Course Hero Logo

P16 Star Trails and Sidereal Day.pdf - Using Star Trails to...

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 1 - 2 out of 2 pages.

Using Star Trails to Measure the Sidereal DayPost-16Topics covered:Earth’s rotation, night sky photography, angles, arcsThe stars rotate around thenorth and south celestial polesthese are points in the skyabove the north and southpoles of the Earth. The starPolaris marks out the northcelestial pole. The stars Dubheand Merak in the Plough pointto Polaris making it easy tofind in the night sky.Credit: Peter Michaud (Gemini Observatory), AURA, NSFStars take23 hours 56 minutes and 4 secondsto make one completerevolution around a celestial polethis is the time it takes the Earth torotate once around its axis andit’scalled thesidereal day.ActivityTake long-exposure photographs of the circumpolar stars around Polarisor the south celestial pole and use them to determine the length of thesidereal day.You will need a compact bridge or DSLR camera for this and you mayneed to spend some time adjusting the settings to get the best images(see our how-to guides below). You will need a long exposure to get largestellar arcs that can be easily measured however light pollution willswamp the CCD within a 3 minute exposure unless you are in a very dark

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 2 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Winter
Professor
bennert
Tags
celestial pole, Polaris, Pole star

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture