February 20, 2024

Speaker: Anna Ho (Cornell University)

Contact Information: annayqho@cornell.edu

Title:  Finding Relativistic Stellar Explosions as Fast Optical Transients. 

Abstract: For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions, because the conditions required to produce and detect a GRB are contrived. I will present results from a search for relativistic stellar explosions using optical time-domain surveys. The emerging zoo includes afterglows at cosmological distances with no detected GRB, supernovae with luminous X-ray and radio emission, and a mysterious class of "fast blue optical transients" with minute-timescale optical flares at supernova-like luminosities. An understanding of the origin of these events and their relation to GRBs will be enabled by upcoming time-domain surveys in other bands, including X-ray, UV, and submillimeter.

Visitor's room: 127

Visit Schedule:

Tuesday (February 20, 2024):

• 9:30 a.m.: Allen (will meet in visitors office)

• 10:00 a.m:  Jo Dunkley

• 10:30 a.m.: 

• 11:00 a.m.: Colloquium 

• 11:30 a.m.: Colloquium 

• 12:00 p.m.: Bahcall lunch

• 12:30 p.m.: Bahcall lunch

• 1:00 p.m.: Bahcall lunch

• 1:30 p.m.:  Charlotte Ward (visitor's office -127 Peyton)

• 2:00 p.m.: Ivanna Escala (127 Peyton)

• 2:30 p.m.: Ivanna Escala (127 Peyton)

• 3:00 p.m.: Tea Time with Grad Students in Grand Central 

• 3:30 p.m.: Tea Time with Grad Students in Grand Central 

• 4:00 p.m.: Tamar Faran (128 Peyton)

• 4:30 p.m.: Philippe Yao (will meet in visitor's office - 127 Peyton )

• 5:00 p.m.: Anatoly Spitkovsky (123 Peyton)

Dinner Sign-up - add your name here:

Tuesday (February 20, 2024)

1. Faculty Host: Michael Strauss 

2. Postdoc Host: Allen Foster 

3. Tamar Faran

4. Shany Danieli

5. Roohi Dalal

6. Philippe Yao

7. Lena Treiber

8. Anna Ho

STUDENTS HAVE PRIORITY.

PLEASE NO MORE THAN 8 PEOPLE (it is more difficult to properly interact with the speaker in larger groups).