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2021 RG19
#30
Phil, it gets crazy when working with the new finds. I go to https://minorplanetcenter.net/db_search and put in the object to see what is listed for the arc number of observations and then look at the uncertainty. TZ is 8 so that would be a stretch to find no matter what. It has a one day arc and only 14 observations!! I like to use the elements from the MPC but often find that the JPL elements are more up to date. That's their job, to keep track of dangerous rocks from space. Use CNEOS minimum distance table as a guide only. Just a tool to begin a hunt.

When I do hunting for 2021 TZ, I find close approach to my house (always use that and with Horizons also), to be September 21 2021, 11:22:11TDB at 58LD mag 20.5 using JPL elements epoch Oct 3, 2021. Positions agree with those at Horizons. And it's in daylight or moon interference. Closest approach on the Horizons ephem page is found easily by looking for the deldot closest to zero.

So looking at 2015 TQ21. On the CNEOS page the uncertainty is 5days 23hours 8minutes!! Close approach data 2021-Oct-07 13:37 ± 5_23:08. So good luck hunting that lost rock.

Again, looking on the Minor Planet Search page the uncertainty is 7 but at least there are 21 observations over 4 days.

So I find it just takes a lot of research b4 plugging things into ST4. And then you'll need elements (JPL) within one day of your plotting and searching. Let horizons make you a set near when you want to observe the field.

Look at 1998 SD9 on the MPC search page. It has 115 observations over a 3668 day arc. Uncertainty zero!

It appears we missed, due to late find, 2021 TX. A very close pass small rock that was about 1 mag out of reach. On Oct 1 16:27CDT (daylight), it came whipping by my yard, moving 1.5°/min. As dark arrived, it quickly dropped below my horizon then back up but slammed on the brakes down to 86"/min and dropping another 2 mags.

Also missed 2021 TV1 close pass.
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Messages In This Thread
2021 RG19 - by PMSchu - 2021-09-27, 04:20 PM
RE: 2021 RG19 - by razvan - 2021-09-27, 07:54 PM
RE: 2021 RG19 - by PMSchu - 2021-09-27, 10:30 PM
RE: 2021 RG19 - by razvan - 2021-09-28, 12:09 AM
RE: 2021 RG19 - by PMSchu - 2021-09-28, 12:53 AM
RE: 2021 RG19 - by razvan - 2021-09-28, 03:54 AM
RE: 2021 RG19 - by PMSchu - 2021-09-28, 03:33 PM
RE: 2021 RG19 - by razvan - 2021-09-28, 09:32 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-09-28, 10:23 PM
RE: 2021 RG19 - by razvan - 2021-09-29, 04:16 AM
RE: 2021 RG19 - by bigmasterdrago - 2021-09-29, 11:51 AM
RE: 2021 RG19 - by PMSchu - 2021-09-29, 03:50 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-09-30, 03:05 AM
RE: 2021 RG19 - by PMSchu - 2021-09-30, 04:24 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-09-30, 05:01 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-09-30, 09:55 PM
RE: 2021 RG19 - by razvan - 2021-10-02, 11:19 PM
RE: 2021 RG19 - by PMSchu - 2021-10-03, 12:03 AM
RE: 2021 RG19 - by razvan - 2021-10-03, 02:04 AM
RE: 2021 RG19 - by bigmasterdrago - 2021-10-03, 02:38 PM
RE: 2021 RG19 - by PMSchu - 2021-10-03, 04:33 PM
RE: 2021 RG19 - by razvan - 2021-10-04, 12:18 AM
RE: 2021 RG19 - by bigmasterdrago - 2021-10-03, 09:44 PM
RE: 2021 RG19 - by PMSchu - 2021-10-04, 12:53 AM
RE: 2021 RG19 - by razvan - 2021-10-04, 02:37 AM
RE: 2021 RG19 - by bigmasterdrago - 2021-10-04, 04:40 PM
RE: 2021 RG19 - by PMSchu - 2021-10-04, 04:52 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-10-04, 11:18 PM
RE: 2021 RG19 - by PMSchu - 2021-10-05, 03:26 PM
RE: 2021 RG19 - by bigmasterdrago - 2021-10-06, 03:51 AM

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