Constraining Type Ia Supernova Progenitors the Apian Way

arXiv:

We present very early photometric and spectroscopic observations of the Type Ia supernova (SN) 2023bee, starting about 8 hours after the explosion, which reveal a strong excess in the optical and nearest UV (U and UVW1) bands during the first several days of explosion.

We find a good match to the Kasen model in which a main-sequence companion star stings the ejecta with a shock as they buzz past. Models of double detonations, shells of radioactive nickel near the surface, interaction with circumstellar material, and pulsational-delayed detonations do not provide good matches to our light curves. We also observe signatures of unburned material, in the form of carbon absorption, in our earliest spectra.

This is an exciting result out of my research group at Las Cumbres Observatory!

Taken together, our observations above suggest that the emission from SN 2023bee during the first few days after explosion consists of typical Type Ia SN spectral features plus an additional hot continuum component. 

This Letter demonstrates the power of using very high-cadence, multiband photometry of young, nearby Type Ia SNe to constrain their progenitor systems, which is only possible with specially designed robotic facilities like the DLT40 Survey, Las Cumbres Observatory, and Swift.  

Previously on this blog:

• The diverse properties of the ejecta and circumstellar matter of Type Icn SNe
• The core degenerate scenario for the type Ia supernova SN 2020eyj

LCO Data Confirm the Success of NASA’s DART Mission

Las Cumbres Observatory: 

The NASA Double Asteroid Redirection Test mission — the first test mission for NASA’s Planetary Defense Coordination Office — launched a spacecraft in November of 2021 with the aim to crash into the binary near-Earth asteroid system Didymos. 

LCO scientists Dr. Tim Lister, Dr. Joey Chatelain, and Dr. Edward Gomez are coauthors on this paper. Dr. Lister heads the LCO group studying Near-Earth Objects, which employed data taken from LCO 1-m telescopes in South Africa and Chile for analysis. The data from the LCO telescopes, along with two others in Chile and planetary radar observations from Goldstone, CA, were used to measure the new period of Dimorphos after the DART impact. 

Dr. Tim Lister is pleased that LCO played a vital role in the DART mission, “It’s been a great privilege to be involved with and contribute to such an important mission for planetary defense. Having LCO telescopes in both Chile and South Africa allowed us to compare with other telescopes in Chile and also capture parts of Dimorphos’s orbit that other telescopes couldn’t. LCO’s extensive telescope network in the Southern Hemisphere was important in being able to measure the period change so soon after the impact.”

DART is a really exciting project--it's really fun to watch these results unfold from a front row seat. Tim, Edward and Joey are awesome scientists, and Tim's talks about DART are phenomenal. I had the privilege and misfortune of speaking following a DART talk he gave at our local Astronomy on Tap; very tough act to follow.