Astronomy 110
General
Astronomy 110, Observational Astronomy, is strictly a laboratory course. There will be 3 or 4 classroom sessions during the semester, at times to be announced later. Otherwise, we will be meeting at the observatory, once or twice a week. Tentatively, subject to the vagaries of weather and also student schedules, we will try to meet on Monday and/or Thursday nights (this could change). It may be necessary to modify this schedule to suit individual students. We will try to get in three hours of observing each week. We have a classroom, Jones 204, from 5-9 on Thursday nights, but will not often use it.
The course grade will depend entirely on laboratory/observing laboratory reports and a lab notebook which you will be expected to keep during the entire semester. Some projects will take a few to several weeks to complete, others can be completed in one session. I will give due dates for each project, but if the data are collected in only one session, the report will be due in two weeks.
The class will be divided into 3-4 groups of 3-4 each. I will try to have two groups taking data and one preparing to do so, at each session.
Finally, we will attempt to schedule a field trip north of Lake Pontchartrain
to a dark sky location for mostly visual work. This would likely be in
mid to late October or early November, during the dark of the Moon. These
constraints mean we would go before Oct. 15 or Nov. 1-10 or so, probably on a
friday evening.
Observing projects (tentative list):
I. Digital (and possibly film) photography of the Moon; measurement of heights and diameters of lunar features
II. Webcam imagery of Jupiter and Mars; possibly Venus
III. CCD imagery of galaxies, clusters, nebulae and binary stars
IV CCD photometry of variable stars including exoplanet?
V Stellar spectroscopy
VI Sloan Digital Sky Survey project
VII Solar imaging using H-alpha filter and digital camera
VIII Observation of Jupiter’s Galilean moons.
IX. Algol naked-eye observing project
X Miscellaneous: observations of one or more asteroids, a comet, if possible, and the moons of Uranus
Descriptions:
I. Photography of the Moon.
Photography of lunar features using a conventional digital camera, and measurement of heights of lunar features from shadow length and sun angle, as well as crater diameters, etc. This will require use of a filar micrometer. Simple measurments with a filar micrometer and simple trigonometry will yield heights and linear measurements.
II. Webcam imagery of Jupiter and Mars
Jupiter will be visible at the beginning of the semester and Mars will be in opposition toward the end. We will use a webcam to accumulate a sequence of video images of the planet, which will then be stacked using Registax or some other software.
III. CCD Imagery of Galaxies, Clusters, and Nebulae
This project will utilize the SBIG ST-7XE CCD camera on the 16-inch LX200. I will have copies of the CCD manual for you to consult and a brief summary of what you need to know. We will select two or three globular clusters and about the same number of galaxies to image. The galaxies will include the Whirlpool, M51, if we can get started early enough in September, probably M33 in Triangulum, and possibly the Andromeda galaxy or one of its companions. The globulars will probably include M13 in Hercules and M22 in Sagittarius. Possibly an open cluster in the Milky Way as well. We will probably also image the Crab Nebula, M1, and perhaps the Orion Nebula, M41, later in the semester. In each case, but especially in the case of the galaxies, we will want to take up to a dozen short exposures and “stack” them, to reduce noise due to our bright night skies. The principle is that the noise is random while the desired image is not, hence averaging a number of images causes the noise to be cancelled out to a considerable degree. The stacking or averaging will be done with software designed for that purpose, either the freeware Registax or some similar package, or MAXIM DL or even Photoshop.
We will image at least one extended object (galaxy, nebula) in color.
The final product will be a set of images of the objects selected.
Your lab report should include information about the telescope focal length or relative aperture (f-number) obtained if a focal reducer is used, the image scale, the exposure times, and the image processing used.
IIIa. CCD Stellar Imaging (Binary Stars, etc.)
At least one binary or triple star system will be imaged. A good example would be 40 Eridani B, a triple star system consisting of a class K sub dwarf, a class M red dwarf, and a white dwarf star.
IV. CCD Photometry
The capability of the CCD camera to measure the brightness of stars will be used to obtain light curves for a small number of binary stars, both intrinsic (pulsating) and eclipsing. The best example of the latter will be Algol, Beta Persei. This project will involve developing the technique, learning how to calibrate the CCD camera to account for sky transparency, sky brightness, altitude, etc.
Ultimately, we may attempt to detect an extra-solar planet as it eclipses its parent star, but measuring small changes in brightness of the star.
The final result will be light curves of the stars involved.
V. Stellar Spectroscopy
I anticipate obtaining a digital spectrograph which we will use to take the spectra of several bright stars of varying spectral type. Part of the project will be learning the use the spectrograph. If the spectrograph is not obtained in time, we will try to use a visual spectroscope and a standard digital camera to obtain spectra of a few very bright stars.
VI. Sloan Digital Sky Survey Project
This will be assigned to be due in one month. This is the primary non-observational project, but it will utilize real imagery being used by professional astronomers to make fundamental discoveries. It will entail learning how to extract data from the SDSS and actually sampling some data, e.g., finding the number of galaxies per square degree brighter than a given magnitude, etc.
VII. Solar Imaging
We are currently just past sunspot minimum (probably 2005-6), so solar activity will be somewhat low. We will observe the Sun in white light and take digital photographs if there are sunspots present. We will also observe the Sun in the light of H-alpha, using a narrow band-pass H-alpha filter. We will photograph the Sun’s “surface” and prominences when present.
VIII. Jupiter’s Moons
We will observe Jupiter’s Galilean moons with a view toward 1) determining their periods of revolution, and 2) timing and perhaps predicting eclipses, shadow passages, etc. We will try to use the latter to determine the speed of light as Romer did, if we can manage to predict the phenomena accurately.
IX. Naked Eye Determination of Algol’s Period
In addition to using CCD photometry to get Algol’s light curve, everyone will be expected to attempt to determine its light curve visually, by comparing it with stars of known magnitude. This can be carried out off and on throughout the semester, or until Algol becomes invisible. Comparision star charts will be furnished.
X. Miscellaneous
We will observe one or more asteroid, a comet if a sufficiently bright one presents itself, etc. We will also have one or more early morning sessions to view and photograph Venus which is just past inferior conjunction in the morning sky just before sunrise. It is now a fairly thin crescent. Observations and CCD photography of Uranus and Neptune will be attempted if time permits. Imaging of Barnard’s Star, the star with the highest proper motion and deduction of the amount of proper motion by comparison with earlier imagery.
For additional images taken at the old Cunningham Observatory or the new Tulane Observatory on the roof of Jones Hall, see my Astronomy 100 homepage