Trojans

Project Aims

• to determine the orbital parameters (and their associated uncertainties) of a set of Trojan asteroids from astrometric measurements take at Durham and La Palma
• by use of archival data, to extend the baseline of observations and derive improved orbital parameters
• measure colour information to compare and contrast the Trojans with main-belt asteroids

Project Notes

1. Learn how to use the telescope and CCD system efficiently

   • Attend the observing training sessions
   • Review the L1 User's Guide material to refresh your understanding of the apparent movement of objects in the night sky
   • Study the provided reference material on the telescope, CCD and software

2. Research background material

   • Understand the aims of the project
   • Study the Web-based information linked from the provided References page
   • Revise the material covered in the "Observational Techniques" part of Level-2 "Stars and Galaxies" module
   • Read Chapter 7 (Astrometry) of "The Handbook of Astronomical Image Processing" by Berry and Burnell
   • Search out additional sources of information

3. Plan your project

   • Select at least six Trojans for study. Include in your selection Trojan asteroids that have previous observations in the archive so that an extended baseline can be used for the orbit determination
   • Estimate the likely exposure times required for your targets
   • How many observations will you need?
   • Plan your project write-up; consult the online DUO Report Format Guide and Marking Criteria

4. Write-up the "Introduction and Background" sections of your project

5. Understand how astrometric measurements are made

   • Study Herbert Raab's paper on "Detecting and Measuring faint Point Sources with a CCD"   (local copy)
   • Assess the random and systematic uncertainties in your astrometric measurements (see e.g. Farnocchia et al.)
   • Write-up your conclusions for your report

6. Observe your targets regularly, as the weather permits, during the term (and request observations with the pt5m on La Palma) and measure their astrometric positions relative to stars on the CCD images

• Ideally you will be able to observe your Trojan asteroids on about seven separate occasions during the term and acquire data from the pt5m on La Palma for a similar number of occasions
• How do your measured positions depend on the choice of stars used to define the astrometric mapping?
• How do your measured Trojan positions compare with those given by JPL's HORIZONS System?
• Write-up your results and conclusions

7. Use the find_orb programme for orbit determination

   • Demonstrate that find_orb gives reliable results
   • Assess the random and systematic uncertainties of find_orb
   • Determine the orbital parameters (and their uncertainties) of your targets
   • Compare your values to the recognised values
   • Research other methods for orbital determination
   • Write-up your results and conclusions

8. Extend the project by:

• Examining how, by using the data from the archive, orbital parameters can be determined with improved precision
• Use colour information to compare and contrast the Trojans with main-belt asteroids
• Write-up your conclusions

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jrl

2020-Jun-17 12:44:09 UTC