PHY 517 / AST 443 - Observational Techniques
ESS 450, Mondays and Wednesdays 8:00pm - 10:00pm (TBD)
General Information |
Course Description |
Course Schedule |
Observing Calendar |
Computing Resources |
- Credits: 3 (PHY 517) or 4 (AST 443)
- Instructor: Stanimir Metchev (metchev 'at' stonybrook.edu;
ESS 452; 632-1302)
- Matthew Wahl (mjwahl27 'at' gmail.com; ESS 443B)
- Andrea Massari (an.maxar 'at' gmail.com)
- Required texts:
- The required textbooks are available at the bookstore or through
amazon.com, by following the above links
- Prerequisites: AST 203 or 205 for undergraduates: may be taken
concurrently; no prerequisites for graduate students
Astronomers explore the universe by detecting and analyzing photons
with energies ranging from about 51 Joules to 10-9eV, or
a range of about 30 orders of magnitude. One needs very different techniques
over this range. We concentrate on a subset of techniques for detection
of photons from visible to radio wavelengths.
This is a three-quarters lab and one-quarter lecture course. The
laboratory component entails obtaining and analyzing astronomical data with
optical and radio telescopes. Three distinct observational experiments
will be conducted, focussing on optical photometry/time-series analysis,
optical spectroscopy, and radio interferometry. The students will be
responsible for setting up and calibrating their telescope equipment,
obtaining their own data, and analyzing the data in
the IDL programming language.
The lecture component is intimately intertwined with the experimental
aspects of the course. During a total of eight lecture periods the
students will learn the basics of telescope and detector technology, the
use of photometric, spectroscopic, and interferometric techniques, and
methods of error, statistical, and time-series analysis.
The last of the three observational projects will involve writing a
telescope observing proposal that will be peer-reviewed. The observing
proposal will emphasize the need for generating a testable hypothesis and
justifying it through signal-to-noise or other appropriate statistical
arguments. The peer evaluations will not affect the proposer's grade, but
will rather serve to assess the evaluator's ability to critically assess
the quality of the other proposals.
The students will prepare journal-style written reports on each of their
observational projects and a final oral or poster presentation on one of the
- Lecture 2, Feb 4 and 7, 2013,
- Lecture 3, Feb 18, 2013,
Photon Detectors, Spectrographs
- Lecture 4 and Prof. Koda's radio
astronomy slides, Feb 28, 2013,
Radio Astronomy and Interferometry
- Lecture 5, Mar 11, 2013,
Statistics, Error Analysis, and Hypothesis Testing
- Lecture 6, Apr 1, 2013,
Writing Telescope Proposals
- Lecture 7, Apr 25, 2013,
Time Allocation Committee
- General guidelines:
- The guidelines are mostly identical to those laid out in the course notes for PHY 515 / 445.
This is mandatory reading.
- The following notes are specific
to PHY 517 / AST 443. (Also mandatory.)
- Group A. Imaging and Photometry
- 1. Transiting extrasolar planets.
Perform time-series photometry of stars with known transitng
planets. Multiple measurements are needed to attain precision
at the 0.1% level, needed for detecting planet transits. This
is an exercise in obtaining high-precision measurements and in
- 2. Interstellar dust extinction.
Measure stellar fluxes in astronomical images in three different
electromagnetic bands. Build a color-color diagram, i.e., a
diagram of the flux ratios among the bands, for an extincted
globular cluster in the galactic plane and compare it to the
known colors of stars with no dust extinction. The offset
between the two sets of (extincted and non-extincted) data gives
the extinction vector and hence the amount of
interstellar dust along the line of sight toward the globular
- Group B. Spectroscopy
- 1. Elemental abundances in gaseous nebulae.
The determination of heavy element abundances in emission-line
nebulae provides an opportunity to study the gaseous environment
in star-forming regions. Measure
emission line strengths for different species. Infer
gas temperatures and electron densities.
- 2. The Spectrum of Earthshine: Detecting
Earth's Biosignatures from Afar.
Obtain a low resolution optical spectrum of the faint glow from
the dark side of the Moon: sunlight that is doubly reflected
from the Earth's and the Moon's surface. Proper calibration
with respect to singly-reflected sunlight from the bright side
of the Moon can reveal the visible spectrum of the Earth, and
with it the tell-tale signatures of a habitable world: molecular
oxygen, ozone, water, and vegetation.
- Group C. Radio astronomy
- 1. Angular diameter of the Sun.
Michelson interferometry is a technique with broad applications
in both physics and astronomy, and is used to date to directly
measure stellar diameters. The Sun is a marginally resolved
source for our home-built Stony Brook radio telescope when
viewed in single-dish mode, but is well resolved when observed
inteferometrically. Compare an intensity scan of the
Sun to that of a known point source (a geostationary TV
satellite) in single-dish mode and infer the Sun's angular
diameter. Then repeat the experiment with the interferometer,
recording the Sun's and the satellite's visibility amplitudes as a
function of baseline for several different interferometer
baselines. Your interferometrix measurents should yield a much
more accurate solar diameter.
