Observing Proposal project
Here's the situation: the Director of Kitt Peak Observatory has announced that there will be several nights of "Director's Discretionary Time" available on the telescopes over the next 12 months. Time is available on two telescopes, while equipped in imaging mode:
- The Kitt Peak 4m: 4 nights using the CCD Mosaic imager
Your task is to write an observing proposal to use one (or both) of these facilities to do some science.
- The WIYN 0.9m: 7 nights using the HDI imaging camera
Things to consider:
- You propose for one scientific project.
- You proposal must ask for at least one full night of observing.
- You can apply for at most two observing runs during the year to complete the project.
- You can ask for time on both telescopes, but they must be different runs.
Note on using the exposure time calculator:
- Pick an interesting scientific question. If you are having trouble choosing on a topic, there are a few possibilities at the bottom of this page. (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 doing those projects 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). If you get this on the 4m, try the 0.9m telescope. If you get this on the 0.9m telescope, 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? When is the best time to observe them?
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. So if you are doing a project involving photometry of individual stars, you must use the exposure time calculators.
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 extended sources, you can do one of two things to estimate exposure times:
Marginally resolved sources: 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).
- Estimate it by previous studies. Find a similar project in the literature that uses the same class of telescope and the same filters as your project, and gets to the accuracy that you need. Adopt their exposure times.
- Kludge it. What is the surface brightness limit you need to reach?
With that surface brightness, work out the magnitude of a 10x10 arcsec
patch. Then enter that magnitude into the expsoure time calculator, and
enter 10" for the seeing (and aperture). This will get you in the right
ballpark, as long as you don't go fainter than ~ 27 mag/arcsec2.
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 FormatNote: the page length descriptions by section are different from what you see in the example proposals. Follow the instructions here!
Cover 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.
- Justification for the choice of telescope
- Justification for the allocation request (signal-to-noise considerations, exposure times, time of year, etc)
Proposal Review Criteria
- 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.
Possible Projects (the list is endless!)
- Finding the distance, age, and metallicity of a Milky Way globular cluster via isochrone fitting
- Studying the properties of galaxies in clusters
- Studying the distances to a sample of Milky Way satellite galaxies using tip of the red giant branch (TRGB) estimates
- Searching for variable stars in globular clusters or satellite galaxies
- Studying the properties of the globular cluster systems around other galaxies
- Studying the chemical composition of Kuiper Belt objects (or asteroids) through their colors.
- Age dating open star clusters in the Milky Way
- Searching for high redshift galaxies around distant quasars