Main-Belt Asteroids

Project Aims

• to determine the orbital parameters (and their associated uncertainties) of a set of Main Belt asteroids from astrometric measurements from images taken at both Durham and the La Palma pt5m.
• to extend the base-line of the analysis by using image data from the AstroLab archive
• to measure the distance of a main-belt asteroid from using observations from Durham and La Palma taken at the same time and hence determine a value for the Astronomical Unit (AU)

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 a set of at least six main belt asteroids; in order to extend the base-line select an asteroid that has previous measurements from Durham
   • Determine when your targets can be best observed; load the known orbits of your targets into the ECU software
   • 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)
   • Use the provided Python scripts to independently measure the astrometric positions of your targets
   • 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 for the fainter Hyades targets) and measure their astrometric positions relative to stars on the CCD images

   • Ideally you will be able to observe your asteroids on about seven separate occasions during the term and acquire data from the pt5m on La Palma for a similar number of occasions
   • For a well-placed main-belt asteroid acquire some observations from La Palma at the same time obervations are being undertaken at Durham; this will allow the asteroid's distance to be measured and the AU measured
   • How do your measured positions depend on the choice of stars used to define the astrometric mapping?
   • How do your measured asteroid 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. Use your observations from Durham and La Palma to determine the distance to one of your targets

   • How well can the distance to the asteroid be determined and what are the main uncertaintes
   • How well can a value of the AU be found from this technique
   • Write-up your results and conclusions

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jrl

2020-Jun-17 13:34:47 UTC