- Test data:
- Student groups:
- Log sheets for:
- Write a telescope observing proposal for the third and last laboratory
- 4 pages maximum, including 2 pages for figures, tables, and object
list. Use a 12-pt font, 1-inch margins, and single spacing.
- Due at 5pm on April 12, 2013 by email
- Will be discussed in class on April 18, 2013
- Mandatory proposal cover sheet
- LaTeX proposal template
- Example proposal
- Proposal review instructions
and grade sheet
- Submitted proposals
- Mt. Stony Brook 14-inch telescope.
Our Department operates the Mt. Stony Brook observatory, housing a
14-inch Meade LX200-ACF telescope. This will be the workhorse
telescope for the imaging and spectroscopic components of the
course. Telescope manual and
Note that the current telescope manual refers to using the CCDOps
software for CCD imaging observations, while you will be using
CCDSoft, which allows more flexibility with guiding.
- Visible-light CCD camera.
Imaging observations with the 14-inch telescope will be taken with
the SBIG STL-1001E CCD camera. The CCD camera is mounted on the back end
of the telescope and is controlled through a laptop computer. A set
of standard broad-band BVRI and a narrow-band H-alpha filters are
information sheet; specifications; operations
manual, CCDSoft quick-start
guide, or CCDSoft v.5 manual.
- Visible-light spectrograph.
Spectroscopic observations will be obtained with a spectrograph that
offers moderate (500-5000) resolution between 3500 - 9500 angstroms.
website (in German) with a sketch of the optical path, step-by-step instructions.
- Radio telescope and interferometer.
Our two-element radio interferometer employs 1-meter aluminum
mirrors to combine
light onto a single 1 meter commercial satellite dish. The interferometer
has an adjustable 2-10 meter baseline and the reflective elements
are well suited for observations at centimeter wavelengths.
Single-dish radio observations can also be taken by
flipping the satellite dish by 180 degrees and pointing it away from
the aluminum mirrors. Step-by-step
- Math/Physics SINC site computers:
- These will be available to you during open SINC site hours.
Make sure that you have an account on them.
- If you need to login remotely, make sure that you have
an Xserver installed on your computer.
- On Mac OS X, you will need X11, which can be
downloaded freely from the Apple site
or you can use the open-source variant XQuartz.
Once you have X11 installed, create an X11 window, and from
the command line type
- On Windows, you will need an Xserver like X-Win32, a licensed
version of which can be found on the Stony Brook DoIT site.
When configuring a new connection, make sure that you
specify 'ssh' as Type and click on 'Linux' for the Command
- If you need extra disk storage space (as you will for the
transit planet lab), log in specifically to compute.mathlab.sunysb.edu and use
one of the two local storage disks linked specifically to
this computer: /space1 or /space2. Make a subdirectory for
yourself on one of the two disks and transfer your files to
your subdirectory. The local storage disks are not backed
up, so make sure to have all important information saved in your
- Setup and initialization of IDL under Unix (for bash shell):
- Add the following lines to the .bashrc file in your home directory:
if [ -f ~/.idlstartup ]; then
- Copy the file .idlstartup in your
- Unix tutorials:
- IDL tutorials and resources:
- Example IDL code. You will need to
tailor these scripts to your files and data, but the programs here can
be used as a strating point.
- Basic CCD image reduction:
- A full sequence of photometry on a transiting planet field,
the coordinates of the individual stars are known. Assumes
that images are well-aligned, as would be obtained from
- Simulates and plots single-dish profiles of the Sun and of a
- Astronomical FITS image viewing programs:
- SAOImage DS9
an interactive display tool for IDL
- Literature search:
NASA ADS: virtually all literature of astronomical interest
can be found here.
- astro-ph: the
most up-to-date resource (updated daily), but incomplete.
- Typesetting in LaTeX:
- You are required to typeset your lab write-ups in the format
of the American Astronomical Society (AAS) journals. Here is a
sample. The LaTeX set of files
needed to produce this are archived here.
You are welcome to use any text editor to produce this result.
Should you choose LaTeX, AASTeX v5.2
(LaTeX 2e) is installed on the Math/Physics SINC computers.
- Refer to the AASTeX package
page for examples and hints on using AASTeX.
- You are encouraged to use Natbib and
AstroNat (a BibTeX package) to manage your
citations. A copy of the Natbib style file is included with the AASTeX
package, but AstroNat
will require your own installation.
- Other tools:
- Stellarium: a free
open source planetarium for Windows/MacOSX/Linux. You may find it
useful for finding your targets on the sky.
calculator: for your observation planning
The course grades will be assigned on the basis of the following:
- 75% projects and written reports (25% each)
- 10% observing proposal
- 10% final presentation
- 5% evaluation of peers' proposals and presentations
- Lecture notes: Select slides will be available after each lecture on the course website.
- Late work: Assignments up to
one week old will be accepted with a 25% penalty. More than one week
overdue assignments will not be accepted.
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