Star and Planet Formation Discussion Group
 Thursday Meetings

  Bryant conference room (217)

NEXT MEETING:
  Sep. 17, 11:30 am

  Phil Armitage (U. Colorado - Boulder)
Planet Scattering with Small Body Disks


Fall/Winter 2009 schedule  

Nov. 12
 Adam Kraus (Caltech)

Stellar Multiplicity and Planet Formation


Oct. 15
 James De Buizer (Stratoshperic Obseravtory for Infrared Astronomy)

Unexpected Observational Properties of Massive Young Stellar Objects in the Mid-Infrared


Oct. 1 Betsy Barton (UC Irvine)

Star Formation and Gas in the Lowest-Density Environments


Sep. 17 Phil Armitage (U. Colorado - Boulder)

Planet Scattering with Small Body Disks


August 20 Tsevi Mazeh (Tel Aviv Univ.)

TODCOR (and TRICOR):  How to derive radial velocities from composite spectra




Winter/Spring 2009 schedule  

April 30
 Dan Whalen (LANL), Rafael Guzman, Jonathan Tan (UF)

 Discussion on: The First Stars


April 23 Mike Butler (UF)

The Structure of Dense Cores: Probing the Initial Conditions of Massive Star Formation

Yichen Zhang (UF)

SEDs and Images from Radiation Transfer Code for Massive Star Formation


March 26
 Franz Bauer (Columbia)

The Nature of the Faint Radio Source Population in the Chandra Deep Fields

Abstract

 

The depth and breadth of the pan-chromatic coverage in the Chandra Deep 
Fields is unrivaled over the entire sky, and includes extremely deep 20cm 
and mid-IR surveys. Since radio and mid-IR emission are considered robust 
tracers of star formation (e.g., the radio-IR correlation), these datasets 
can be used to improve our overall understanding of star-forming galaxies 
out to z~1.5. I will discuss some preliminary results to identify and 
constrain the nature of the faint uJy radio source population, touching 
upon the potential evolution of radio-IR correlation and problems with AGN 
contamination.
March 5
 Greg Bryan (Columbia)

On Transition from Population III to Population II Stars


January   30
UF-UCF Star & Planet Formation Day


Program
January 29
 Sarah  Dodson-Robinson (EXScI, JPL)

Planets, Silicon & Iron:
How to isolate the relationships between several correlated variables with the K-S bootstrap test

Abstract
I present a new statistical method, the K-S bootstrap test, that isolates the relationship between two random variables when both quantities are known to correlate strongly with a third random variable. The problem arose as follows: I wanted to find out whether giant planets mainly orbit stars with high silicon abundance, rather than stars with low silicon abundance. (Since giant planet cores are composed mainly of silicate rock, silicon-rich star systems should form planets much more easily than silicon-poor systems.) However, a star's silicon content is strongly correlated with its iron content, and astronomers have observed that planets usually orbit iron-rich stars. I needed a way to test my hypothesis that silicon-rich star systems readily form planets, while making sure I wasn't just re-discovering the known planet-iron correlation.
    Here I describe the statistical analysis that led to the discovery that stars with planets are indeed silicon-rich, independent of their iron content. I also discuss applications of the K-S bootstrap test to other areas of science. For example, the K-S bootstrap test could help answer the following questions:
* How effective is tobacco-prevention education? School districts with aggressive anti-smoking curricula may be preferentially located in areas with high cigarette taxes, which also discourage smoking.
* Is obesity truly a cause of heart disease? Many people labeled "obese" according to height-weight charts have normal blood pressure and cholesterol, eat healthful diets and get regular exercise. Answering this question requires isolating the various influences of genetics, diet, exercise, thyroid function and more.
January_22        
Peter Anders (Utrecht)

A New Challenge to Old Clusters





Fall/Winter 2008 schedule   

December 4
 Joshua Pepper (Vanderbildt)

KELT and the Search for Transiting Exoplanets

Abstract
I will talk about the current state of exoplanet discovery,
giving a brief background about the field, and focusing on transit
surveys.  I will talk about the KELT survey for transiting exoplanets, and
about the coming collaboration between KELT and MARVELS.
The talk will be broadly based, explaining the science of transits at a
basic level, and discussing the basic questions about searching for
exoplanets and the power of transits.  I will place KELT in the context of
the current state of the field.
November 20
 Jessica Lu (Caltech)

A discussion of kinematics in star forming regions

Suggested reading
Kinematic Structure of the Orion Nebula Cluster and its Surroundings
November 6
 Alberto Bolatto (Maryland)

