EXOPLANETS AND BROWN DWARFS
8.972 Astrophysics Seminar
G (2-0-4), Spring 2007
Wednesdays 4-5:30p in 2-151
Within the last decade, two new branches of astrophysics have emerged:
planets orbiting other stars (exoplanets), and tiny stars that cannot
fuse hydrogen (brown dwarfs). Discoveries in these fields have
revolutionized our understanding of star and planet formation and
revitalized the quest to find extraterrestrial life. This seminar
will review the observations and theories of exoplanets and brown
dwarfs, including recent research. It is intended for graduate
students and advanced undergraduates who have already taken at least
one subject in astrophysics.
Format: weekly 1.5-hr meetings, divided into lecture and discussion of
assigned readings. Evaluation will be based on participation and a
term paper on a topic of the student's choosing.
Feb 7 -- BDs and Exoplanets: History and Overview
Feb 14 -- How to Find a Planet or Brown Dwarf
Feb 21 -- Star and Brown Dwarf Formation
Feb 28 -- Planet Formation I
Mar 7 -- Planet Formation II
Mar 14 -- Interiors of BDs and Exoplanets
Mar 21 -- Statistical Properties of Exoplanets, Planet Migration
Mar 28 -- * SPRING BREAK *
Apr 4 -- Transiting Planets
Apr 11 -- Atmospheres I: BD & Exoplanet spectra
Apr 18 -- Atmospheres II: Chemistry, clouds & convection
Apr 25 -- Multiplicity and other population properties of BDs
May 2 -- Magnetic Activity & Rotation
May 9 -- Astrobiology
May 16 -- Unsolved Problems and Future Prospects
This assignment is intended to be a review of the literature on a
subject that interests you, and not a piece of original research.
However, new and original insights or opinions about the literature
are most welcome!
1. Pick a topic that interests you. The scope should be broad enough
to be interesting, but narrower than the subject of one of our
weekly meetings. You may choose from the list of suggestions
below, or invent your own topic.
2. As a first step in organizing your paper, write down some of the
questions that you intend to answer. If you were reading an
article about your chosen subject, what would you want to know?
3. Email your topic and questions to both of the instructors.
4. Search the literature. Read or scan through enough papers that you
can identify the key articles you will need to read in detail.
Familiarize yourself with the key names in the field.
5. Refine your outline, given what you have learned.
6. Write the paper.
7. Return to step 4. Revise, revise, revise. Lather, rinse, repeat.
Your target audience should be other seminar attendees. Avoid (or
define) any jargon that your fellow classmates would not understand.
The text should be as concise as possible, and no longer than 5000
words (not including the abstract, references, or figure captions).
The abstract should be shorter than 250 words. Key figures or images
should be included, with captions. Citations to the literature should
be of the form "Smith & Jones (2007)" or "Brown et al. (2001)" and a
complete listing of references should be given at the end.
You may use any word processor you want, but if you do not already use
LaTeX for scientific writing, consider this an excellent opportunity
to learn how. To submit the paper, email a PDF file to both instructors.
Your grade will be based entirely on the final version of your paper, which is due on May 16, 2007. You will have the option of turning in a first version of your paper on April 30, in which case you will receive detailed suggestions for improvement.
March 21, 2007: Email your topic and questions to your instructors.
April 30, 2007: (Optional) Submit first version of the paper.
May 7, 2007: Receive graded first version.
May 16, 2007: Submit final version of the paper.
SOME POSSIBLE PAPER TOPICS
The Doppler method: future prospects and ultimate limitations
History of the astrometric method of planet detection
The pulsar planets
Microlensing planet detection
High-contrast imaging from space: interferometer or coronagraph?
What has been learned from secondary eclipses?
How to detect moons of exoplanets
Core accretion versus gravitational instability
The role of vortices in protoplanetary disks
Clues to planet formation from meteorites
Formation of regular moons of Jupiter and Saturn
Formation of ice giants: problems and proposals
The Nice model of the history of the Solar system
The origin of planetary obliquities
The interior of Jupiter
The Brown Dwarf Desert and possible explanations
Eccentric exoplanets and possible explanations
What will Kepler discover?
What do we mean by "the habitable zone"?
Connections between exoplanet research and SETI
On the definition of "planet" and "brown dwarf"
Expected yields of brown dwarfs in future surveys
Uncertainties in the properties of brown dwarfs in young clusters
Strengths and limitations of various methods of finding brown dwarfs
Empirical tests of brown dwarf formation models
The mass function of brown dwarfs - in clusters and in the Solar neighborhood
What is the lowest brown dwarf mass? - observational and theoretical constraints
Deuterium burning in brown dwarfs
Lithium burning in brown dwarfs
Fermi degeneracy in brown dwarf interiors
Spectral classification schemes and classifications at different wavelengths
Spectral diagnostics of temperature, gravity, and/or metallicity in brown dwarf spectra
The effective temperature/luminosity scale - constraints and uncertainties
What will the spectra of Y dwarfs looks like?
Empirical evidence for clouds in the atmospheres of brown dwarfs
Empirical evidence for vertical transport in the upper atmospheres of brown dwarfs
Modeling clouds in brown dwarf atmospheres
Spectral diagnostics of clouds in brown dwarf spectra
The statistical properties of brown dwarf binaries; implications for brown dwarf formation
The widest brown dwarf binaries and their implications
The frequency and characteritics of brown dwarf companions to nearby stars
The orbital properties of brown dwarf binaries
Strengths and limitations of various methods to identify brown dwarf binaries
Optical, X-ray and radio emission from brown dwarfs
Measurements of brown dwarf magnetic fields
The characteristics of flares on brown dwarfs
Magnetic dynamos in brown dwarfs