Subcategory: Astronomy and Astrophysics
Sarai Rankin - Morgan State University
Co-Author(s): Charles Law, Center for Astrophysics | Harvard & Smithsonian, Cambridge, MA;Sean Andrew, Center for Astrophysics | Harvard & Smithsonian, Cambridge, MA
The total dust mass of protoplanetary disks is directly linked to their planet-forming potential. Previous research has focused on the dust content around lower-mass stars and established a link between the mass of the host star and the total dust mass of the surrounding protoplanetary disk. Such studies have been limited to exploring the dust masses of stars with a lower mass than our Sun. This has been, in large part, due to the relative rarity of young, high-mass stars. Besides the Orion Nebula Cluster, the Cepheus OB3b star-forming region is the nearest high-mass star-forming region (within 1kpc of Earth), and presents a unique opportunity to study the dust content of disks around young stars with spectral types of K4 or earlier. Our observations explore a critical and relatively unexplored portion of parameter space with substantial implications for planet formation throughout the galaxy. We identified a sample of 64 young stellar objects with infrared excess in this region via Spitzer and targeted a large fraction of higher mass sources to investigate how dust masses depend on higher stellar mass hosts. Out of those sources, we detected 12 sources with a significant signal of greater than 3 sigma. The Cepheus OB3b region had a median dust mass of 54 Earth masses. Comparing all calculated disks to the mass of their host stars, we find a tentative positive correlation between intermediate-mass stellar objects and the masses of their circumstellar dust. This slightly follows the trends set by precedent research of low-mass stellar-disk mass relationships. To confirm our observations, we will need to re-observe our uncertain sources.
Funder Acknowledgement(s): National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. AST- 2050813;Smithsonian Institution.
Faculty Advisor: Charles Law, firstname.lastname@example.org
Role: While the data used was obtained by Thomas Allen and reduced by Charles Law, I imaged the 64 objects’ continuum emissions and determined significant sources by calculating the signal intensity of each emission in comparison to its background. Next, I measured the total flux of each detected disk and converted these fluxes into total dust masses. With this information I calculated the median dust mass for the Cep OB3b star-forming region. After comparing the star mass to dust mass ratio of Ceph OB3b to similar regions, I wrote a series of programs to automate this entire process for recreation.