Spitzer Surveys of the SMC


October 24-25
UF-UCF Starformation Day


Program
October 2
 Alice Quillen (Rochester)

Spitzer observations of Cen A's Nuclear shell and models for episodic star formation

Abstract

 

Spitzer observations of Centaurus A have revealed a kpc sized shell-like 
structure in its center. I will explore possible scenarios accounting for 
the spectral and morphological properties of the shell. I will review a 
wide range of observational settings that suggest that star formation can 
be episodic. Some observations of galaxies imply that due to feedback,
star formation can approach a self-regulating steady rate. Other settings, 
such as the central kpc of Centaurus A, imply that episodes of enhanced 
star formation can be followed by periods of quiescence.   Using simple 
differential equation models previously used to model biological population
dynamics, I will account for these two behaviors, and classify models 
according to parameters describing feedback and gas consumption. Future 
applications of these and similar models may be powerful.
Sept 18
 Steinn Sirgudsson (Penn State)

Post-colloquium discussion on Exotic Earths


Sept 4
 Eric Ford, Dimitri Veras(UF)

Overview of the "Extra-solar planets in multi-body systems" conference,
held August 25-29 2008 in Torun(Poland)


Conference page


Winter/Summer 2008 schedule

July 17
Welcoming new SPF folks



June 5
 Eric Ford, Dimitri Veras, Scott Fleming (UF)

Summary of the IAU Symposium on Transiting Planets


IAU Symposium 253, Boston, May 19-23 2008
April 17 Nadya Gorlova (UF)

Free discussion / Article review

Suggested reading
Disk around an old star (2008 Zuckerman et al.)

On the Binary Nature of Dust-encircled BD+20 307 (2008 Weinberger)
April 10
 David Bennett (Notre Dame)

Microlensing Planet Search


March 20
 Cynthia Gomez Martin (UF)

Article review

Suggested reading
Hubble Space Telescope NICMOS Observations of NGC 1333: The Ratio of Stars to Substellar Objects (Greissl et al. 2007 AJ)
March 13
 Nadya Gorlova (UF)

Summary of the winter school "Early Phases of Planet Formation"


School page with downloadable presentations
February 14
Regular meeting


February 1
UF-UCF Starformation Day


Program
January 17
Discussion of AAS and the Starformation Newsletter
(Dec 2007 issue)

Suggested reading
SF Newsletter page



Fall/Winter 2007 schedule

Novemver 29
 Brian Lee (UF)

Selection of Target Stars for MALRVELS (a Radial Velocity Planet Survey)


Novemver 15 Nadya Gorlova (UF)

On the Correlation Between Stellar Mass and Planet Incidence (article review)


Suggested reading
A new planet around M dwarf: revealing a correlation between exoplanets and stellar mass
Johnson et al. (astro-ph / 16 Jul 2007)

Planet formation around stars of various masses: the snow line and the frequency of giant planets
Kennedy & Kenyon (astro-ph / 4 Oct 2007)
Novemver 1
 Dimitri Veras & Suvrah Mahadevan (UF)

Summary of the DPS Meeting in Orlando



October 11 Fabian Heitsch (Michigan)

TBD



October 04
 Eric Ford (UF)

Characterizing the Orbital Eccentricities of Transiting Extrasolar Planets with Photometric Observations

Abstract
The discovery of over 200 extrasolar planets with the radial velocity        
(RV) technique has revealed that many giant planets have large
eccentricities (Butler et al. 2006), in striking contrast with most
of the planets in the solar system and prior theories of planet
formation.  The realization that many giant planets have large
eccentricities raises a fundamental question: ``Do terrestrial-size
planets of other stars typically have significantly eccentric orbits
or nearly circular orbits like the Earth?''  On one hand, the idea
that our solar system is special appears to fly in the face of the
Copernican principle. On the other hand, most of the known giant
planets of FGK stars have sizable eccentricities, and these
eccentric giant planets would inevitably perturb the orbits of any
nearby terrestrial planets.  Here, we demonstrate that photometric observations
of transiting planets could be used to characterize the orbital eccentricities for
individual transiting planets, as well the eccentricity distribution for various
populations of transiting planets (e.g., those with a certain range of orbital
periods or physical sizes).  Such characterizations can provide valuable
constraints on theories for the excitation
of eccentricities and tidal dissipation.  We outline the
future prospects of the technique given the exciting prospects for
future transit searches, such as those to be carried out by the CoRoT
and Kepler missions.