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Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April...
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![Page 1: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/1.jpg)
Star catalogue comparison
a tool to improve asteroidal prediction accuracy
Dave Herald, TTSO4, April 2010, Canberra
![Page 2: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/2.jpg)
before HIPPARCOS• Accuracies generally worse than 0.2”• Systematic errors in both RA and Dec• A good prediction had an uncertainty
of ~1000km
![Page 3: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/3.jpg)
Hipparcos• Removed systematic errors• Precision of Hipparcos ~0.001” for
100,000 stars (most stars brighter than ~8)• Proper motions determined from
motions over the 4-year mission duration
![Page 4: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/4.jpg)
Tycho2• Part of Hipparcos• Lower precision ~.02”• Coverage to about mag 12• Proper motions – from
comparison with old astrometric catalogues
![Page 5: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/5.jpg)
Results from Hipparcos/Tycho2
• Hipparcos/Tycho2 removed major source of uncertainty• Asteroid orbits improved after
several years, as observations in the Hipparcos reference frame grew in number• Typical uncertainty <200km
![Page 6: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/6.jpg)
UCAC2• First post-Hipparcos large-scale
astrometric catalogue covering the ecliptic [-90° to +45°]
• Coverage – mags 8 to 16• Accuracy – better than Tycho2• Proper motions from comparison with
old catalogues
![Page 7: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/7.jpg)
Recent catalogues• UCAC3 – 101M stars, whole sky. Has some
specific issues affecting up to 5% of stars• UCAC4 – due in 2011. Whole sky• CMC14 – 95M stars, +50° to -30°. Similar accuracy
to UCAC. No proper motions• PPMX – 18M stars, whole sky. Independent
measures included for ~half the stars. Similar accuracy to UCAC
• 2MASS – near-infrared catalogue. 470M sources. Whole sky. Similar accuracy to UCAC for many stars. No proper motions
![Page 8: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/8.jpg)
Recent catalogues
![Page 9: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/9.jpg)
Compare catalogues• Positions always differ• Catalogue errors become apparent• Assess commonalities and
differences• Compare formal uncertainties• Identify existence of relevant notes
in the source catalogues
![Page 10: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/10.jpg)
Comparison screen
![Page 11: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/11.jpg)
Comparison Graphic
![Page 12: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/12.jpg)
Comparison text 1
Magnitudes
Current position
![Page 13: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/13.jpg)
Comparison text 2
Uncertainty infoFlags
![Page 14: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/14.jpg)
Comparison text 3
Catalogue positions
![Page 15: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/15.jpg)
Ex 1
![Page 16: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/16.jpg)
Ex 2
![Page 17: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/17.jpg)
Ex 3
![Page 18: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/18.jpg)
Ex 4
![Page 19: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/19.jpg)
Ex 5
![Page 20: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/20.jpg)
Ex 6
![Page 21: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/21.jpg)
Ex 7
![Page 22: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/22.jpg)
Ex 8
![Page 23: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/23.jpg)
May 7 Anneliese – mag 6.5 over Melbourne #1
![Page 24: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/24.jpg)
• Nice observation consistent with PPM position – BUT residuals from NICE generally not good.
• Prefer PPMX to Hipparcos. Plan on south shift in path of 0.4 path widths
May 7 Anneliese – mag 6.5 over Melbourne #2
![Page 25: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/25.jpg)
Nice tool! Yes, that is the way to go for your application. Putting together all available catalog data for a specific star is advisable and with your knowledge of star catalogs and the individual positions and motions given inthe catalogs you draw good conclusions.
![Page 26: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/26.jpg)
Access requirements• Occult 4.0.8.16 or later
• If Occult installed, can access from OccultWatcher – ver 3.2.0.5 or later
![Page 27: Star catalogue comparison a tool to improve asteroidal prediction accuracy Dave Herald, TTSO4, April 2010, Canberra.](https://reader036.fdocuments.us/reader036/viewer/2022062618/5513c46955034674748b46df/html5/thumbnails/27.jpg)
Any questions?