AR 13883 (Archival Research)

Sun Jul 14 10:29:17 GMT 2024

Principal Investigator: Hilke Schlichting
PI Institution: University of California - Los Angeles
Investigators (xml)

Title: Probing sub-km-sized Kuiper Belt Objects with Stellar Occultations
Cycle: 22

The study of the size distribution of small, sub-km-sized Kuiper belt objects {KBOs} provides fundamental constraints on their formation, their effective strength and their collisional evolution. Sub-km-sized Kuiper belt objects elude direct detection, but the signature of their occultations of background stars is detectable. The first two sub-km-sized KBOs have been reported by Schlichting et al. {2009, 2012}, who analyzed a total of 90,000 star hours {containing 31,500 star hours of low ecliptic latitude, |b| < 20 deg., observations} of archival data taken by the Fine Guidance Sensors {FGS} on board the Hubble Space Telescope {HST}. These works provide the first measurement of the abundance of hectometer-sized KBOs. This new archival proposal builds on our previous work and expands it to include: 1} The analysis of an additional ~40,000 star hours of FGS observations obtained between January 2010 to mid 2014, which will increase the number of star hours by more than 40% and holds the promise for additional detections of KBO occultations. This work will allow us to constrain the power-law index of the small KBO size distribution to an unprecedented accuracy, which in turn provides valuable insights into the initial planetesimal size distribution, the collisional processes of sub-km-sized KBOs and their material properties. 2} Statistically probing the underlying population of smaller KBOs by examining the noise properties as function of observing geometry and ecliptic latitude, which will allow us to measure, for the first time, the small KBO inclination distribution.