2022-01-19, 03:51 PM
(This post was last modified: 2022-01-19, 04:20 PM by bigmasterdrago.)
Phil, you had asked about the differences in position with elements at the beginning of this thread and more recently. I took a look and found nothing significant. I think because we are using the same elements from the MPC with the same epoch, in theory they should look the same. But a closer look shows that due to the adjustment caused by the gravity influence when getting near us, software can make a difference. Or in the case of ST4, the need to massage the inputs. I made a table of positions and all use the MPC except one that can only use Lowell. It was very educational to see the 3 positions in ST4 given a bit of correct input. Three choices - MPC, MPC NEA Daily or Osculating Elements created by Horizons. Lesson is to always use Osculating for NEAs. Although the MPC NEA Daily can be a much faster exercise and nearly as accurate.
All errors referenced Horizons from my location:
Date_CST _HR:MN R.A. DEC Azi Elev APmag Software Error
2022-Jan-18 19:00 01 39 14.10 +08 21 03.6 211.08 64.96 10.395 (Horizons) 0.0"
01 39 13.7 +08 21 07.1 212.3 65.16 9.52 (AstroGrav) 6.6"
01 39 13.8 +08 21 09 211.08 64.28 10.3 (ST4 Osc Els) 8.1"
01 39 13.5 +08 21 13 211.08 64.28 10.4 (ST4 MPCNEADy) 14.0"
01 39 23.1 +08 19 53 211.5 64.7 10.4 (MegaStar 5) 2.5'
01 39 27.4 +08 17 30 210.9 65.25 10.4 (SkyTools 4) 4.9'
I was clouded out last night, being only able to spot the fuzzy moon and a couple of bright stars. Strangely, my buddy 25 miles SSW had partial clearing and was able to shoot a series of 30 second images. I'll send a copy when I get it.
All errors referenced Horizons from my location:
Date_CST _HR:MN R.A. DEC Azi Elev APmag Software Error
2022-Jan-18 19:00 01 39 14.10 +08 21 03.6 211.08 64.96 10.395 (Horizons) 0.0"
01 39 13.7 +08 21 07.1 212.3 65.16 9.52 (AstroGrav) 6.6"
01 39 13.8 +08 21 09 211.08 64.28 10.3 (ST4 Osc Els) 8.1"
01 39 13.5 +08 21 13 211.08 64.28 10.4 (ST4 MPCNEADy) 14.0"
01 39 23.1 +08 19 53 211.5 64.7 10.4 (MegaStar 5) 2.5'
01 39 27.4 +08 17 30 210.9 65.25 10.4 (SkyTools 4) 4.9'
I was clouded out last night, being only able to spot the fuzzy moon and a couple of bright stars. Strangely, my buddy 25 miles SSW had partial clearing and was able to shoot a series of 30 second images. I'll send a copy when I get it.