Calendar

Dec
4
Fri
Colloquium: Brian Jackson
Dec 4 @ 3:15 pm – 4:15 pm
Colloquium:  Brian Jackson @ BX102

On the Edge: Exoplanets with Orbital Periods Shorter Than a Peter Jackson Movie

Brian Jackson, Boise State Univeristy

From wispy gas giants to tiny rocky bodies, exoplanets with orbital periods of several days and less challenge theories of planet formation and evolution. Recent searches have found small rocky planets with orbits reaching almost down to their host stars’ surfaces, including an iron-rich Mars-sized body with an orbital period of only four hours. So close to their host stars that some of them are actively disintegrating, these objects’ origins remain unclear, and even formation models that allow significant migration have trouble accounting for their very short periods. Some are members of multi-planet system and may have been driven inward via secular excitation and tidal damping by their sibling planets. Others may be the fossil cores of former gas giants whose atmospheres were stripped by tides.

In this presentation, I’ll discuss the work of our Short-Period Planets Group (SuPerPiG), focused on finding and understanding this surprising new class of exoplanets. We are sifting data from the reincarnated Kepler Mission, K2, to search for additional short-period planets and have found several new candidates. We are also modeling the tidal decay and disruption of close-in gaseous planets to determine how we could identify their remnants, and preliminary results suggest the cores have a distinctive mass-period relationship that may be apparent in the observed population. Whatever their origins, short-period planets are particularly amenable to discovery and detailed follow-up by ongoing and future surveys, including the TESS mission.

Tombaugh Observatory Open House
Dec 4 @ 7:00 pm – 9:00 pm
Tombaugh Observatory Open House @ Tombaugh Observatory

Open to the public.

Faculty member: James Murphy

Graduate Students: Jacob Vander Vliet, Kyle Uckert

 

 

Dec
7
Mon
Pizza Lunch: Chunming Zhu
Dec 7 @ 12:30 pm – 1:30 pm
Pizza Lunch: Chunming Zhu

TBD

Mar
4
Fri
Colloquium: Gail Zasowski (Host: Drew Chojnowski)
Mar 4 @ 3:15 pm – 4:15 pm
Colloquium:  Gail Zasowski  (Host: Drew Chojnowski) @ BX102

New Tools for Galactic Archaeology from the Milky Way

Gail Zasowski, John Hopkins University

One of the critical components for understanding galaxy evolution is understanding the Milky Way Galaxy itself — its detailed structure and chemodynamical properties, as well as fundamental stellar physics, which we can only study in great detail locally.  This field is currently undergoing a dramatic expansion towards the kinds of large-scale statistical analyses long used by the extragalactic and other communities, thanks in part to an enormous influx of data from space- and ground-based surveys.  I will describe the Milky Way and Local Group in the context of general galaxy evolution and highlight some recent developments in Galactic astrophysics that take advantage of these big data sets and analysis techniques.  In particular, I will focus on two diverse approaches: one to characterize the distribution and dynamics of the carbon-rich, dusty diffuse ISM, and one to map the resolved bulk stellar properties of the inner disk and bulge.  The rapid progress in these areas promises to continue, with the arrival of data sets from missions like SDSS, Gaia, LSST, and WFIRST.

Apr
29
Fri
Colloquium: Betsy Mills (Host: Moire Prescott)
Apr 29 @ 3:15 pm – 4:15 pm
Colloquium:  Betsy Mills (Host: Moire Prescott) @ BX102

Do star formation laws break in the center of the Galaxy?

Betsy Mills, University of Arizona

I will review our understanding of molecular gas conditions in the central 500 parsecs of the Milky Way, and summarize recent studies that find that the Galactic center deviates from universal star formation relations. It is suggested that the amount of star formation in the Galactic center is less than expected, given the quantity of dense gas in this region. However, in order to conclude that the Galactic center truly breaks these ‘laws’ of star formation, two possibilities must be ruled out: that our indicators in this region could underestimate the amount of star formation, and that prior observations could have overestimated the amount of dense gas. I will analyze new evidence for ongoing star formation in the Galactic center and present new measurements of the gas densities in the Galactic center that show it to be less dense than originally thought. However, I will ultimately argue that the average density of the gas is less relevant to explaining the dearth of star formation than the fraction of gas at each density.

 

Sep
20
Tue
Colloquium Thesis Proposal: Ethan Dederick
Sep 20 @ 3:00 pm – 4:00 pm
Colloquium Thesis Proposal: Ethan Dederick @ Science Hall 310

Utilizing Planetary Oscillations to Constrain the Interior Structure of the Jovian Planets

Ethan Dederick

Seismology has been the premier tool of study for understanding the
interior structure of the Earth, the Sun, and even other stars. Yet in this
thesis proposal, we wish to utilize these tools to understand the interior
structure of the Jovian planets, Saturn in particular. Recent observations
of spiral density structures in Saturn’s rings caused by its oscillations
have provided insight into which modes exist within Saturn and at what
frequencies. Utilizing these frequencies to compare to probable mode can-
didates calculated from Saturn models will also us to ascertain the interior
profiles of state variables such as density, sound speed, rotation, etc. Using
these profiles in a Saturn model, coupled with tweaking the interior struc-
ture of the model, i.e. the inclusion of stably stratified regions, should
allow us to explain which modes are responsible for the density structures
in the rings, as well as predict where to look to find more such structures.
In doing so, we will not only have a much greater understanding of Sat-
urn’s interior structure, but will have constructed a method that can also
be applied to Jupiter once observations of its mode frequencies become
available. In addition, we seek to explain if moist convection on Jupiter is
responsible for exciting its modes. We aim to do this by modeling Jupiter
as a 2D harmonic oscillator. By creating a resonance between moist con-
vective storms and Jovian modes, we hope to match the expected mode
energies and surface displacements of Jupiter’s oscillations.

Apr
3
Mon
Pizza Lunch: Nancy Chanover & James McAteer
Apr 3 @ 12:30 pm – 1:30 pm
Pizza Lunch: Nancy Chanover & James McAteer

The AAS: What Has it Done for You Lately?

Oct
16
Mon
Pizza Lunch: Ken Naiff
Oct 16 @ 12:30 pm – 1:30 pm
Pizza Lunch: Ken Naiff @ AY 119

Dark Sky Images

Ken Naiff

Ken, an retired engineer, is a highly technically skilled and artistic
astrophotographer.  He will be sharing some of his work and elaborating on
the technical methods and processing techniques he applies to obtain his
unique and enhanced images.  You can see Ken’s work at:

https://darkskyimagesbyken.com/products

 

Apr
6
Fri
Colloquium PhD Thesis Defense: Sten Hasselquist
Apr 6 @ 3:15 pm – 4:15 pm
Colloquium PhD Thesis Defense: Sten Hasselquist @ BX102

Colloquium Title

Sten Hasselquist, NMSU

Abstract

Nov
5
Mon
Pizza lunch: Heidi Sanchez
Nov 5 @ 12:30 pm – 1:30 pm
Pizza lunch: Heidi Sanchez @ AY 119

The Sunspot Solar Observatory Visitor Center

Heidi Sanchez, Sunspot Solar Observatory, NMSU