Date

Speaker

Title

Aug 28

Edward Robinson

University of Texas at Austin

Organizational meeting.

Sep 4

No talk scheduled.

Sep 11

No talk scheduled.

Sep 18

Cynthia Froning

University of Texas at Austin

"Accretion and Outflows in Black Hole X-ray Binaries: Multiwavelength Observations of Swift J1753.5-0127"

Sep 25

Howie Marion

University of Texas at Austin

"Supernova Observations at Near-IR Wavelengths"

Oct 2

Harriet Dinerstein

Affiliation: TBA

"The Hidden Chemical Diversity of Planetary Nebulae"

Oct 9

No talk scheduled, to avoid conflict with the Bashfest 2013 Symposium (on 7-8 October).

Oct 16

Sagi Ben-Ami

Weizmann University, Israel

"Massive star explosions: New results, New instruments"

abstract

Oct 23

Bill Cochran

University of Texas at Austin

"Planets and the Galactic Thick Disk"

Oct 30

Kevin Gullikson

University of Texas at Austin

Talk rescheduled to next week, due to bogus fire alarm in the building.

Nov 6

Kevin Gullikson

University of Texas at Austin

"Searching for Disk-Born Binary Systems"

Nov 13

Natalie Gosnell

University of Wisconsin, Madison

"The Mass-Transfer Formation of Blue Stragglers as Revealed by their White Dwarf Companions"

The formation mechanism of blue straggler stars, defined to be brighter and bluer than the main sequence turnoff in a star cluster, has been a question for almost six decades. The blue straggler population of the old (7 Gyr) open cluster NGC 188 provides a unique opportunity to probe the formation histories of blue straggler stars in open clusters. In comparison to the blue straggler populations in younger open clusters and in globular clusters, the cooler temperatures (6,000 to 6,750 K) and close proximity (2.5 kpc) of the blue stragglers in NGC 188 allow for in-depth high-resolution spectroscopic investigation. Long-term radial velocity studies revealed that over 75% of the NGC 188 blue stragglers exist in binaries with a prevalence of 1000-day periods and a statistical secondary mass distribution that peaks at 0.5 Msolar. Using HST/ACS/SBC far-UV photometry I will present direct observational detections of young (<300 Myr), hot white dwarf companions in three blue straggler binaries. Given the age distribution predicted in full N-body models, which translates into a white dwarf temperature distribution, three detections is consistent with the entire NGC 188 blue straggler population being formed via mass transfer. These detections affirm the prediction made by previous studies that the blue straggler population of NGC 188 is dominated by mass transfer formation.

close

Nov 20

Iair Arcavi

Weizmann Institute of Science / Las Cumbres Observatory Global Telescope

"Revealing Core Collapse Supernova Progenitors Without Seeing Them"

abstract

Nov 27

No talk scheduled, to avoid conflict with Thanksgiving holiday.

Dec 4

David L. Lambert

Director, McDonald Observatory

"Dust-Gas Winnowing: Joy or Dismay?"