Horizons. I think Gideon is using elements from last year when the uncertainty was high. The rocks correct provisional designation is 2009 WR192.

[PMSchu]

Thanks, BMD. That explains a lot. Now a search for 2010 CA261 at the MPC finds the object, unlike last year when the search returned 'No Match'. They must have decided that this object corresponded to 2009 WR192 & assigned that designation. As a main belt object it certainly wasn't making a close approach last summer.

2010 CA261 isn't in my MP DB containing 1.2E6 MPs, but 2009 WR192 is.

Phil S.