Observing Proposal project
Here's the situation: the Director of Kitt Peak Observatory has announced that there will be 6 nights (and only 6 nights) of "Director's Discretionary" time available on the 4m telescope over the next 12 months while it is equipped with the CCD Mosaic imager. You all get to write observing proposals to use the telescope.
Things to consider:
- You propose for one scientific project.
- You proposal must ask for at least one night of observing (and six nights maximum, of course).
- You can apply for at most two observing runs during the year to complete the project.
- You are restricted to using the CCD Mosaic 1.1 imager. Details of the instrument:
Note on using the exposure time calculator:
- Pick an interesting scientific question. (The only ones you cant pick are 1) studying the surface brightness and color profile of a nearby galaxy, or 2) searching for AGN in clusters. We're already doing those in class!)
- What imaging data do you need to answer it (what filters do you need, how bright are your objects)?
- What signal-to-noise do you need for your data? (The best you can do with photometry is probably about 0.02 mags -- if you need better accuracy than this, your project isn't viable.)
- How much observing time would you need? (Use the exposure time calculator to estimate this). Add 20% to the expected exposure times to account for overhead (reading out the CCD, moving telescope, taking calibration data, etc).
- Note on exposure times:
- If you get exposure times that are less than ~ 5 minutes, that means you are looking at very bright objects that don't need such a big telescope (and your proposal would be rejected). Think about fainter objects.
- If you get exposure times greater than 20 minutes, break your observations down into shorter exposures. So for example, if you need an exposure time of 2 hours, break that up into 6 exposures of 20 minutes each.
- If your object is too big to fit in the field of view of the telescope, do you only study a portion of it (with long exposures), or a cover it with many shorter exposures?
- If you are studying a single object, make sure the object is visible for your observations! Objects should only be observed at reasonably high elevations (secz>1.5)
- If you are studying a sample of objects, how many do you need to study, and why?
The exposure time calculator assumes you are doing photometry of individual stars, i.e., point sources. So it works well for giving you an estimate of exposure time to image a star of a given total magnitude.
But if you are looking at extended sources (like galaxies, which are spread over many pixels), the calculation will give you the wrong answer. If you want to measure a large object down to a given limiting surface brightness (in mag/arcsec^2) -- for example, measure the surface brightness of a nearby galaxy, it's more complicated, and the calculator can't handle it. So for our purposes, if you simply enter a magnitude that's 1 mag brighter than your desired surface brightness (so m = mu + 1), that will get you in the right ballpark. Don't attempt this for surface brightness fainter than ~ 27, though. (And don't use this kludge for a real observing calculation!)
And also, if your galaxies are very small (a few arcsec across, like galaxies in a high redshift cluster), just treat them like point sources -- use their total magnitudes and run the calculator like you would on stars, but set the seeing to be sqrt(seeing^2 + angular size^2).
These kludges are pretty crude, so if you are doing an exposure time calculation for an extended source, check in with me to make sure you're getting reasonable values.
Proposal Structure and FormatCover Page (one page maximum):
- Your name and contact information
- An abstract describing your science
- A summary of the observations: how many nights, what time of year
Scientific Justification (two pages, single spaced. If you're writing less than this, you're not being thorough; if you're writing more, you're not editing yourself well.):
- Explain the background: why the science is important, what we want to learn.
- Pose a scientific question that you are trying to answer.
- Explain how the observations you propose will answer your question. What will you do with the data? There should be some interpretive/comparative component to your project.
- Remember that your audience is astronomers, but not necessarily a specialist in your field. You may be explaining quasar spectroscopy to somebody who images planetary nebulae for a living, for example. So you need to convince them that your science is interesting.
- PROPER ACADEMIC REFERENCING IS REQUIRED. Poor referencing practices is a sure sign of a poorly written or poorly researched project. See the example proposal.
Figures and References (a page or two max):
- Your reference list is not part of your justification.
- Its often helpful to have a couple of figures which illustrate the particular point you are trying to get across. Examples of data already taken (by you or others), plots that show a relationship you are trying to test, etc.
Technical Description of Observations (one page):
- Description of the object you are observing (size, magnitude, etc). If you have a large sample of objects, give some characteristic examples.
- Signal-to-noise considerations
- Writing, spelling, grammar, formatting ALL COUNT. Pay attention to detail. Proofread, spell-check, etc. A sloppily written proposal will get tanked in the review process!
- The proposal should be word-processed, not handwritten, and it should be single-spaced.
- Your proposal will not only be graded by me, but also "peer-reviewed" by your classmates.
Proposal Review Criteria